Endangered and Threatened Wildlife and Plants; Foothill Yellow-Legged Frog; Threatened Status With Section 4(d) Rule for Two Distinct Population Segments and Endangered Status for Two Distinct Population Segments, 73914-73945 [2021-27512]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 246 (Tuesday, December 28, 2021)]
[Proposed Rules]
[Pages 73914-73945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27512]



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Vol. 86

Tuesday,

No. 246

December 28, 2021

Part III





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Foothill Yellow-Legged 
Frog; Threatened Status With Section 4(d) Rule for Two Distinct 
Population Segments and Endangered Status for Two Distinct Population 
Segments; Proposed Rule

Federal Register / Vol. 86 , No. 246 / Tuesday, December 28, 2021 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2021-0108; FF09E21000 FXES1111090FEDR 223]
RIN 1018-BE90


Endangered and Threatened Wildlife and Plants; Foothill Yellow-
Legged Frog; Threatened Status With Section 4(d) Rule for Two Distinct 
Population Segments and Endangered Status for Two Distinct Population 
Segments

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list four of six distinct population segments (DPSs) of the foothill 
yellow-legged frog (Rana boylii), a stream dwelling amphibian from 
Oregon and California, under the Endangered Species Act of 1973 (Act), 
as amended. This determination also serves as our 12-month finding on a 
petition to list the foothill yellow-legged frog. After a review of the 
best scientific and commercial information available, we find that 
listing the South Sierra and South Coast DPSs as endangered and the 
North Feather and Central Coast DPSs as threatened is warranted. 
Accordingly, we propose to list these four DPSs under the Act, with the 
South Sierra and South Coast DPSs listed as endangered species, and the 
North Feather and Central Coast DPSs listed as threatened species. Our 
proposal to list the North Feather and Central Coast DPSs as threatened 
species also includes a rule issued under section 4(d) of the Act for 
each of these two DPSs. If we finalize this proposed rule for these 
four DPSs, we will then add them to the List of Endangered and 
Threatened Wildlife and extend the Act's protections to them. We have 
determined that designation of critical habitat for these four DPSs is 
not determinable at this time. We have also determined that the North 
Coast DPS (in Oregon and northern California) and the North Sierra DPS 
(in Yuba, Sierra, Nevada, and Placer Counties, California) of the 
foothill yellow-legged frog do not warrant listing at this time.

DATES: We will accept comments received or postmarked on or before 
February 28, 2022. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. Eastern Time on the closing date. We must receive requests for a 
public hearing, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by February 11, 2022.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter the docket number or RIN 
for this rulemaking (presented above in the document headings). For 
best results, do not copy and paste either number; instead, type the 
docket number or RIN into the Search box using hyphens. Then, click on 
the Search button. On the resulting page, in the Search panel on the 
left side of the screen, under the Document Type heading, check the 
Proposed Rule box to locate this document. You may submit a comment by 
clicking on ``Comment.''
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R8-ES-2021-0108, U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Information Requested, below, for more information).

FOR FURTHER INFORMATION CONTACT: Michael Fris, Field Supervisor, U.S. 
Fish and Wildlife Service, Sacramento Fish and Wildlife Office, 2800 
Cottage Way, Sacramento, CA 95825; telephone 916-414-6700. Persons who 
use a telecommunications device for the deaf (TDD) may call the Federal 
Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species warrants 
listing if it meets the definition of an endangered species (in danger 
of extinction throughout all or a significant portion of its range) or 
a threatened species (likely to become endangered in the foreseeable 
future throughout all or a significant portion of its range). If we 
determine that a species warrants listing, we must list the species 
promptly and designate the species' critical habitat to the maximum 
extent prudent and determinable. We have determined that the South 
Sierra and South Coast DPSs meet the definition of an endangered 
species and the North Feather and Central Coast DPSs meet the 
definition of threatened species; therefore, we are proposing to list 
them as such. We have determined that designation of critical habitat 
for these four DPSs is not determinable at this time. We have 
determined that listing the North Coast and North Sierra DPSs is not 
warranted at this time. Both listing a species as an endangered or 
threatened species and designating critical habitat can be completed 
only by issuing a rule through the Administrative Procedure Act 
rulemaking process.
    What this document does. We propose to list two DPSs as endangered 
species (South Sierra and South Coast DPSs) and two DPSs as threatened 
species (North Feather and Central Coast DPSs) under the Act. We also 
propose a rule under section 4(d) of the Act for each of those DPSs we 
are proposing to list as threatened species.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that the following threats are 
driving the status of the foothill yellow-legged frog: Altered 
hydrology (largely attributable to dams, water diversions, channel 
modifications), nonnative species, and the effects of climate change 
(exacerbating drought, high-severity wildfire, extreme flood 
conditions). Other threats currently impacting the species include 
disease and parasites, agriculture (including pesticide drift), mining, 
urbanization (including development and roads) and recreation.
    Section 4(a)(3) of the Act requires the Secretary of the Interior 
(Secretary) to designate critical habitat concurrent with listing to 
the maximum extent prudent and determinable. Due to a court-ordered 
settlement agreement for completing our 12-month finding for the 
species, we have not been able to obtain the necessary economic 
information needed to develop a proposed critical habitat designation 
for the foothill yellow-legged frog. Therefore, we find that 
designation of critical habitat for this species is currently not 
determinable. Once we obtain the necessary economic information, we 
will propose a critical habitat designation for the species.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be

[[Page 73915]]

based on the best scientific and commercial data available and be as 
accurate and as effective as possible. Therefore, we request comments 
or information from other governmental agencies, Native American 
Tribes, the scientific community, industry, or any other interested 
parties concerning this proposed rule.
    We particularly seek comments concerning:
    (1) The species' biology, range, and population trends, including:
    (a) Biological or ecological requirements of the species, including 
habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns, 
and the locations of any additional populations of this species;
    (d) Historical and current population levels, and current and 
projected population trends; and
    (e) Past and ongoing conservation measures for the species and its 
habitat and their effectiveness.
    (2) Factors that may affect the continued existence of the species, 
which may include habitat modification or destruction, overutilization, 
disease, predation, the inadequacy of existing regulatory mechanisms, 
or other natural or manmade factors.
    (3) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species and existing regulations 
that may be addressing those threats.
    (4) Information on regulations that are necessary and advisable to 
provide for the conservation of the foothill yellow-legged frog and 
that the Service can consider in developing a 4(d) rule for the 
species. In particular, we seek information concerning the extent to 
which we should include any of the Act's section 9 prohibitions in the 
4(d) rule or whether we should consider any additional exceptions from 
the prohibitions in the 4(d) rule.
    (5) The reasons why we should or should not designate habitat as 
``critical habitat'' under section 4 of the Act (16 U.S.C. 1531 et 
seq.), including information to inform the following factors that the 
regulations identify as reasons why designation of critical habitat may 
be not prudent:
    (a) The species is threatened by taking or other human activity and 
identification of critical habitat can be expected to increase the 
degree of such threat to the species;
    (b) The present or threatened destruction, modification, or 
curtailment of a species' habitat or range is not a threat to the 
species, or threats to the species' habitat stem solely from causes 
that cannot be addressed through management actions resulting from 
consultations under section 7(a)(2) of the Act;
    (c) Areas within the jurisdiction of the United States provide no 
more than negligible conservation value, if any, for a species 
occurring primarily outside the jurisdiction of the United States; or
    (d) No areas meet the definition of critical habitat.
    (6) Specific information on:
    (a) The amount and distribution of foothill yellow-legged frog 
habitat; and
    (b) What areas, which are either (i) occupied at the time of 
listing and that contain the physical or biological features essential 
to the conservation of the species and which may require special 
management considerations or protection; or (ii) unoccupied at the time 
of listing and are essential for the conservation of the species, and 
would, with reasonable certainty, contribute to the conservation of the 
species.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include. Please 
note that submissions merely stating support for, or opposition to, the 
action under consideration without providing supporting information, 
although noted, will not be considered in making a determination, as 
section 4(b)(1)(A) of the Act directs that determinations as to whether 
any species is an endangered or a threatened species must be made 
``solely on the basis of the best scientific and commercial data 
available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the website. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov.
    Because we will consider all comments and information we receive 
during the comment period, our final determinations may differ from 
this proposal. Based on the new information we receive (and any 
comments on that new information), we may conclude that the appropriate 
listing status for any of the four DPSs is different than our 
determinations identified in this proposal, including the possibility 
that one or more of the DPSs may not warrant listing as either 
endangered or threatened. In addition, we may change the parameters of 
the prohibitions or the exceptions to those prohibitions in the 4(d) 
rule if we conclude it is appropriate in light of comments and new 
information we receive. For example, we may expand the prohibitions to 
include prohibiting additional activities if we conclude that those 
additional activities are not compatible with conservation of the 
species. Conversely, we may establish additional exceptions to the 
prohibitions in the final rule if we conclude that the activities would 
facilitate or are compatible with the conservation and recovery of the 
species.

Public Hearing

    Section 4(b)(5) of the Act (16 U.S.C. 1531 et seq.) provides for a 
public hearing on this proposal, if requested. Requests must be 
received by the date specified in DATES. Such requests must be sent to 
the address shown in FOR FURTHER INFORMATION CONTACT. We will schedule 
a public hearing on this proposal, if requested, and announce the date, 
time, and place of the hearing, as well as how to obtain reasonable 
accommodations, in the Federal Register and local newspapers at least 
15 days before the hearing. For the immediate future, we will provide 
these public hearings using webinars that will be announced on the 
Service's website, in addition to the Federal Register. The use of 
these virtual public hearings is consistent with our regulations at 50 
CFR 424.16(c)(3).

Previous Federal Actions

    On July 11, 2012, we received a petition from the Center for 
Biological Diversity to list 53 species of reptiles and amphibians, 
including the foothill yellow-legged frog, as endangered or threatened 
under the Act. On July 1, 2015, we published our finding that the 
petition presented substantial scientific or commercial information 
indicating that listing the foothill yellow-legged frog may be 
warranted based on impacts to the species' habitat (Factor A) and other 
natural or humanmade factors (Factor E) (80 FR 37568).
    On August 30, 2016, we entered into a settlement agreement with the 
Center

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for Biological Diversity to complete our 12-month finding on the 
foothill yellow-legged frog by September 30, 2020. We subsequently 
requested and received an extension of our deadline to submit the 12-
month finding on the species to the Federal Register by December 15, 
2021. This document fulfills our obligation under the settlement 
agreement to complete a 12-month finding on the foothill yellow-legged 
frog.

Supporting Documents

    A species status assessment (SSA) team prepared an SSA report for 
the foothill yellow-legged frog (Service 2021, entire). The SSA team 
was composed of Service biologists, in consultation with other species 
experts. The SSA report represents a compilation of the best scientific 
and commercial data available concerning the status of the species, 
including the impacts of past, present, and future factors (both 
negative and beneficial) affecting the species. In accordance with our 
joint policy on peer review published in the Federal Register on July 
1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and 
clarifying the role of peer review of listing actions under the Act, we 
sought and received the expert opinions of three appropriate 
specialists regarding the SSA. We also sent the SSA report to numerous 
Federal, State, Tribal, and private partners and stakeholders, 
including scientists with expertise in foothill yellow-legged frog 
ecology, river ecology, amphibian genetics, population modeling, and 
public land management, for review. We received comments from 12 of 
these partners including representatives from the U.S. Department of 
Agriculture's U.S. Forest Service (Forest Service), U.S. Geological 
Survey (USGS), Bureau of Land Management (BLM), National Park Service, 
Oregon Department of Fish and Wildlife (ODFW), California Department of 
Forestry and Fire Protection (CalFire), and researchers from the 
University of California at Los Angeles. We did not receive comments 
from any Tribal entities. Comments and feedback from partners and peer 
reviewers were incorporated into the SSA report as appropriate and have 
informed this proposed rule. A copy of the SSA report can be found on 
www.regulations.gov at Docket No. FWS-R8-ES-2021-0108.

I. Proposed Listing Determination

Background

    Below is a brief description of the foothill yellow-legged frog, 
its habitat, distribution, and taxonomy; for a thorough discussion of 
the ecology and life history of the species, please see the SSA report 
(Service 2021, Chapter 2, pp. 14-33).
    The foothill yellow-legged frog is a small- to medium-sized stream-
dwelling frog with fully webbed feet and rough pebbly skin. Coloring of 
the species is highly variable but is usually light and dark mottled 
gray, olive, or brown, with variable amounts of brick red. The foothill 
yellow-legged frog is a stream-obligate species. Stream habitat for the 
species is highly variable and keyed on flow regimes. The historical 
range of the foothill yellow-legged frog extended from the Willamette 
River drainage in Oregon south through the Sierra Nevada Mountains to 
the Transverse Range, and down along the California Coast Range to at 
least the Upper San Gabriel River in Los Angeles County, California. 
The current distribution of the foothill yellow-legged frog generally 
follows the historical distribution of the species except with range 
contractions in the southern and, to a lesser extent, northern parts of 
the species' range.

Taxonomy

    The foothill yellow-legged frog currently retains its 
classification as Rana boylii, ascribed in 1854 by S. F. Baird (Baird 
1854, p. 62; Frost 2019, unpaginated). Prior to1955, the foothill 
yellow-legged frog was part of a grouping of two Ranid subtaxa that 
occurred in Oregon and California. The two subtaxa were subsequently 
revised as two separate individual taxa in 1955 and identified as Rana 
boylii (foothill yellow-legged frog) and Rana muscosa (mountain yellow-
legged frog) (Zweifel 1955, pp. 210, 273). The foothill yellow-legged 
frog is now the only entity classified as Rana boylii (Zweifel 1968, 
pp. 71.1-71.2).

Genetic Information

    Subsequent to receipt of the petition to list the foothill yellow-
legged frog as a singular species, investigations into genetic 
differences among populations of the foothill yellow-legged frog have 
delineated the species into six currently identified genetic clades 
(Peek 2018, entire). A clade is a group of organisms that includes a 
common biological ancestor and all the lineal descendants. Two 
rangewide assessments of foothill yellow-legged frog genomic datasets 
revealed that the species is extremely differentiated following 
biogeographical boundaries (McCartney-Melstad et al. 2018, p. 112; Peek 
2018, p. 76). The foothill yellow-legged frog has deeper population 
structure (stratification or separation between populations) than that 
observed in any other anuran (i.e., frogs, toads, and tree frogs) with 
similar data (McCartney-Melstad et al. 2018, p. 112). The California 
Department of Fish and Wildlife (CDFW) in their recent status 
determination classified the foothill yellow-legged frog as having six 
unique, genetic clades (i.e., lineages) (CDFW 2019b, pp. 4, 13). 
Additional information regarding the genetic clades can be found in the 
SSA report (Service 2021, pp. 19-21). The six separate genetic clades 
are identified as the North Coast, North Feather, North Sierra, South 
Sierra, Central Coast, and South Coast clades in our analysis.

Distinct Population Segment Evaluation

    Under the Act, the term species includes any subspecies of fish or 
wildlife or plants, and any distinct population segment of any species 
of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 
1532(16)). To guide the implementation of the distinct population 
segment (DPS) provisions of the Act, we and the National Marine 
Fisheries Service (National Oceanic and Atmospheric Administration--
Fisheries), published the Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act (DPS 
Policy) in the Federal Register on February 7, 1996 (61 FR 4722). Under 
our DPS Policy, we use two elements to assess whether a population 
segment under consideration for listing may be recognized as a DPS: (1) 
The population segment's discreteness from the remainder of the species 
to which it belongs, and (2) the significance of the population segment 
to the species to which it belongs. If we determine that a population 
segment being considered for listing is a DPS, then the population 
segment's conservation status is evaluated based on the five listing 
factors established by the Act to determine if listing it as either 
endangered or threatened is warranted.
    Under the Act, we have the authority to consider for listing any 
species, subspecies, or, for vertebrates, any DPS of these taxa if 
there is sufficient information to indicate that such action may be 
warranted. Based on the information available regarding potential 
discreteness and significance for the species, we determined it was 
appropriate to review the status of the foothill yellow-legged frog by 
first conducting a DPS analysis for the species.

Discreteness

    Under our DPS Policy, a population segment of a vertebrate taxon 
may be considered discrete if it satisfies either of the following 
conditions: (1) It is markedly separated from other

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populations of the same taxon as a consequence of physical, 
physiological, ecological, or behavioral factors. Quantitative measures 
of genetic or morphological discontinuity may provide evidence of this 
separation; or (2) it is delimited by international governmental 
boundaries within which differences in control of exploitation, 
management of habitat, conservation status, or regulatory mechanisms 
exist that are significant in light of section 4(a)(1)(D) of the Act.
    For the foothill yellow-legged frog, we examined recent genetic 
information and distribution of the species' populations as our means 
of determining discreteness for potential DPSs.
    There is substantial evidence that the foothill yellow-legged frog 
is biogeographically divided into multiple clades with little or no 
gene flow between the clades. Earlier studies provided strong evidence 
that there are deep genetic divisions in this taxon (Dever 2007, pp. 
168-173; Lind et al. 2011, pp. 269-284; Peek 2010, entire). Subsequent, 
more in-depth and larger-scale genetic studies (McCartney-Melstead et 
al. 2018, entire; Peek 2018, entire) confirmed the certainty and depth 
of the phylogenetic (evolutionary history) structural divisions of the 
foothill yellow-legged frog using population genomics (comparison of 
DNA sequences of populations).
    The results of the first study (McCartney-Melstead et al. 2018, 
entire), which used several different analytical approaches, all 
supported extremely differentiated clades in a spatially cohesive 
pattern, and identified five reciprocally monophyletic clades (where 
each clade shares more-recent common ancestors from one clade than it 
shares with any other clade) associated with five different geographic 
regions (identified herein as the North Coast, Central Coast, South 
Coast, North Sierra, and South Sierra clades) (McCartney-Melstead et 
al. 2018, p. 112).
    The second genomic study (Peek 2018, entire) provided additional 
geographic and genetic resolution to clade divisions by examining 
genetic samples from 1,103 individual foothill yellow-legged frogs 
across the extant range of the species and provided greater coverage of 
localities in the northern Sierra Nevada range (Peek 2018, pp. 52-53). 
Like the earlier study, multiple analytical methods were used to 
quantify genetic structure. The study largely confirmed the five clades 
described by previous research (McCartney-Melstead et al. 2018, 
entire), but also identified another discrete group between the North 
Sierra and North Coast clade that is identified herein as the North 
Feather clade (Peek 2018, pp. 63-64). The extensive genomic data 
available for this species, which are both more reliable and more 
informative than morphological data, demonstrate discrete patterns of 
biogeographical discontinuity across the taxon's range.
    Some of the geographical boundaries that delineate the foothill 
yellow-legged frog clades are fairly certain because of clear physical 
barriers, such as the separation between the Sierra Nevada and Coastal 
clades due to the Central Valley of California, the San Francisco Bay 
between the North Coast and the Central Coast clades, or the separation 
of the Central Coast and South Coast clades due to the Salinas Valley. 
However, physical separation between clades in the Sierra Nevada and 
separation of the Sierra Nevada clades from the North Coast clade were 
not as physically apparent and were informed by continuous sampling 
efforts in neighboring watersheds between clades. Where continuous 
landscape-level sampling was unavailable, the clade boundaries were 
estimated or inferred. Information is currently lacking for the precise 
boundary separating the North Coast clade and the North Feather clade, 
and the Central Coast clade from the South Coast clade. Therefore, we 
relied upon the genetic information for assessment of discreteness in 
this DPS analysis.
    Meeting the first condition for discreteness, there are six 
statistically-supported discrete genetic entities (Central Coast, South 
Coast, South Sierra, North Sierra, North Feather, and North Coast) 
within the range of the foothill yellow-legged frog (see figure below). 
Two rangewide assessments of foothill yellow-legged frog genomic 
datasets revealed that this taxon is extremely differentiated by 
biogeographical boundaries (McCartney-Melstead et al. 2018, p. 112; 
Peek 2018, p. 76). All six entities, or clades, are markedly separate 
from each other, as evidenced by quantitative measures of genetic 
discontinuity, and at least five of the clades are monophyletic groups 
(McCartney-Melstead et al. 2018, p. 116). As a result, we have 
determined that the foothill yellow-legged frog is comprised of six 
discrete entities (North Coast, Central Coast, South Coast, North 
Feather, North Sierra, and South Sierra) meeting the condition of 
discreteness under our DPS policy.
BILLING CODE 4333-15-P

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[GRAPHIC] [TIFF OMITTED] TP28DE21.019

BILLING CODE 4333-15-C

Significance

    Under our DPS Policy, once we have determined that a population 
segment is discrete, we consider its biological and ecological 
significance to the larger taxon to which it belongs. This 
consideration may include, but is not limited to: (1) Evidence of the 
persistence of the discrete population segment in an ecological setting 
that is unusual or unique for the taxon, (2)

[[Page 73919]]

evidence that loss of the population segment would result in a 
significant gap in the range of the taxon, (3) evidence that the 
population segment represents the only surviving natural occurrence of 
a taxon that may be more abundant elsewhere as an introduced population 
outside its historical range, or (4) evidence that the discrete 
population segment differs markedly from other populations of the 
species in its genetic characteristics.
    We evaluated each discrete population segment to see if it met the 
conditions of significance under our DPS policy, and we have determined 
that the six entities are significant to the foothill yellow-legged 
frog.
    The support for significance of the six DPSs is based, in part, 
upon evidence that loss of any of these population segments would 
result in a significant gap in the range of the taxon. The loss of 
either the Central Coast or South Coast DPS would result in a 
substantial change in the overall range and distribution of the taxon. 
The loss of the South Coast DPS would shift the taxon's southwestern 
range boundary northward by approximately 150-200 kilometers (km) (93-
125 miles (mi)). The loss of the Central Coast DPS would leave an 
extensive separation of approximately 300 km (186 mi) and be a 
significant gap in the species' range. The loss of the South Sierra DPS 
would result in a considerable contraction of the taxon's range, making 
the species' range shift approximately 180 km (112 mi) west and 340 km 
(211 mi) north. The loss of the North Coast DPS would result in the 
loss of more than half of the taxon's current range. The North Sierra 
and North Feather DPSs occupy much smaller areas than the other DPSs. 
However, based on the current range of each of these DPSs, the loss of 
either would result in a 50-75 km (31-47 mi) gap in the range of the 
taxon. Due to the species' limited dispersal ability from occupied 
stream habitats, this gap would effectively prevent any potential 
future gene flow between the DPSs remaining on either side of the gap.
    The support for significance of the six DPSs is also based upon 
evidence that each discrete population segment differs markedly from 
all the others in its genetic characteristics. The loss of any of the 
six DPSs would result in the loss of a discrete genetic clade. The DPSs 
that are most genetically divergent, and thus contribute most to the 
overall adaptive capacity of this taxon, are the Central Coast, South 
Coast, and South Sierra DPSs (Peek 2018, p. 77). The North Feather and 
North Sierra DPSs likely have unique adaptive potential in the face of 
climate change because of their admixture history (interbreeding of 
isolated populations) and intermediacy to the South Sierra and North 
Coast DPSs. The North Coast DPS is also genetically valuable to the 
taxon because it contains the greatest genetic diversity and is the 
only DPS that shows a trajectory of increasing genetic diversity (Peek 
2018, p. 74).

Distinct Population Segment Conclusion

    Our DPS Policy directs us to evaluate whether populations of a 
species are separate from each other to the degree they qualify as 
discrete segments and whether those segments are significant to the 
remainder of the species to which it belongs. Based on an analysis of 
the best available scientific and commercial data, we conclude that the 
North Coast, North Feather, North Sierra, South Sierra, Central Coast, 
and South Coast clades of the foothill yellow-legged frog's range are 
each discrete due to their marked genetic separation. Furthermore, we 
conclude that each of the six clades of the foothill yellow-legged 
frog's range is significant, based on evidence that a loss of any of 
the population segments would result in a significant gap in the range 
of the taxon and on evidence that the discrete population segments 
differ markedly from other populations of the species in their genetic 
characteristics. Therefore, we conclude that the six clades within the 
foothill yellow-legged frog's range are both discrete and significant 
under our DPS Policy and are, therefore, uniquely listable entities 
under the Act.
    Based on our DPS Policy (61 FR 4722; February 7, 1996), if a 
population segment of a vertebrate species is both discrete and 
significant relative to the taxon as a whole (i.e., it is a distinct 
population segment), its evaluation for endangered or threatened status 
will be based on the Act's definition of those terms and a review of 
the factors enumerated in section 4(a) of the Act. Having found that 
each of the six clades of the foothill yellow-legged frog's range meet 
the definition of a distinct population segment, we then evaluated the 
status of the six clades of the foothill yellow-legged frog to 
determine whether any met the definition of an endangered or threatened 
species under the Act. The figure below identifies the areas within the 
foothill yellow-legged frog's historical range encompassed by the six 
DPSs for the foothill yellow-legged frog.

Description of Foothill Yellow-Legged Frog Distinct Population Segments

    Below is a general description of environmental and ecological 
conditions for each DPS.
    North Coast DPS: The North Coast DPS includes the range of the 
foothill yellow-legged frog in northern California and central and 
southwestern Oregon. This DPS occupies parts of the Cascade Range, 
Klamath Mountains, central and southwest Oregon (including the 
Willamette Valley), northern California Coast Range north of San 
Francisco Bay, and a portion of the Sierra Nevada Mountains and 
foothills to the borders of Plumas and Butte Counties, California. This 
DPS covers the largest geographic area and has the greatest amount of 
genetic diversity of the species, suggesting that habitat conditions 
allow for populations within the DPS to be interconnected (McCartney-
Melstad et al. 2018, p. 121; Peek 2018, p. 76). In Oregon, the area has 
the greatest precipitation and coolest temperatures within the species' 
range (PRISM Climate Group 2012, 30-year climate dataset, entire; 
Service 2021, table 3, p. 36). In California, the DPS is cooler and 
wetter on average than the DPSs to the south but is about equal to that 
of the North Sierra DPS (PRISM Climate Group 2012, 30-year climate 
dataset, entire; Service 2021, table 3, p. 36). The DPS also contains 
the most Level IV ecoregions (finest down-scaled ecosystems boundaries 
based on biotic and abiotic factors as defined by Omerick and Griffith 
2014, entire), as well as several ecoregions that are not found 
anywhere else in the foothill yellow-legged frog's range, suggesting 
that the environmental conditions for habitat within this DPS are 
variable and not likely to be subject to rangewide environmental 
influences.
    North Feather DPS: The North Feather DPS is located primarily in 
Plumas and Butte Counties, California. This DPS occupies the transition 
zone between the northern Sierra Nevada, Southern Cascades Foothills, 
and Tuscan Flows ecoregions. The DPS averages cooler and wetter 
conditions than the DPSs to the south (PRISM Climate Group 2012, 30-
year climate dataset, entire; Service 2021, table 3, p. 36). The North 
Feather DPS differs from the surrounding watersheds outside the areas 
in terms of geology and aspect (Peek et al. 2019, p. 4638), and is the 
only known area where the foothill yellow-legged frog and the 
endangered Sierra Nevada yellow-legged frog (Rana sierrae) currently 
coexist (Peek et al. 2019, p. 4637).
    North Sierra DPS: The North Sierra DPS is located primarily in 
Yuba, Sierra, Nevada, and Placer Counties, California. This DPS 
occupies the transition zone between the northern and central 
ecoregions of the Sierra Nevada Range. This transition zone is 
characterized by a southward decrease in annual

[[Page 73920]]

precipitation, decrease in Douglas and white firs (Pseudotsuga 
menziesii and Abies concolor), increase in ponderosa pine (Pinus 
ponderosa), and geological shift from metamorphic rocks to volcanic and 
granitic rocks (Environmental Protection Agency Level IV Ecoregions, 
Griffith et al. (2016, entire)). Like the North Feather DPS, the North 
Sierra DPS receives notably more precipitation than the South Sierra 
DPS; however, the mean annual temperature in the North Sierra DPS is 
more similar to that of the South Sierra DPS than that of the North 
Feather DPS (PRISM Climate Group 2012, 30-year climate dataset, entire; 
Service 2021, table 3, p. 36).
    South Sierra DPS: The South Sierra DPS extends from the South Fork 
American River sub-basin to the transition zone between the Sierra 
Nevada and the Tehachapi Mountains that border the south end of the 
California Central Valley. This DPS largely includes ecoregions that 
are unique to the southern and central Sierra Nevada Range 
(Environmental Protection Agency Level IV Ecoregions, Griffith et al. 
(2016, entire)). The South Sierra DPS also shares an ecoregion 
transition zone with the North Sierra DPS. In terms of average 
precipitation and temperature, the South Sierra DPS is fairly dry and 
warm, but it falls intermediately among the northern DPSs and the DPSs 
south of San Francisco Bay (PRISM Climate Group 2012, 30-year climate 
dataset, entire; Service 2021, table 3, p. 36).
    Central Coast DPS: The Central Coast DPS extends south from the San 
Francisco Bay through the Diablo Range and Coast Range (Santa Cruz 
Mountains and Gabilan Mountains) east of the Salinas Valley, 
California. On average, the Central Coast DPS receives the least amount 
of annual precipitation of all the DPSs (PRISM Climate Group 2012, 30-
year climate dataset, entire; Service 2021, table 3, p. 36). The DPS 
contains several unique ecoregions associated with the Diablo and Coast 
Ranges. Although the mountain ranges of the Central Coast DPS are 
geologically unique and separated from those of the South Coast DPS by 
the Salinas Valley, there are several attributes such as overall 
elevation, elevation grade, and some vegetation types (Environmental 
Protection Agency Level IV Ecoregions, Griffith et al. (2016, entire)) 
which they share in common with the South Coast DPS mountain ranges. 
Climatic and habitat conditions of the DPS are drier than all other 
DPSs except for the South Coast DPS, which has conditions similar to 
the Central Coast DPS, being warm and dry and containing waterways 
similar in size and hydrological properties (PRISM Climate Group 2012, 
30-year climate dataset, entire; Service 2021, table 3, p. 36).
    South Coast DPS: The South Coast DPS extends along the coastal 
Santa Lucia Range and the Sierra Madre Mountains in California. 
Ecoregions that are unique to the South Coast DPS include those 
associated with the Santa Lucia Range, Western Transverse Range, and 
Southern California Lower Montane Shrub and Woodland (Environmental 
Protection Agency Level IV Ecoregions, Griffith et al. (2016, entire)). 
As stated above, the streams and rivers in the South Coast DPS share 
similarities to many waterways in the Central Coast DPS. Waterways in 
the South Coast and Central Coast DPSs tend to have flashier flows, 
more ephemeral channels, and a higher degree of intermittency because 
of the region's more variable, and lower amount of, precipitation 
(Storer 1925, pp. 257-258; Gonsolin 2010, p. 54; Adams et al. 2017b, p. 
10227). The South Coast and Central Coast DPSs receive the least amount 
of annual precipitation and average the warmest temperatures within the 
species' range (PRISM Climate Group 2012, 30-year climate dataset, 
entire; Service 2021, table 3, p. 36).

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species is an endangered species or a threatened species. The 
Act defines an endangered species as a species that is in danger of 
extinction throughout all or a significant portion of its range, and a 
threatened species as a species that is likely to become an endangered 
species within the foreseeable future throughout all or a significant 
portion of its range. The Act requires that we determine whether any 
species is an endangered species or a threatened species because of any 
of the following factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the expected response by the species, 
and the effects of the threats--in light of those actions and 
conditions that will ameliorate the threats--on an individual, 
population, and species level. We evaluate each threat and its expected 
effects on the species, then analyze the cumulative effect of all of 
the threats on the species as a whole. We also consider the cumulative 
effect of the threats in light of those actions and conditions that 
will have positive effects on the species, such as any existing 
regulatory mechanisms or conservation efforts. The Secretary determines 
whether the species meets the definition of an endangered species or a 
threatened species only after conducting this cumulative analysis and 
describing the expected effect on the species now and in the 
foreseeable future.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis. The term 
``foreseeable future'' extends only so far into the future as the 
Service can reasonably determine that both the future threats and the 
species' responses to those threats are likely. In other words, the 
foreseeable future is the period of time in which we can make reliable 
predictions. ``Reliable'' does not mean ``certain''; it means 
sufficient to provide a reasonable degree of confidence in the 
prediction. Thus, a

[[Page 73921]]

prediction is reliable if it is reasonable to depend on it when making 
decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors. For information regarding the foreseeable 
future for the foothill yellow-legged frog, see Current and Future 
Condition Analysis, below.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
threats to the species. The SSA report does not represent a decision by 
the Service on whether the species should be proposed for listing as an 
endangered or threatened species under the Act. However, it does 
provide the scientific basis that informs our regulatory decisions, 
which involve the further application of standards within the Act and 
its implementing regulations and policies. The following is a summary 
of the key results and conclusions from the SSA report; the full SSA 
report can be found at Docket FWS-R8-ES-2021-0108 on https://www.regulations.gov and from the Sacramento Fish and Wildlife Office 
(see FOR FURTHER INFORMATION CONTACT).
    Our review of the foothill yellow-legged frog has determined that 
it is made up of six DPSs; therefore, we assessed the biological 
viability and regulatory status of each DPS separately. Because the 
North Coast DPS of the foothill yellow-legged frog occurs in Oregon and 
California, we split the North Coast DPS into a California and an 
Oregon analysis unit due to varying levels of information and to better 
understand if any management actions or habitat conditions may differ 
between the two areas (Service 2021, Chapter 3, pp. 35-36). We later 
combine the two analysis units to determine the status of the North 
Coast DPS as a whole. When we discuss general biological or other 
information regarding the species as a whole we use the term species. 
When we discuss information pertaining to one of the six DPSs we use 
the term DPS.
    To assess the biological viability of each DPS of the foothill 
yellow-legged frog, we used the three conservation biology principles 
of resiliency, redundancy, and representation (Shaffer and Stein 2000, 
pp. 306-310). Briefly, resiliency supports the ability of the DPS to 
withstand environmental and demographic stochasticity (for example, wet 
or dry, warm or cold years), redundancy supports the ability of the DPS 
to withstand catastrophic events (for example, droughts, large 
pollution events), and representation supports the ability of the DPS 
to adapt over time to long-term changes in the environment (for 
example, climate changes). In general, the more resilient and redundant 
a DPS is and the more representation it has, the more likely it is to 
sustain populations over time, even under changing environmental 
conditions.
    Using these principles, we identified each DPS's ecological 
requirements for survival and reproduction at the individual, 
population, and DPS levels, and described the beneficial and risk 
factors influencing the DPS's viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical 
and current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. Throughout all of these 
stages, we used the best available information to characterize 
viability as the ability of a species to sustain populations in the 
wild over time. We use this information to inform our regulatory 
decision. In our development of the SSA and analysis of information, we 
divided our analysis into separate analysis units due to the varying 
degree of information throughout the species' range and other factors. 
The analysis units coincide with those areas we are considering as DPSs 
for the species except for the North Coast DPS which has been split 
into two analysis units. In California, the analysis units match those 
considered in the CDFW's evaluation for their status review and listing 
under the California Endangered Species Act.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of each DPS 
and its resources, and the threats that influence each DPS's current 
and future condition, in order to assess each DPS's overall viability 
and the risks to that viability.
    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have not 
only analyzed individual effects on each DPS, but we have also analyzed 
their potential cumulative effects. We incorporate the cumulative 
effects into our SSA analysis when we characterize the current and 
future condition of each DPS. To assess the current and future 
condition of each DPS, we undertake an iterative analysis that 
encompasses and incorporates the threats individually and then 
accumulates and evaluates the effects of all the factors that may be 
influencing each DPS, including threats and conservation efforts. 
Because the SSA framework considers not just the presence of the 
factors, but to what degree they collectively influence risk to the 
entire DPS, our assessment integrates the cumulative effects of the 
factors and replaces a standalone cumulative effects analysis.

Species Needs

Stream Habitat
    The foothill yellow-legged frog is a stream-obligate species and is 
primarily observed in or along the edges of streams (Zweifel 1955, p. 
221; Kupferberg 1996a, p. 1339). Most foothill yellow-legged frogs 
breed along mainstem water channels and overwinter along smaller 
tributaries of the mainstem channel (Kupferberg 1996a, p. 1339; GANDA 
2008, p. 20). Habitat within the stream includes rocky substrate mostly 
free of sediments with interstitial spaces to allow for predator 
avoidance. Stream morphology is a strong predictor of breeding habitat 
because it creates the microhabitat conditions required for successful 
oviposition (i.e., egg-laying), hatching, growth, and metamorphosis. 
Foothill yellow-legged frogs that overwinter along tributaries often 
congregate at the same breeding locations along the mainstem each year 
(Kupferberg 1996a, p. 1334; Wheeler and Welsh 2008, p. 128). During the 
nonbreeding season, the smaller tributaries, some of which may only 
flow during the wet winter season, provide refuge while the larger 
breeding channels may experience overbank flooding and high flows 
(Kupferberg 1996a, p. 1339). Habitat elements that provide both refuge 
from winter peak flows and adequate moisture for foothill yellow-legged 
frogs include pools, springs, seeps, submerged root wads, undercut 
banks,

[[Page 73922]]

and large boulders or debris at high-water lines (van Wagner 1996, pp. 
74-75, 111; Rombough 2006b, p. 159).
    The streams occupied by foothill yellow-legged frogs occur in a 
wide variety of vegetation types including valley-foothill hardwood, 
valley-foothill hardwood-conifer, valley-foothill riparian, ponderosa 
pine, mixed conifer, mixed chaparral, and wet meadow (Hayes et al. 
2016, p. 5). The extensive range of habitat types used by the foothill 
yellow-legged frog demonstrates the species' non-specificity in regard 
to vegetation type and macroclimate of the species' terrestrial habitat 
component. While habitat conditions can be vastly different among these 
stream sizes, and across the species' geographic range, only a narrow 
range of abiotic conditions are tolerated by early life stages (i.e., 
eggs, tadpoles, and metamorphs) (Kupferberg 1996a, p. 1336; Bondi et 
al. 2013, p. 101; Lind et al. 2016, p. 263; Catenazzi and Kupferberg 
2018, pp. 1044-1045). The abiotic conditions that directly influence 
the success of early life stages are those associated with stream 
velocity, water depth, water temperature, and streambed substrate. 
Foothill yellow-legged frogs also require stream flow regimes to have 
or mimic natural flow patterns which includes high winter flows with a 
slowly diminishing hydrograph with increasing water temperature and 
decreasing flows into the spring and summer. Higher winter flows can 
maintain and or increase breeding habitat by widening and diversifying 
channel morphology, improving rocky substrate conditions, and 
increasing sunlight (Lind et al. 1996, pp. 64-65; Lind et al. 2016, p. 
269; Power et al. 2016, p. 719). The reduction in flows and increasing 
water temperatures are also cues to initiate breeding. As a result, 
foothill yellow-legged frogs rely on natural, predictable changes 
during the hydrological cycle to optimize early life-stage growth and 
survival (Kupferberg 1996a, p. 1332; Bondi et al. 2013, p. 100).
Food Resources
    During their lifecycle foothill yellow-legged frogs feed on a 
variety of plant and animals. During early development food sources 
include algae, diatoms, and detritus that are scraped from submerged 
rocks and vegetation (Ashton et al. 1997, p. 7; Fellers 2005, p. 535). 
Juvenile and adult foothill yellow-legged frogs prey upon many types of 
aquatic and terrestrial invertebrates including snails, moths, flies, 
water striders, beetles, grasshoppers, hornets, and ants (Nussbaum et 
al. 1983, p. 165).
Migration/Dispersal Routes and Connectivity
    Adult foothill yellow-legged frogs primarily use waterway corridors 
to migrate or disperse (Bourque 2008, p. 70) and make their movements 
over multiple days (GANDA 2008, p. 22). While most foothill yellow-
legged frogs are found in, or very close to, water, juveniles and an 
adult have also been observed moving through upland areas outside of 
riparian corridors. The habitat characteristics needed by foothill 
yellow-legged frogs for migration and dispersal are largely the same as 
they are for upland and tributary habitat. However, movement routes do 
not need to be moist for extended periods. Routes need to connect 
breeding areas and overwintering habitat without exposing frogs to 
large physical barriers (e.g., roads, development, reservoirs) or high 
risk of predation. These migration and dispersal routes provide for 
metapopulation connectivity and allows for ease of mobility (for post-
metamorphic frogs) within a metapopulation and between different 
metapopulations. Both breeding/rearing and overwintering sites need to 
be distributed across the metapopulation area. Foothill yellow-legged 
frog occupancy (i.e., presence of breeding adults in a given area) must 
also be well distributed, such that dispersers are able to repopulate 
extirpated areas of the metapopulation. A resilient foothill yellow-
legged frog metapopulation should have a network of quality breeding/
rearing sites (often on or near the mainstem channel) and overwintering 
sites (often on tributaries of the mainstem) that are connected by 
habitat suitable for migration and dispersal (Section 4.9 Migration and 
Dispersal Routes). An in-depth discussion of habitat and population 
elements required for the foothill yellow-legged frog is in the SSA 
report (Service 2021, Chapter 4 and Chapter 5).

Threats Influencing Current and Future Condition

    Following are summary evaluations of the threats analyzed in the 
SSA report for the foothill yellow-legged frog. The discussion focuses 
on general threats impacting all DPSs, with some anecdotal evidence 
regarding threats operating in particular DPSs. The specific threats 
associated with each DPS are identified in the status discussion for 
each DPS below and in the SSA report (Service 2021, Chapter 7, pp. 73-
122).
    Those threats having the greatest impacts on the species or its 
habitat include: Altered stream hydrology and flow regimes (Factor A) 
associated with dams, surface water diversions, and channel 
modifications and their impact on the species and its habitat; 
predation and resource competition from nonnative species (Factor C and 
Factor E, respectively), such as American bullfrogs (Lithobates 
catesbeianus), smallmouth bass (Micropterus dolomieu), and crayfish 
species (Pacifastacus spp.); disease (Factor C); habitat degradation, 
loss, and fragmentation associated with wildfire (Factor A); the 
effects of climate change, including increased temperatures, drying and 
drought, and extreme flood events (Factor E); habitat modification and 
altered hydrology as a result of conservation efforts for salmonid 
species (colder water temperatures, timing and intensity of water 
flows) (Factor E); habitat loss, degradation, and fragmentation (Factor 
A), and direct negative effects to individuals (Factor E) from other 
anthropogenic activities such as agriculture, mining, urbanization, 
roads, and recreation. Within our threat discussion, we also evaluate 
existing regulatory mechanisms (Factor D) and ongoing conservation 
measures that may ameliorate threat impacts on the species.
    Livestock grazing and timber harvest were discussed as potential 
threats and potential beneficial influences in the recent status 
assessment for the foothill yellow-legged frog in California (CDFW 
2019b, pp. 64-65, 67). These activities were also considered in the 
conservation assessment developed by the Forest Service and BLM as part 
of their sensitive species program for the species in Oregon (Olson and 
Davis 2009, pp. 18-20). While there is potential for harm to the 
species (e.g., when grazing and timber practices cause excessive 
erosion and sedimentation into streams), there are also potential 
positive benefits to foothill yellow-legged frog habitat from these 
practices (Olson and Davis 2009, pp. 18-20; CDFW 2019b, pp. 64-65, 67). 
We captured and evaluated the potential negative impacts associated 
with grazing and timber harvest (e.g., water impoundments for cattle, 
erosion, logging roads) in our assessment of altered hydrology, 
sedimentation, and roads. For full descriptions of all threats and how 
they impact the species, please see the SSA report (Service 2021, pp. 
72-121).
Altered Stream Hydrology and Flow Regimes
    Foothill yellow-legged frog ecology and habitat needs are closely 
tied to the natural hydrological cycle of the streams

[[Page 73923]]

they inhabit. Foothill yellow-legged frog breeding and recruitment are 
dependent upon specific stream morphologies and upon predictable 
hydrological patterns that are synchronized with other climatic cues 
for foothill yellow-frog populations to be successful (Kupferberg 
1996a, p. 1337). Strong stream flow events typical during winter under 
natural flow regimes help maintain and create foothill yellow-legged 
frog breeding habitat by widening and diversifying channel morphology, 
improving rocky substrate conditions, removing sediment, and increasing 
sunlight by limiting vegetation encroachment (Lind et al. 1996, pp. 64-
65; Lind et al. 2016, p. 269; Power et al. 2016, p. 719; GANDA 2018, 
pp. 37-38). Dams, water management, and other waterway modifications 
alter the hydrology, timing, temperature, and morphology of foothill 
yellow-legged frog stream habitat (Service 2021, pp. 74-79). 
Alterations to flow regimes also occur for hydropeaking (for energy 
production) and recreational activities, such as spring and summer 
releases for whitewater boating (Kupferberg et al. 2012, p. 518) (see 
``Recreation,'' below). These pulse flows are generally much greater in 
frequency and intensity as compared to other flow fluctuations and, 
during spring and summer, can detrimentally affect early life stages of 
foothill yellow-legged frog during breeding and rearing season (Greimel 
et al. 2018, p. 92, Kupferburg et al. 2009c, Kupferburg et al., 2011b, 
p.144). Therefore, alterations of stream hydrology and flows can have a 
large influence on foothill yellow-legged frog distribution and 
metapopulation dynamics (Hayes et al. 2016, pp. 24-25; Service 2021, 
figure 21, p. 25).
    The effects of altered streams also impede foothill yellow-legged 
frog dispersal and metapopulation connectivity, which can prevent 
recolonization of extirpated areas and cause genetic bottlenecks (Peek 
2010, p. 44; Peek 2012, p. 15). Genetic comparisons among 
subpopulations demonstrated that gene flow is decreased in regulated 
river systems, even when the amount of regulation is low (Peek 2012, p. 
15; Peek et al. 2021, p. 14).
    Many population declines across the foothill yellow-legged frog's 
range have been attributed to the altered flow regimes and habitat 
fragmentation associated with water storage and hydropower dams 
(Kupferberg et al. 2009c, p. ix). Where populations of foothill yellow-
legged frogs persist in these areas, breeding population densities were 
more than five times smaller below dams than in free-flowing rivers 
(based on breeding populations in the North Coast DPS, North Feather 
DPS, and Central Coast DPS) (Kupferberg et al. 2012, p. 520). Dams and 
impoundments, as well as historical use of splash dams (temporary 
wooden dams created to facilitate transport of logs downstream) in the 
North Coast DPS in Oregon, have also presumably caused extirpations of 
the species and altered stream characteristics in some locations 
(Miller 2010, pp. 14, 61-63, 70-71, table 2.9; Linnell and Davis 2021, 
not paginated, figures 6 and 7).
    Altered flow regimes and water diversions (as well as several 
anthropogenic activities, such as mining, agriculture, overgrazing, 
timber harvest, and poorly constructed roads), as described in greater 
detail below, can cause or increase sedimentation in breeding habitat 
for the foothill yellow-legged frog (Moyle and Randall 1998, pp. 1324-
1325). Increased sedimentation can increase turbidity, impact algae and 
other food resources or impede foothill yellow-legged frog egg mass 
attachment to substrate (Cordone and Kelley 1961, pp. 191-192; Ashton 
et al. 1997, p. 13). Fine sediments can also fill interstitial spaces 
between rocks, which provide shelter from high velocity flows, cover 
from predators, and sources of aquatic invertebrate prey (Harvey and 
Lisle 1998, pp. 12-14; Olson and Davis 2009, p. 11; Kupferberg et al. 
2011b, pp. 147-149).
Predation
    Foothill yellow-legged frogs can be negatively affected by several 
native and nonnative animal species. The American bullfrog, native and 
nonnative fish, and nonnative crayfish have all been linked to 
impacting populations of foothill yellow-legged frogs (Olson and Davis 
2009, pp. 17-18; Hayes et al. 2016, pp. 49-51). The following 
discussion provides details on how these predatory species affect the 
foothill yellow-legged frog at various life stages through predation 
and competition.
    American bullfrogs: American bullfrogs are considered a threat to 
all six DPSs. Bullfrogs affect foothill yellow-legged frog populations 
in several ways because they are simultaneously competitors, predators, 
and disease vectors, and they impact life stages from tadpoles to 
adults (see figure 23 in the SSA report, Service 2021, p. 80). 
Bullfrogs impact foothill yellow-legged frogs by direct predation 
(Crayon 1998, p. 232; Hothem et al. 2009, pp. 279-280) and indirectly 
by reducing survival. In one experiment, the presence of bullfrog 
tadpoles reduced foothill yellow-legged frog tadpole survival by 48 
percent and mass at metamorphosis by 24 percent (Kupferberg 1997a, p. 
1736). Additionally, the algal and macroinvertebrate assemblages 
available to foothill yellow-legged frogs were significantly reduced 
due to the presence of bullfrog tadpoles (Kupferberg 1996b, p. 2; 
Kupferberg 1997a, p. 1736), which would negatively affect food sources 
for foothill yellow-legged frog tadpoles, juveniles, and adults. The 
spread of bullfrogs is facilitated by altered hydrology, land-use 
change, drought, and increasing water temperatures (Moyle 1973, p. 21; 
Fuller et al. 2011, pp. 210-211; Adams et al. 2017a, p. 13). Regulatory 
mechanisms to manage importation and distribution of bullfrogs are 
currently ineffective due to an inability to adequately enforce 
regulations (CDFW 2014, pp. 11-12).
    Fish: Fish such as smallmouth bass, green sunfish (Lepomis 
cyanellus), mosquitofish (Gambusia affinis), and trout (Oncorhynchus, 
Salmo, and Salvelinus spp.) are predators of foothill yellow-legged 
frogs and may also potentially compete with them for invertebrate food 
resources (Hayes et al. 2016, p. 51). However, of these fish, 
smallmouth bass are the greatest threat to foothill yellow-legged 
frogs. Adult smallmouth bass consume amphibian tadpoles (Kiesecker and 
Blaustein 1998, pp. 776-787), as well as foothill yellow-legged frog 
tadpoles and adults (Rombough 2006a, unpaginated; Paoletti et al. 2011, 
p. 166). Smallmouth bass have been identified as a potential cause of 
foothill yellow-legged frog declines and extirpations in Oregon 
(Rombough 2006a, unpaginated; Olson and Davis 2009, pp. 13, 17).
    The distribution of smallmouth bass in California includes the 
entire South Coast DPS and lower elevation areas of the South Sierra, 
North Sierra, and North Feather DPSs. Areas in the foothill yellow-
legged frog's range in the Salinas, Santa Clara, Central, and 
Sacramento Valleys are also within the range of the smallmouth bass. 
For the North Coast DPS, smallmouth bass occupy the Russian River, 
Trinity, and Eel River drainages (Conservation Biology Institute 2011, 
entire). In Oregon, smallmouth bass can be found in the entire range of 
the North Coast DPS except the extreme southeastern portion near the 
Klamath basin (Carey et al. 2011, p. 306).
    Nonnative crayfish: Several nonnative crayfish species prey upon 
early life stages of foothill yellow-legged frog. While the signal 
crayfish (Pacifastacus leniusculus) is native to part of the

[[Page 73924]]

North Coast DPS (i.e., Oregon and northwestern corner of California), 
it has been introduced into several areas within the coast ranges of 
northern California and the Sierra Nevada (Wiseman et al. 2005, p. 162; 
Pintor et al. 2009, p. 582; CDFW 2019b, p. 56). In both the native and 
introduced range of the signal crayfish, the species preys upon 
foothill yellow-legged frog egg masses, and likely contributes to 
dislodging egg masses from substrate, potentially allowing them to be 
transported to unsuitable habitat (Rombough and Hayes 2005, p. 163; 
Wiseman et al. 2005, p. 162). Signal crayfish are prey upon foothill 
yellow-legged frog tadpoles in laboratory settings (Kerby and Sih 2015, 
p. 266), and observations of tail injuries in wild tadpoles suggest 
crayfish predation also occurs in the wild (Rombough and Hayes 2005, p. 
163; Wiseman et al. 2005, p. 162).
Disease
    Foothill yellow-legged frogs can be negatively affected by 
amphibian chytrid fungus (Batrachochytrium dendrobatidis (Bd)), 
parasitic copepods, and Saprolegnia fungus (see figure 24 in the SSA 
report, Service 2021, p. 83).
    Bd is implicated in the declines or presumed extinctions of 
hundreds of amphibian species (Scheele et al. 2019, p. 1). The spread 
of Bd in the range of the foothill yellow-legged frog is presumably 
linked to increased human use of habitat and the introduction of 
nonnative bullfrogs, which are Bd reservoir hosts (Huss et al. 2013, p. 
341; Adams et al. 2017b, pp. 10225-10226; Yap et al. 2018, pp. 1-2; 
Byrne et al. 2019, p. 20386). The southern California precipitation 
regime (i.e., alternation of extreme droughts and floods) may increase 
the likelihood of disease outbreaks by causing favorable habitat 
conditions for bullfrogs, warmer water temperatures, and increased 
stress on foothill yellow-legged frogs (Adams et al. 2017b, p. 10228). 
Bullfrog presence is a positive predictor of Bd prevalence and load in 
foothill yellow-legged frogs (Adams et al. 2017a, p, 1). The Bd 
pathogen has been documented within all DPSs (Yap et al. 2018, p. 5, 
figure 1), and evidence of Bd prevalence suggests that Bd played a role 
in the precipitous decline of the foothill yellow-legged frog in 
southern California. Bd has been implicated in the decline of the 
foothill yellow-legged frog in both the Central Coast DPS and South 
Coast DPS (Adams et al. 2017b, p. 10224). Bd may also have sublethal 
effects on foothill yellow-legged frogs. Foothill yellow-legged frogs 
that tested positive for Bd had lower body mass to length ratios, 
although the frogs showed no other signs of infection (Lowe 2009, pp. 
180-181). Tadpole susceptibility experiments with other western anurans 
documented species-specific effects of Bd exposure such as tadpole 
lethargy (motionless at bottom of tank), disorientation, weak response 
to prodding, and increased incidence of tadpole mouthpart deformities 
(Blaustein et al. 2005, pp. 1464-1466).
    Parasitism of foothill yellow-legged frogs by the Eurasian copepod, 
Lernaea cyprinacea, is linked to malformations in tadpole and juvenile 
foothill yellow-legged frogs (Kupferberg et al. 2009a, p. 529). In 
addition to malformations, this parasite likely has other sublethal 
effects on foothill yellow-legged frogs, such as stunted growth 
(Kupferberg et al. 2009a, p. 529). Although direct foothill yellow-
legged frog mortality from this parasite has not been documented in the 
wild, copepod parasitism may be responsible for mortality of tadpoles 
in captivity (Kupferberg 2019, entire; Oakland Zoo 2019, p. 1; Rousser 
2019, entire). The changes predicted by climate change models (i.e., 
increased summer water temperatures and decreased daily discharge) may 
promote outbreaks of this parasite throughout the foothill yellow-
legged frog's range (Kupferberg et al. 2009a, p. 529).
    The water fungus (Saprolegnia sp.) causes egg mortality in 
amphibians of the Pacific Northwest (Blaustein et al. 1994, p. 251). 
Fungal infections of foothill yellow-legged frog egg masses, 
potentially from Saprolegnia but not confirmed, have been observed in 
the mainstem Trinity River (North Coast DPS) (Ashton et al. 1997, pp. 
13-14), in approximately 25 percent of egg masses during a study in the 
South Fork Eel River (North Coast DPS) (Kupferberg 1996a, p. 1337), and 
in 14 percent of egg masses during 2002 and nearly 50 percent of egg 
masses during 2003 in the Cresta reach of the North Fork Feather River 
(North Feather DPS) (GANDA 2004, p. 55). While fungal infections are 
not a major source of mortality for foothill yellow-legged frogs, this 
threat has had a strong effect in other amphibian populations 
(Blaustein et al. 1994, pp. 251-253).
Habitat Loss, Degradation, and Fragmentation
    Habitat loss, degradation, and fragmentation occurs throughout the 
species' range and is attributed to numerous factors including 
agricultural activities, mining, urbanization, roads, recreation, and 
wildfire.
    Agriculture/Pesticides: Agriculture is a source of threats to the 
foothill yellow-legged frog because of agriculture's role in habitat 
degradation, the contribution of pesticides and pollutants to the 
environment, and its role as a driver of other threats such as altered 
hydrology and spread of nonnative species (see figure 26 in the SSA 
report, Service 2021, p. 88). Agricultural land uses have been linked 
to declines in foothill yellow-legged frog populations due to the 
impacts described above (Davidson et al. 2002, p. 1597; Lind 2005, pp. 
19, 51, 62, table 2.2; CDFW 2019, p. 58). Foothill yellow-legged frog 
presence is negatively associated with agriculture within 5 km (3.1 mi) 
(Olson and Davis 2009, pp. 15, 22; Linnell and Davis 2021, not 
paginated, figures 6 and 7).
    The proximity of foothill yellow-legged frog habitat downwind of 
the San Joaquin Valley (greatest use of airborne pesticides) suggests 
that foothill yellow-legged frog declines in the South Sierra unit may 
be linked to agricultural pesticide use (Davidson et al. 2002, p. 1594; 
Davidson 2004, pp. 1900-1901; Bradford et al. 2011, p. 690). Water 
samples from low elevations in the Sierra Nevada have had 
concentrations of pesticides that were within the lethal range for 
foothill yellow-legged frogs (Bradford et al. 2011, p. 690). Foothill 
yellow-legged frog tadpoles are especially vulnerable to pesticides, 
especially if pesticide exposure occurs in the presence of other 
threats, such as competition or predation (Davidson et al. 2007, 
entire; Sparling and Fellers 2007, entire; Sparling and Fellers 2009, 
entire; Kerby and Sih 2015, entire). Impacts from pesticides include 
reduced body size, slower development rate, and increased time to 
metamorphosis as well as decreased development of natural anti-
microbial skin peptides (presumably a defense against the disease, 
chytridiomycosis) (Davidson et al. 2007, p. 1774; Sparling and Fellers 
2009, pp. 1698, 1701; Kerby and Sih 2015, pp. 255, 260).
    Trespass Cannabis Cultivation: Trespass cannabis cultivation 
(illegally establishing largescale cannabis farms) occurs throughout 
the species' range, but the North Coast (California), Central Coast, 
and South Coast DPSs may be most at risk from this threat (CDFW 2019b, 
pp. 61-62). These unregulated activities impact the foothill yellow-
legged frog by destroying or degrading habitat, increasing water 
diversion, increasing sedimentation, and introducing pesticides and 
other chemicals that reduce water quality and impact the species (Bauer 
et al. 2015, entire).
    Mining Activities: Mining activities, including aggregate, hard-
rock, and suction-dredge mining, are sources of

[[Page 73925]]

threats to the foothill yellow-legged frog habitat because of their 
role in habitat destruction and degradation, pollution, and expansion 
of nonnative species (Hayes et al. 2016, pp. 52-54; Service 2021, 
figure 29, p. 94). Hydraulic mining, although outlawed, has had and 
continues to have long-lasting legacy effects and is still affecting 
aquatic ecosystems in California, with the North Feather DPS and North 
Sierra DPS being the most impacted (Hayes et al. 2016, pp. 52-54; CDFW 
2019b, pp. 57-58). The immediate and legacy effects and extent of 
mining practices are outlined in Table 8 of the SSA report (Service 
2021, table 8, pp. 92-93), and include habitat destruction and 
alteration, sedimentation, changes in stream morphology, decreased 
stream heterogeneity, creation of ponded habitat (that supports 
nonnative species), decreased water quality, and contamination. A 
moratorium of suction-dredging in streams has currently been put in 
place for California. However, the State is currently developing new 
guidance and permitting processes for potentially reinitiating suction-
dredging activities (State Water Resources Control Board 2020, entire). 
Oregon has restricted suction-dredging in the foothill yellow-legged 
frog's range (National Genomics Center for Wildlife and Fish 
Conservation 2021, entire).
    Urbanization: Urbanization (development and roads) can affect 
foothill yellow-legged frogs and their habitat through direct mortality 
and from habitat destruction, degradation, and fragmentation. 
Urbanization can also contribute to increased occurrence of pesticides 
and pollutants being introduced to the environment and increases in 
other threats such as altered hydrology, introduction and spread of 
nonnative species, and assist in disease transmission (see figure 30 in 
the SSA report, Service 2021, p. 95). Conversion or alteration of 
natural habitats for urban land uses has been linked to declines in 
foothill yellow-legged frog populations (Davidson et al. 2002, p. 1597; 
Lind 2005, pp. 19, 51, 62, table 2.2). Foothill yellow-legged frog 
presence is negatively associated with cities and road density 
(Davidson et al. 2002, p. 1594; Olson and Davis 2009, p. 22). Increases 
in urbanization and roads have been reportedly associated with foothill 
yellow-legged frog extirpations in the South Coast DPS, possibly by 
facilitating the spread of Bd and nonnative species (Adams et al. 
2017b, p. 10227).
    Recreational Activities: Some recreational activities can affect 
foothill yellow-legged frogs in a variety of ways, depending on the 
region and type of recreation. Impacts from recreation can be 
localized, such as trampling or dislodging of egg masses, while others 
are greater in extent or contribute to other threats. These greater 
threats include off-highway vehicle use causing habitat degradation and 
increased sedimentation (Olson and Davis 2009, p. 23), nonnative 
sportfish stocking of smallmouth bass (see Predation) (ODFW 2009, pp. 
8, 11; CDFW 2019a, entire), and altered hydrology due to whitewater 
boating (Borisenko and Hayes 1999, pp. 18, 28; Kupferberg et al. 2012, 
p. 518). Some dam operations include planned, short pulse flows during 
the spring and summer to specifically provide recreation opportunities 
for whitewater boaters (Kupferberg et al. 2012, p. 518). As with other 
impacts associated with water management, the timing of these strong 
unseasonal flows has coincided with the foothill yellow-legged frog 
breeding and rearing season, leading to negative population-level 
impacts in the North Feather DPS (Kupferberg et al. 2012, pp. 518, 520-
521, figure 3b).
    Wildfire: Wildfire is a natural phenomenon throughout the range of 
the foothill yellow-legged frog, and its occurrence and severity are 
positively influenced by urbanization, roads, recreation, and the 
effects of climate change. The effects on foothill yellow-legged frogs 
from wildfire and its suppression are not well understood and have not 
been directly studied (Hayes et al. 2016, p. 35, table 6; CDFW 2019b, 
p. 71). The impacts of wildfire are also a function of the severity and 
intensity of the wildfire, which can be extremely variable across the 
landscape depending on topography and vegetation. Anecdotally, foothill 
yellow-legged frog populations have survived low- to moderate-severity 
wildfires (Lind et al. 2003, p. 27; CDFW 2019b, p. 71), and it is 
suspected that low-severity fires do not have adverse effects on the 
foothill yellow-legged frog (Olson and Davis 2009, p. 24). In fact, 
wildfires may benefit habitat quality by decreasing canopy cover and 
increasing habitat heterogeneity (Pilliod et al. 2003, pp. 171, 173; 
Olson and Davis 2009, p. 24). Direct mortality from scorching is 
unlikely, given the species' aquatic nature and the sightings of 
foothill yellow-legged frogs immediately after wildfires (CDFW 2019b, 
p. 71). In contrast, high-severity wildfires can greatly alter water 
and habitat quality, remove all vegetative canopy, and reduce habitat 
heterogeneity by burning vegetative and woody debris that foothill 
yellow-legged frogs use for shelter. Short- and long-term effects of 
severe wildfires include potentially harmful changes in water chemistry 
and increased erosion and sedimentation from flooding (CDFW 2019b, pp. 
71-72), which can destroy or degrade breeding habitat and interstitial 
spaces. Furthermore, the use of fire retardants and suppressants during 
wildland firefighting can affect amphibians by harming water quality 
and by direct toxicity to amphibians and their food sources (Pilliod et 
al. 2003, pp. 174-175; Service 2018, pp. 42-44). See the SSA report for 
additional information regarding trends and impacts of wildfire 
(Service 2021, section 7.9, pp. 100-109).
Effects of Climate Change
    The effects of climate change are already having statewide impacts 
in California and Oregon (Bedsworth et al. 2018, p. 13; Mote et al. 
2019, p. ii, summary). Overall trends in climate conditions across the 
foothill yellow-legged frog's range include increasing temperatures, 
greater proportion of precipitation falling as rain instead of snow, 
earlier snowmelt (influencing streamflow), and increased frequency, 
duration, and severity of extreme events such as droughts, heat waves, 
wildfires, and floods (OCCRI 2019, pp. 5-7, tables 2 and 3; Public 
Policy Institute of California 2020, not paginated). A rangewide study 
of occupancy found that foothill yellow-legged frog presence is 
negatively related to the frequency of dry years and to precipitation 
variability, suggesting that the species may already be declining due 
to the effects from climate change (Lind 2005, p. 20).
    Projected increases in temperature are likely to affect foothill 
yellow-legged frogs differently in different parts of the range. 
Warming temperatures are likely to have some positive effects in areas 
where stream temperatures are typically colder, allowing for greater 
foothill yellow-legged frog population growth rates and early life 
stage survival (Kupferberg et al. 2011a, p. 72; Rose et al. 2020, p. 
41). However, researchers observed an unexpected die-off (unknown 
cause) of late-stage tadpoles that coincided with maximum daily 
temperatures exceeding 25 degrees Celsius ([deg]C) (77 degrees 
Fahrenheit ([deg]F)) (Kupferberg et al. 2011a, pp. 14, 58; Catenazzi 
and Kupferberg 2018, pp. 43-44, figure 2). Temperatures greater than 
the preferred thermal range may also have lethal or sublethal effects 
on tadpoles and metamorphs from parasites (Kupferberg et al. 2009a, p. 
529; Kupferberg et al. 2011a, p. 15). There may be additional negative 
consequences to rising stream

[[Page 73926]]

temperatures, even where temperatures are currently cold. Increasing 
temperatures may facilitate colonization by nonnative species (Fuller 
et al. 2011, pp. 210-211; Kiernan et al. 2012, pp. 1480-1481). Bd 
prevalence in bullfrogs was also found to be greater when water 
temperature was warmer than 17 [deg]C (63 [deg]F) (Adams et al. 2017a, 
pp. 12-13).
    In California, a 25 to 100 percent increase in the frequency of 
extreme dry-to-wet precipitation events (such as that of the 2012-2016 
drought followed by the extremely wet winter of 2016-2017) is projected 
during the 21st century (Swain et al. 2018, p. 427). This information 
indicates that the threats of drought and extreme flood events may 
increase by 25 to 100 percent in California. Increased frequency of 
extreme heat events, drought, and extreme precipitation and floods 
events are also projected to increase in Oregon (OCCRI 2019, pp. 5, 6, 
13-14, tables 2 and 3). In order to assess future conditions, including 
future climatic conditions for the foothill yellow-legged frog, we 
developed a population viability analysis (PVA) (Rose et al. 2020, 
entire) that used climate and habitat change information consistent 
with current emission estimates such as those identified as 
Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 (see 
Population Viability Analysis, below).
    The projected changes in temperature, precipitation, and climate 
variability may exacerbate the effects of other threats on the foothill 
yellow-legged frog (Service 2021, figure 46, p. 11). The potential 
interactions (between climate change effects and other threats) that 
can negatively affect the foothill yellow-legged frog include:
     An increased risk to human safety from flooding and 
increased risk of water shortages may necessitate more hydrological 
alterations (e.g., dams, surface-water diversions, changes to water 
releases, and channel modifications). While the effect of climate 
change is only projected to increase surface water stress by up to 5 
percent in the Oregon portion of the North Coast DPS's range by mid-
century, projected increases range from 5 to 30 percent in California 
watersheds (Averyt et al. 2013, p. 7, figure 7). In California, 
climate-induced surface water stress is projected to increase the most 
in the South Sierra DPS and the least in the North Coast DPS (Averyt et 
al. 2013, p. 7, figure 7).
     Increased frequency of drought, decreased spring/summer 
streamflow, and warmer water temperature may benefit nonnative 
predators and competitors such as bullfrogs and nonnative fish (Brown 
and Ford 2002, pp. 332, 338-340, figure 3; Fuller et al. 2011, pp. 210-
211; Adams et al. 2017a, p. 13).
     Increased summer water temperatures and/or decreased daily 
stream discharge and other increases in climate variability are 
expected to increase copepod parasitism in foothill yellow-legged frogs 
(Kupferberg et al. 2009a, p. 529) or exacerbate the effects of disease 
outbreaks (Raffel et al. 2013, p. 147; Adams et al. 2017b, p. 10228).
     Observed and projected trends toward warmer and drier 
wildfire seasons in the western United States are likely to continue 
the trend toward higher-severity wildfires and larger burn areas (Parks 
and Abatzoglou 2020, pp. 1, 5-6). This would result in additional loss, 
degradation, fragmentation, and alteration of habitat, and secondary 
impacts from increased sedimentation and flooding for the foothill 
yellow-legged frog across its range.
Competing Conservation Interests
    Many of the conservation activities that support native salmonid 
fishes (e.g., natural flow management, prevention of sedimentation) 
have positive influences on foothill yellow-legged frog habitat, 
connectivity, and juvenile and adult survival (Service 2021, section 
7.12, figure 45, p. 113). However, some measures that are taken to 
improve habitat for cold-water salmonid fishes reduce habitat quality 
for the foothill yellow-legged frog by decreasing stream temperature 
and increasing tree canopy cover over streams. One of the management 
techniques used to support salmonid recruitment is to release high 
volumes of cold water from dams in the spring (to trigger spawning runs 
or to flush smolts out to the ocean) (Kupferberg 1996a, p. 1342; 
Kiernan et al. 2012, p. 1474). The timing of such flow events can 
negatively affect foothill yellow-legged frog breeding and recruitment 
(Kupferberg 1996a, pp. 1336-1337, 1342).
Current and Future Condition Analysis
    In our analysis of the current and future condition, we assessed 
resiliency for each DPS of the foothill yellow-legged frog by 
evaluating the health and number of metapopulations for each DPS. A 
healthy metapopulation is defined in terms of its abundance, level of 
reproduction and recruitment, juvenile and adult survival, and 
connectivity between populations. To assess the current representation 
for the foothill yellow-legged frog, we considered the current 
diversity of ecological conditions and the genetic makeup of each DPS 
as a proxy for the DPS's adaptive capacity. Redundancy for the foothill 
yellow-legged frog was measured by the quantity and spatial 
distribution of resilient metapopulations across each DPS's range. 
Generally speaking, the greater the number of healthy metapopulations 
that are distributed (and connected) across the landscape, the greater 
the DPS's ability to withstand catastrophic events and, thus, the 
greater the DPS's overall viability.
Population Structure
    Foothill yellow-legged frog distributions and movements across the 
species' range and within each DPS exhibit the characteristics of 
metapopulations (Lind 2005, p. 49; Kupferberg et al. 2009b, p. 132). A 
metapopulation consists of a network of spatially separated population 
units, or subpopulations, that interact at some level. Subpopulations 
are subject to periodic extirpation from demographic or environmental 
stochasticity, but then are naturally repopulated via colonization from 
nearby subpopulations. Numerous metapopulations may occur within a 
single stream reach or watershed depending on whether the 
subpopulations are interacting with each other. Each DPS is made up of 
numerous metapopulations. In our analysis for determining the range of 
each DPS, we considered this metapopulation structure when determining 
whether certain populations or segments interacted with each other and 
helped define boundaries for the DPSs, especially where some other 
natural or manmade barrier was not evident.
Historical Distribution
    The historical distribution, as identified once the species was 
established as a single taxon of the foothill yellow-legged frog 
(Zweifel 1955, pp. 210, 273), extended from west of the crest of the 
Cascade Mountains in the Willamette River drainage to the coast in 
Oregon, south through the Coast Range to Los Angeles County, 
California, and down the Sierra Nevada foothills and mountains to 5,000 
feet (1,524 meters) (CDFW 2019, pp. 7-8; Service 2021, p. 16, Figure 
2). Isolated populations or individuals had been identified in the 
Sacramento (at Sutter Buttes) and Central Valleys (Mokelumne River 
drainage) of California and in Baja California Norte, Mexico (San Pedro 
Martir), but these locations were either isolated individuals or have 
not been found again (Loomis 1965, pp. 78-79; Stebbins 2003, pp. 231-
233, 479). Based on our knowledge of foothill yellow-

[[Page 73927]]

legged frog genetic divergence at much smaller spatial scales of 
isolation (McCartney-Melstad et al. 2018, p. 121; Peek 2018, p. 76), 
the distant Mexico population once identified as foothill yellow-legged 
frog, now considered extirpated, most likely was a different taxon.
    In Oregon, past impacts from timber operations resulting in stream 
alteration have reduced the historical range of the species in the 
Willamette Valley and in the southeast portion (portions of Jackson 
County) of the State (Olson and Davis 2009, p. 9-11). In California, 
the historical range has also been reduced most likely from 
hydrological alteration of habitat associated with water management 
(Lind 2005, pp. 65, 68, figures 2.1 and 2.4).
Current Distribution, Occupancy, Abundance, and Population Trends
    The current distribution of the foothill yellow-legged frog 
generally follows the historical distribution of the species except 
with range contractions in the southern and, to a lesser extent, 
northern parts of the species' range as discussed above. Within areas 
currently occupied, foothill yellow-legged frog distribution is 
currently in a declining trend in several parts of the species' range 
with the species having disappeared from more than half of its 
historically-occupied locations (Lind 2005, pp. 38, 61, table 2.1). 
Some areas in Oregon, especially in the northern and northwestern 
portion of the species' range, have shown declines; however, recent 
survey efforts have identified additional populations of the species in 
some of these areas (National Genomics Center for Wildlife and Fish 
Conservation 2021, entire).
    There has not been any rangewide occupancy or population abundance 
survey effort for the species, and some areas are more heavily surveyed 
than others. Because of this variation in the available data, we use 
presence in stream segments as an indicator of occupancy and spatial 
connectivity of populations. In our review of occupancy, distribution, 
and abundance, we used information from the California Natural 
Diversity Database (CNDDB 2020, foothill yellow-legged frog 
information) and other survey information obtained from Federal and 
other academic and private resource entities throughout the species' 
range. The factors we analyzed to determine the condition of a 
population are (1) spatial and temporal trends in occupancy and reports 
of population abundance where available, (2) connectivity and isolation 
among occupied areas, (3) modeled risk of population decline that 
incorporates demographic and environmental information, and (4) status 
of threats and their effects (see chapter 8 of the SSA report, Service 
2021, pp. 122-166).
    Foothill yellow-legged frog occupancy varies widely among the DPSs, 
with generally greater occupancy in the northern half of the range. The 
North Sierra DPS has the greatest proportion of presumed occupied 
stream segments (relative to the number of potential stream segments), 
followed by the North Coast (in California) and North Feather DPSs. 
Proportions of presumed occupied stream segments were much lower in the 
rest of the DPSs with the South Coast DPS having the lowest proportion 
of presumed occupied segments, followed by the South Sierra DPS (see 
table 10 in the SSA report, Service 2021, p. 125).
    Based on historical and current occurrence data (Element 
Occurrences) for California (CDFW 2020, entire), 67-70 percent of all 
known occurrence locations are presumed to be occupied by the foothill 
yellow-legged frog in the North Coast DPS (in California), North 
Feather DPS, and North Sierra DPS (Service 2021, Table 10, p. 125). In 
contrast, less than 45 percent of known occurrence locations are 
presumed occupied in the South Sierra DPS, Central Coast DPS, and South 
Coast DPS (Service 2021, Table 10, p. 125). Based on patterns of 
current occupancy by decade of most recent detections (Service 2021, 
figures 47-53, pp. 127-139), occupied area appears to be declining in 
parts of each of the DPSs but less so in the northern California and 
southern Oregon portions of the taxon's range (North Coast DPS). There 
are large regions in both the northern part of the range (northern 
Oregon) (North Coast DPS in Oregon) and in the southern half of the 
species' range (South Sierra DPS, Central Coast DPS, and South Coast 
DPS) that have not had any reported observations of foothill yellow-
legged frogs for two or more decades. Foothill yellow-legged frogs are 
mostly extirpated in the South Coast DPS and currently occur only in 
two streams. Table 1 below identifies the percentage of occurrence 
records considered occupied (2000-2020) in California. Comparable 
Element Occurrence data are not available for the North Coast Oregon 
analysis unit. For our analysis of Oregon, we looked to other sources 
of information on occurrences (Service 2021, pp. 127-144).

Table 1--Percentage of Extant Occurrence Records (CDFW 2020) by Analysis
                                  Unit
------------------------------------------------------------------------
              Analysis unit                     2000-2020 (percent)
------------------------------------------------------------------------
North Coast, Oregon......................  Not Available.
North Coast, California..................  67.
North Feather............................  70.
North Sierra.............................  70.
South Sierra.............................  43.
Central Coast............................  42.
South Coast..............................  8.
------------------------------------------------------------------------

Population Viability Analysis
    In addition to our assessments of occupancy, abundance, and trends, 
using occurrence information, we worked with USGS researchers to 
complete a rangewide population viability analysis (PVA) for the 
foothill yellow-legged frog (Rose et al. 2020, entire). We used the 
information from the PVA to inform both the species' current condition 
(Service 2021, chapter 8, pp. 122-166) and potential future condition 
(Service 2021, chapter 9, pp. 167-193). The methods and information 
used for developing the models used in the PVA are described in section 
8.4 of the SSA report (Service 2021, pp. 146-152). The results of the 
PVA focus on identifying patterns in risk attributed to areas having a 
greater than or equal to 50 percent decline within and between analysis 
units and characterize this as the `risk of decline.'
    The `risk of decline' results from the PVA reflect many of the 
geographical patterns that we described above for occupancy data 
(Service 2021, section 8.2, pp. 123-139). A summary of the PVA results 
for the current condition of foothill yellow-legged frog populations 
within the boundaries of the DPSs combined with our analysis of 
occupancy information is discussed below.
    The North Sierra DPS has both the lowest average relative risk of 
decline and the greatest proportion of presumed occupied stream 
segments (relative to stream segments that have the potential to be 
occupied). The North Feather DPS has a medium-high average relative 
risk of decline and an intermediate proportion of occupied stream 
segments (relative to potential stream segments). Within the North 
Coast DPS, stream segments in northern California and southwestern 
Oregon have lower risks of decline, compared to streams near the San 
Francisco Bay area and the northern and eastern extents of the species' 
range in Oregon. The southern analysis units (Central Coast DPS, South 
Coast DPS, and South Sierra DPS) exhibit the strongest patterns of 
declining occupancy, with all stream segments

[[Page 73928]]

within each DPS having either a medium or high relative risk of 
decline.
    Chapter 9 of the SSA report (Service 2021, pp. 167-193) discusses 
the potential change in magnitude and extent of threats and the 
species' response to those threats into the future. We have determined 
that the effects of climate change and its impact on increasing 
temperatures, changes to precipitation and hydrology, and influence on 
wildfire and drought, as well as the continued regulated flows from 
managed streams, will drive threats on the species and affect its 
status into the future. The timeframe of our analysis for these threats 
is approximately 40 years. This period represents our best 
understanding of the projected future environmental conditions related 
to threats associated with climate change that would impact the species 
(increasing temperatures, greater proportion of precipitation falling 
as rain instead of snow, earlier snowmelt (influencing streamflow), and 
increased frequency, duration, and severity of extreme events such as 
droughts, heat waves, wildfires, and floods). The 40-year timeframe was 
also used in our PVA as part of its analysis on determining risk for 
the species into the future (Rose et al. 2020, entire). Although we 
possess climate and habitat change projections that go out beyond 40 
years, there is greater uncertainty between these model projections in 
the latter half of the 21st century and how the effects of the modeled 
changes will affect the species' response when projected past 40 years. 
Accordingly, we determined that the foreseeable future extends only 40 
years for the purpose of this analysis and we rely upon projections out 
to approximately 2060 for predicting changes in the species' 
conditions. This timeframe allows us to be more confident in assessing 
the impact of climate and habitat changes on the species. Therefore, 
based on the available climate and modeling projections and information 
we have on the species, we have determined 2060 as the foreseeable 
future timeframe for the foothill yellow-legged frog.
    Our assessment of future condition interprets the effects that the 
future changes to threats would potentially have on foothill yellow-
legged frog resiliency, representation, and redundancy. In order to 
accomplish our review, three plausible future scenarios were considered 
and each DPS's future resiliency, redundancy, and representation under 
each scenario was assessed. As discussed above, we used information 
from a PVA (Rose et al. 2020, pp. 22-27) to assist us in determining 
the potential condition of foothill yellow-frog populations into the 
future. Although there are an infinite number of possible future 
scenarios, the chosen scenarios (i.e., lower change scenario, mean 
change scenario, and higher change scenario) reflect a range of 
reasonable scenarios based on the current understanding of climate 
change models, threats, and foothill yellow-legged frog ecology. The 
environmental conditions in each future scenario are plausible in that 
they are not meant to represent the lowest and highest projections of 
what is possible. Rather, the lower change and higher change scenarios 
are at the lower and upper ends of confidence intervals from climate 
change projections, land cover models, and stream temperature models 
(Rose et al. 2020, pp. 22-23). Environmental conditions for the three 
future scenarios are based on published studies that used ensembles of 
global climate models (Isaak et al. 2017, p. 9188; Swain et al. 2018, 
p. 427; Sleeter et al. 2019, p. 3336). For the projections of spatially 
explicit covariates (i.e., land cover and stream temperature), 
downscaled regional climate model data were used (Isaak et al. 2017, p. 
9186; Sleeter et al. 2019, p. 3339). The information from these studies 
reflects the best scientific and commercial information available for 
projections of land cover (Sleeter et al. 2019; Sleeter and Kreitler 
2020, unpublished data), stream temperature (Isaak et al. 2017), and 
climate variability (Swain et al. 2018) within the range of the 
foothill yellow-legged frog.
    Descriptions of each scenario and the anticipated effects of each 
scenario on resiliency, representation, and redundancy for each 
foothill yellow-legged frog DPS is in the SSA report (Service 2021, 
Table 17, sections 9.3-9.5, pp. 171, 174-193) and is summarized below.
Resiliency
    Resiliency is having sufficiently robust populations for the 
species to withstand stochastic events (i.e., events arising from 
random factors). For the foothill yellow-legged frog, we determined 
that resiliency is a function of metapopulation health and the 
distribution and connectivity among metapopulations and subpopulations. 
To determine if foothill yellow-legged frog populations were resilient, 
we first assessed spatial and temporal trends in occupancy and 
abundance. We then assessed structural and functional connectivity 
among occupied areas. We also evaluated results from a study that 
modeled the risk of >=50 percent decline in occupied stream segments 
using demographic and environmental information. Finally, we related 
our results to information from scientific literature, reports, and 
species experts. Table 2 below summarizes the current condition and 
future conditions of resiliency for each of the foothill yellow-legged 
frog DPSs. In the SSA report and the table below, we split the North 
Coast DPS into a California and an Oregon analysis unit. These two 
analysis units are later combined for determination of the status of 
this DPS as a whole. The current condition column reflects the current 
resiliency of the analysis unit. The current resiliency of each DPS was 
characterized as having an intact, reduced, substantially reduced, or 
extensively reduced condition. Under each future scenario, we assessed 
how the following resiliency measures would change from current 
condition: (1) Occupancy and abundance, (2) connectivity, (3) modeled 
risk of population decline, and (4) status of threats. Because changes 
to environmental conditions under the future scenarios were reflected 
by environmental covariates in the PVA (see Service 2021, section 9.2 
(Scenarios); Table 17), we were able to forecast the magnitudes of 
changes in resiliency by comparing the modeled risk of decline (Rose et 
al. 2020, entire) under current conditions to modeled risk under the 
three future scenarios. The lower, mean, and higher change scenario 
columns represent any changes from each DPS's current resiliency. For 
this analysis, ``functional extirpation'' is defined as such extensive 
reduction in condition that extirpation of the entire unit is likely to 
eventually occur as remnant populations experience normal environmental 
and demographic fluctuations. For additional detail on current and 
future conditions of the DPSs, see the SSA report (Service 2021, 
chapters 8 and 9, pp. 122-193).

[[Page 73929]]



                   Table 2--Resiliency of the Seven Foothill Yellow-Legged Frog Analysis Units
----------------------------------------------------------------------------------------------------------------
                                                         Lower change         Mean change        Higher change
         Analysis unit           Current condition         scenario            scenario            scenario
----------------------------------------------------------------------------------------------------------------
North Coast DPS (Oregon)......  Intact Resiliency..  Slightly reduced     Slightly reduced    Markedly reduced
                                                      from current.        from current.       from current.
North Coast DPS (California)..  Intact Resiliency..  Slightly reduced     Markedly reduced    Greatly reduced
                                                      from current.        from current.       from current.
                                                                                               Risk of
                                                                                               functional
                                                                                               extirpation.
North Feather DPS.............  Reduced Resiliency.  No change..........  Markedly reduced    Greatly reduced
                                                                           from current.       from current.
                                                                           Risk of             Risk of
                                                                           functional          functional
                                                                           extirpation.        extirpation or
                                                                                               extirpation.
North Sierra DPS..............  Intact Resiliency..  Slightly reduced     Markedly reduced    Greatly reduced
                                                      from current.        from current.       from current.
South Sierra DPS..............  Substantially        Slightly reduced     Markedly reduced    Greatly reduced
                                 Reduced Resiliency.  from current.        from current.       from current.
                                                                           Risk of             Risk of
                                                                           functional          functional
                                                                           extirpation or      extirpation or
                                                                           extirpation.        extirpation.
Central Coast DPS.............  Substantially        Slightly reduced     Markedly reduced    Greatly reduced
                                 Reduced Resiliency.  from current.        from current.       from current.
                                                                           Risk of             Risk of
                                                                           functional          functional
                                                                           extirpation or      extirpation or
                                                                           extirpation.        extirpation.
South Coast DPS...............  Extensively Reduced  Slightly reduced     Markedly reduced    Greatly reduced
                                 Resiliency.          from current. Risk   from current.       from current.
                                                      of extirpation.      Risk of             Risk of
                                                                           extirpation.        extirpation.
----------------------------------------------------------------------------------------------------------------

Representation
    Representation describes the ability of a species to adapt to 
changing environmental conditions. This includes both near-term and 
long-term changes in its physical (e.g., climate conditions, habitat 
conditions, habitat structure, etc.) and biological (e.g., pathogens, 
competitors, predators, etc.) environments. This ability of a species 
to adapt to these changes is often referred to as ``adaptive 
capacity.'' To assess the current condition of representation for the 
foothill yellow-legged frog, we considered the current diversity of 
ecological conditions and of genetic material throughout the range of 
the species.
    There are considerable ranges of ecological conditions under which 
foothill yellow-legged frogs occur. As discussed in the SSA Report 
(Service 2021, Section 2.7 and CHAPTER 3), there are substantial 
differences in latitude, elevation, precipitation, average temperature, 
and vegetative community across the species' range. Parts of the 
foothill yellow-legged frog range also differ in terms of species 
composition and in hydrology (rain-fed versus snow-fed systems). 
Exemplary of these different ecological conditions, foothill yellow-
legged frog tadpoles from snow-fed Sierra Nevada populations have 
higher intrinsic growth rates than tadpoles from rain-fed coastal 
populations, likely due to their constraint to a shorter rearing season 
in the Sierra Nevada (Catenazzi and Kupferberg 2017, pp. 1255, 1260-
1261).
    As described in the SSA report (Service 2021, Section 2.6), two 
rangewide assessments of foothill yellow-legged frog genomic datasets 
revealed that this taxon is extremely differentiated following 
biogeographical boundaries (McCartney-Melstad et al. 2018, p. 112; Peek 
2018, p. 76). The clades that are most genetically divergent (i.e., 
South Sierra, Central Coast, and South Coast clades), and thus could 
contribute most to the overall adaptive capacity of this taxon 
(McCartney-Melstad et al. 2018, p. 120; Peek 2018, p. 77), are also the 
clades with the lowest levels of population resiliency. The South 
Sierra and Central Coast clades have substantially reduced resiliency 
and the South Coast clade has extensively reduced resiliency (SSA 
Report (Service 2021, Section 8.5)). The reduced resiliency in these 
clades, means that the foothill yellow-legged frog is especially 
vulnerable to loss of this genetic diversity. The Central Coast and 
South Coast clades are the most genetically divergent, indicating that 
a significant amount of the taxon's overall genetic diversity would be 
lost if either clade were extirpated. The Central Coast and South Coast 
clades are also ecologically unique because they have lower annual 
precipitation and higher mean annual temperatures than elsewhere in the 
range of the species (PRISM Climate Group 2012, 30-year climate 
dataset; Table 3) and the region hosts the highest freshwater endemism 
of anywhere in the species' California range (Howard et al. 2013, p. 
5).
    While not as at risk of extirpation, the northern Sierra clades 
(i.e., North Feather and North Sierra clades) might also have unique 
adaptive potential in the face of climate change because of their 
admixture history and intermediacy to the South Sierra and North Coast 
clades (McCartney-Melstad et al. 2018, p. 121). The genetic clade that 
is comprised of the two North Coast units is also genetically valuable 
to the foothill yellow-legged frog because it contains the greatest 
genetic diversity and is the only part of the range that shows a 
trajectory of increasing genetic diversity (McCartney-Melstad et al. 
2018, pp. 120-121; Peek 2018, p. 74). The North Coast clade also 
potentially provides connectivity and a large latitudinal gradient for 
responding to the effects of climate change.
    While the foothill yellow-legged frog clearly has a range of 
genetically divergent populations, it has likely already lost a lot of 
diversity due to large extirpations in the southern analysis units. The 
species is also at risk of further losses amidst trends toward 
decreasing occupancy and decreasing connectivity. The foothill yellow-
legged frog is exhibiting an overall trend of decreasing genetic 
diversity in spite of the trend of increasing genetic diversity in the 
North Coast clade (McCartney-Melstad et al. 2018, pp. 120-121; Peek 
2018, p. 74).
    The trend of decreasing genetic diversity in the foothill yellow-
legged frog may be leading to losses in adaptive capacity (i.e., 
ability to adapt to change). Loss of adaptive capacity lowers the 
species' viability because the decrease in ability to adapt to change 
increases extinction risk in the face of future changes. For foothill 
yellow-legged frog conservation, McCartney-Melstad et al. (2018, p. 
122) strongly recommended that each of the major genetic groups be 
managed as independent recovery units. Peek (2018, p. 77) also 
recommended that conservation actions should prioritize protecting 
foothill yellow-legged frogs in the Central Coast, South Coast, and 
South Sierra clades because they are simultaneously the most distinct, 
divergent, and at-risk populations.
Redundancy
    Redundancy describes the ability of a species to withstand 
catastrophic events. To assess redundancy for each analysis unit, we 
considered the (1) quantity of occupied stream segments (proxy for 
subpopulations) (SSA Report (Service 2021,Table 10)), (2) spatial 
distribution of occupied stream

[[Page 73930]]

segments (SSA Report (Service 2021, Figure 55)), and (3) population 
level factors such as connectivity, relative risk of decline, and level 
of threats. These factors were assessed in terms of their potential 
influence on the ability of foothill yellow-legged frog metapopulations 
to survive and recover after a plausible catastrophic event. For 
example, isolation of occupied stream segments or lack of functional 
connectivity in an analysis unit, could prevent recolonization of 
extirpated areas after a massive die-off or temporary habitat 
destruction.
    At the analysis unit scale of redundancy, long-term viability after 
a catastrophic event would likely be possible in the North Coast clade 
(North Coast California and North Coast Oregon units) and might be 
possible in the North Sierra clade. In the North Coast clade, there are 
large numbers of occupied streams and there are numerous occupied 
stream segments that both are in the low risk of decline category and 
are distributed widely across the geographical area (SSA Report 
(Service 2021, Figure 55)). Furthermore, resiliency is intact in both 
of the two analysis units that comprise this clade. Resiliency is also 
intact in the North Sierra clade because there are numerous occupied 
stream segments that both are in the low risk of decline category and 
are distributed widely across the geographical area (SSA Report 
(Service 2021, Figure 55)). However, the North Sierra clade has less 
redundancy than the North Coast clade because the North Sierra clade is 
small in size and has poor functional connectivity, which could prevent 
recolonization after catastrophic events.
    The North Feather DPS occupies a relatively small area and several 
streams or occurrences have been extirpated from past impacts (eastern 
portion of range, southwestern area near Lake Oroville, and some 
occurrences in northern Butte County) (CDFW 2020, dataset, entire; 
Service 2021, figure 49, p. 131). The North Feather DPS also has the 
highest average relative risk of population decline with only 16 (15 
percent) of the 109 analyzed stream segments in the low risk category 
and 34 stream segments (31 percent) in the high risk category. Overall 
abundance of foothill yellow-legged frogs for the North Feather DPS is 
largely unknown, but egg mass densities are very low in the two 
regulated stream reaches that have long-term monitoring (Rose et al. 
2020, pp. 63-64, table 1). For example, sections of the Cresta reach of 
the North Feather River that historically had relatively high numbers 
of foothill yellow-legged frog egg masses did not have egg masses or 
were extremely reduced for several years (2006-2017) (CDFW 2019, p. 31; 
Dillingham 2019, p. 7). As a result, redundancy is limited in the North 
Feather DPS. The North Feather DPS is not only the smallest clade, but 
its occupied stream segments are not well-distributed over the 
geographical area (SSA Report (Service 2021, Figure 55)). The extant 
North Feather populations occupy an area small enough that a large 
catastrophic event, such as a high-severity wildfire or drought, could 
result in functional extirpation. Furthermore, the North Feather DPS 
has reduced resiliency because of poor occupancy and relatively high 
risk of population decline.
    Redundancy is poor in the South Sierra and Central Coast clades. 
Both the South Sierra and Central Coast clades have substantially 
reduced resiliency because of poor occupancy, poor connectivity, 
relatively high risk of decline, and substantial threats. A single 
catastrophic event would be unlikely to extirpate the entirety of 
either unit, but the patchy distribution of occurrences (SSA Report 
(Service 2021, Figure 55)) and limited connectivity would make it 
extremely unlikely that extirpated areas would be recolonized 
naturally.
    Redundancy within the South Coast clade is nearly zero. Not only is 
the resiliency in this clade extensively reduced, but there are only 
two known populations (SSA Report (Service 2021, Section 8.2)) in the 
South Coast clade. These two populations (comprised of seven stream 
segments) are also very close in proximity (SSA Report (Service 2021, 
Figure 55)). These streams are located close to one another, but the 
foothill yellow-legged frog populations within them appear to have lost 
genetic connectivity. Although the stream flows are not regulated by 
dams, the risk of population decline continues to be medium or high 
under current conditions due to the combination of threats identified 
above altering habitat and impacting the DPS. Furthermore, the close 
proximity of the stream segments to each other makes the South Coast 
DPS especially vulnerable to extirpation from a single catastrophic 
event.
Overall Current and Future Condition
    As discussed above, we used the information from the PVA to inform 
both the species' current condition (Service 2021, chapter 8, pp. 122-
166) and potential future condition (Service 2021, chapter 9, pp. 167-
193). The PVA assessed how the following measures would change from 
current condition: (1) Occupancy and abundance, (2) connectivity, (3) 
modeled risk of population decline, and (4) status of threats under 
each future scenario. Because changes to environmental conditions under 
the future scenarios were reflected by environmental covariates in the 
PVA (see Service 2021, section 9.2 (Scenarios); Table 17), we were able 
to forecast the magnitudes of changes in resiliency by comparing the 
modeled risk of decline (Rose et al. 2020, entire) under current 
conditions to modeled risk under the three future scenarios. The 
results of the analysis showed that the average risk of population 
decline for each analysis unit increased under the three future 
scenarios (Rose et al. 2020, p. 39). Under current conditions and all 
future scenarios, the average relative risk of decline was highest in 
the South Sierra and Central Coast units and was lowest in the North 
Coast Oregon, North Coast California, and North Sierra units (Table 3 
below and Service 2021, Tables 18 and 19). Under the lower change 
scenario, decreases in resiliency, compared to current conditions, were 
small in most analysis units. However, decreases in resiliency were 
more dramatic under the mean and higher change scenarios. These 
dramatic declines in resiliency put several analysis units at risk of 
unit-wide extirpation or functional extirpation (i.e., such extensive 
reduction in condition that extirpation of the entire unit is likely to 
eventually occur as remnant populations experience normal environmental 
and demographic fluctuations) under the mean and higher change 
scenarios (SSA Report (Service 2021, Table 19)). One of the analysis 
units (South Coast unit) is at risk of unit-wide extirpation under all 
three of the future scenarios.

[[Page 73931]]



           Table 3--Relative Risk of Decline Summary for Current Condition and Three Future Scenarios
----------------------------------------------------------------------------------------------------------------
                                                                  Risk of decline
                                 -------------------------------------------------------------------------------
          Analysis unit                                  Lower change         Mean change        Higher change
                                   Current condition       scenario            scenario            scenario
----------------------------------------------------------------------------------------------------------------
North Coast Oregon..............  Low...............  Medium............  Medium............  Medium.
North Coast California..........  Medium............  Medium............  Medium............  Medium.
North Feather...................  Medium............  Medium............  High..............  High.
North Sierra....................  Low...............  Low...............  Medium............  Medium.
South Sierra....................  Medium............  High..............  High..............  High.
Central Coast...................  Medium............  Medium............  High..............  High.
South Coast.....................  Medium............  Medium............  Medium............  High.
----------------------------------------------------------------------------------------------------------------

Conservation Efforts and Regulatory Mechanisms
    Several initiatives and conservation efforts are in place and being 
implemented for foothill yellow-legged frog conservation including 
measures for rearing (headstarting), nonnative species removal, 
development of reintroduction feasibility studies, and habitat 
conservation planning for the species (Service 2021, table 9, pp. 117-
120). Headstarting (hatching eggs and rearing into releasable frogs) 
has been started on the North Feather River. The program has just been 
started and the extent from headstarting is limited to a portion of the 
range of the North Feather DPS. Also benefitting the species (through 
regulatory protection) is the decision by the California Fish and Game 
Commission to list five foothill yellow-legged frog genetic clades 
(referred to as analysis units in this document) under the California 
Endangered Species Act. In February 2020, the California Fish and Game 
Commission adopted the findings of the CDFW to list the South Coast, 
Central Coast, and South Sierra clades as endangered and list the North 
Feather and North Sierra clades as threatened under the California 
Endangered Species Act (Commission 2020, p. 1). Another regulatory 
benefit that applies to breeding and rearing habitat is the 2009 
moratorium on suction-dredge mining in California. However, benefits to 
the foothill yellow-legged frog from the moratorium have not been 
studied, and permitting processes are in development so that the 
moratorium may be lifted (State Water Resources Control Board 2020, 
entire).
    The foothill yellow-legged frog is listed as a sensitive species by 
the BLM and the Forest Service under their Sensitive Species program. 
These agencies define sensitive species as those species that require 
special management consideration to promote their conservation and 
reduce the likelihood and need for future listing under the Act. Any 
actions conducted by the Forest Service or BLM would need to take into 
consideration impacts to sensitive species and, if possible, implement 
best management practices to limit impacts to the species or its 
habitat. In addition, the species in northern portions of California 
and the species' range in Oregon on National Forest or BLM lands 
currently receive protection through conservation measures and best 
management practices under the Northwest Forest Plan's Survey and 
Manage program (USDA-USDOI 2001, entire). These measures reduce or 
eliminate impacts to habitat for the foothill yellow-legged frog and 
areas occupied by the species during road construction and maintenance 
activities as well as any vegetation management actions which assist in 
the reduction of threats associated with wildfire on BLM and Forest 
Service lands.
    The Federal Energy Regulatory Commission (FERC) issues licenses for 
the operation of nonfederal hydropower projects. Within the range of 
the foothill yellow-legged frog, numerous hydropower projects require 
FERC licensing to operate. Part of the licensing process includes 
consideration of recommendations for the protection of fish and 
wildlife. Some FERC license requirements have included measures to help 
protect and conserve foothill yellow-legged frogs including actions 
such as collection of data, implementation of modified flow regimes to 
mimic more natural conditions, and other standard best management 
practices.
    Two joint Federal and State habitat conservation plans (HCPs) and 
California State natural community conservation plans (NCCPs) (Santa 
Clara Valley HCP/NCCP and East Contra Costa HCP/NCCP) have been 
approved and implemented for the foothill yellow-legged frog as a 
covered species and assist in local population and habitat conservation 
(Jones & Stokes 2006, entire; ICF International 2012, entire). Both 
HCP/NCCPs are in the northern portion of the Central Coast DPS's range. 
Another Federal HCP has been issued to the Humboldt Redwood (formerly 
Pacific Lumber) Company. The Humboldt Redwood Company (HRC) HCP covers 
areas within the range of the North Coast DPS in Humboldt County and 
includes adaptive management strategies designed to maintain viability 
in populations of foothill yellow-legged frogs and other covered 
aquatic herpetofauna (HRC 2015, entire).
    Due to the limited nature of existing conservation efforts and no 
rangewide planning or coordination, the current conservation efforts 
are localized. In addition, several ongoing efforts are preliminary 
steps to on-the-ground conservation (e.g., feasibility research) and 
other efforts have not had enough time to verify long-term success 
(e.g., population headstarting) or determine if and how the condition 
of a foothill yellow-legged frog population may have improved (e.g., 
bullfrog removal) (Service 2021, section 7.15, pp. 116-121). Therefore, 
large scale conservation efforts are not known to be currently 
outweighing any of the threats described above at the species or DPS 
level, but may reduce some effects at the individual or smaller 
localized population level.

Determination of Status for the Foothill Yellow-Legged Frog

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species meets the definition of an ``endangered species'' or 
a ``threatened species.'' The Act defines an ``endangered species'' as 
a species in danger of extinction throughout all or a significant 
portion of its range, and a threatened species as a species likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range. The Act requires that we 
determine whether a species meets the definition of an ``endangered 
species'' or a ``threatened species'' because of any of the following 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B)

[[Page 73932]]

overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence.
    In determining potential future threats facing the six DPSs, we 
evaluated various future conditions based on projections of changes in 
threats. Our timeframe for review looked out approximately 40 years 
based on the effects of climate change and information developed for 
the PVA. This was our timeframe for our threats analysis of future 
conditions for the six DPS to determine if they were likely to become 
endangered within the foreseeable future (i.e., if they meet the Act's 
definition of ``threatened species'') throughout their ranges.

Status of the South Sierra DPS and the South Coast DPS of the Foothill 
Yellow-Legged Frog Throughout All of Their Ranges

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the South Sierra and South Coast DPSs of the foothill yellow-legged 
frog and their habitat. Below we summarize our assessment of status of 
the South Sierra DPS and South Coast DPS under the Act.
    South Sierra DPS: Threats are numerous and severe for the South 
Sierra DPS and include altered hydrology (Factor A), agriculture 
(including airborne pesticide drift) (Factor A), illegal cannabis 
cultivation (Factor A), predation by nonnative species (Factor C), 
disease and parasites (Factor C), mining (Factor A), urbanization 
(including development and roads (Factor A), recreation (Factor E), 
severe wildfire (Factor A), drought (Factor E), extreme flooding 
(Factor E), the effects of climate change (e.g., increased 
temperatures, variability in precipitation events, increased drought 
frequency) (Factor E), and inadequacy of regulatory mechanisms (Factor 
D). After evaluating threats to the DPS and assessing the cumulative 
effect of the threats under the Act's section 4(a)(1) factors, we 
conclude that under current conditions, resiliency, redundancy and 
representation are substantially reduced due to existing range 
contractions and the DPS's extensive extirpations and patchy 
distribution within and between stream segments. Both structural and 
functional connectivity are also poor in the South Sierra DPS. While 
exact abundances are largely unknown, populations within the DPS are 
relatively small and isolated and are impacted by numerous threats that 
are of such extent and magnitude that they are making the South Sierra 
DPS currently more susceptible to loss from stochastic or catastrophic 
events. The South Sierra DPS also has a high average risk of decline 
with no stream segments in lower risk categories under current 
conditions. As a result, we find that the magnitude and imminence of 
threats facing the South Sierra DPS of the foothill yellow-legged frog 
place the DPS in danger of extinction now, and therefore a threatened 
status is not appropriate. Thus, after assessing the best scientific 
and commercial information available, we determine that the South 
Sierra DPS of the foothill yellow-legged frog is in danger of 
extinction throughout all of its range.
    South Coast DPS: There are numerous, severe threats to the South 
Coast DPS of the foothill yellow-legged frog including altered 
hydrology (Factor A), drought (Factor E), nonnative species (Factor C), 
disease and parasites (Factor C), urbanization (including development 
roads) (Factor A), and recreation (Factor E), illegal cannabis 
cultivation (Factor A), extreme floods (Factor E), severe wildfire 
(Factor A), the effects of climate change (e.g., increased 
temperatures, precipitation variability, increased drought frequency 
and duration) (Factor E), and inadequacy of regulatory mechanisms 
(Factor D). After evaluating threats to the DPS and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we conclude that under current conditions, resiliency, 
redundancy, and representation are poor for the South Coast DPS. 
Foothill yellow-legged frogs are mostly extirpated in this DPS and 
currently occur only in two streams. These streams are located close to 
one another, but the foothill yellow-legged frog populations within 
them appear to have lost genetic connectivity. Although the stream 
flows are not regulated by dams, the risk of population decline 
continues to be medium or high under current conditions due to the 
combination of threats identified above altering habitat and impacting 
the DPS. Furthermore, the close proximity of the stream segments to 
each other makes the South Coast DPS especially vulnerable to 
extirpation from a single catastrophic event. Like the other DPSs 
within the southern portion of the species' range, the area associated 
with the South Coast DPS is subject to reduced precipitation and 
drying, which (1) shortens the hydroperiod and negatively affects 
habitat elements that are hydrology-dependent; (2) limits recruitment, 
survival, and connectivity; and (3) exacerbates the effects of other 
threats, such as predation and wildfire. In addition, the current 
occupancy within the DPS is extremely low and the threats acting on the 
DPS are of such extent and magnitude to currently cause significant 
declines. As a result, we find that the magnitude and imminence of 
threats facing the South Coast DPS of the foothill yellow-legged frog 
place the DPS in danger of extinction now, and therefore a threatened 
status is not appropriate. Thus, after assessing the best scientific 
and commercial information available, we determine that currently the 
South Coast DPS of the foothill yellow-legged frog is in danger of 
extinction throughout all of its range.

Status of the South Sierra DPS and South Coast DPS Throughout a 
Significant Portion of Their Ranges

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. We have determined that the South Sierra DPS and the South 
Coast DPS of the foothill yellow-legged frog are in danger of 
extinction throughout all of their ranges, and accordingly we did not 
undertake an analysis of any significant portion of the range for these 
two DPSs. Because both DPSs warrant listing as endangered throughout 
all of their ranges, our determination does not conflict with the 
decision in Center for Biological Diversity v. Everson, 2020 WL 437289 
(D. DC 2020), in which the court vacated the aspect of the Final Policy 
on Interpretation of the Phrase ``Significant Portion of its Range'' in 
the Endangered Species Act's Definitions of ``Endangered Species'' and 
``Threatened Species'' (79 FR 37578; July 1, 2014) that provided the 
Service does not undertake an analysis of significant portions of a 
species' range if the species warrants listing as threatened throughout 
all of its range.

Determination of Status for the South Sierra DPS and South Coast DPS

    Our review of the best available scientific and commercial 
information indicates that the South Sierra DPS and the South Coast DPS 
meet the Act's definition of endangered species. Therefore, we propose 
to list the South Sierra DPS and the South Coast DPS as endangered 
species in accordance with sections 3(6) and 4(a)(1) of the Act.

[[Page 73933]]

Status of the North Feather DPS and Central Coast DPS of the Foothill 
Yellow-Legged Frog Throughout All of Their Ranges

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the North Feather and Central Coast DPSs of the foothill yellow-
legged frog and their habitat. Below we summarize our assessment of 
status of the North Feather DPS and Central Coast DPS under the Act.
    North Feather DPS: Numerous threats are currently acting on the 
North Feather DPS. The North Feather DPS is within the most 
hydrologically altered part of the foothill yellow-legged frog's range 
(Factor A) and potentially is among the most impacted by the latent 
effects from historical mining (Hayes et al. 2016, pp. 53-54) (Factor 
A). Other threats to the DPS include nonnative species (bullfrogs and 
crayfish) (Factor C), impacts to habitat (agriculture, urbanization, 
severe wildfire) (Factor A), recreation (Factor E), the effects of 
climate change (Factor E), and inadequacy of regulatory mechanisms 
(Factor D). After evaluating threats to the DPS and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we conclude that under current conditions, resiliency, 
redundancy, and representation for the North Feather DPS are reduced.
    The North Feather DPS occupies a relatively small area and several 
streams or occurrences have been extirpated from past impacts (eastern 
portion of range, southwestern area near Lake Oroville, and some 
occurrences in northern Butte County) (CDFW 2020, dataset, entire; 
Service 2021, figure 49, p. 131). The North Feather DPS also has the 
highest average relative risk of population decline with only 16 (15 
percent) of the 109 analyzed stream segments in the low risk category 
and 34 stream segments (31 percent) in the high risk category. Overall 
abundance of foothill yellow-legged frogs for the North Feather DPS is 
largely unknown, but egg mass densities are very low in the two 
regulated stream reaches that have long-term monitoring (Rose et al. 
2020, pp. 63-64, table 1). For example, sections of the Cresta reach of 
the North Feather River that historically had relatively high numbers 
of foothill yellow-legged frog egg masses did not have egg masses or 
were extremely reduced for several years (2006-2017) (CDFW 2019, p. 31; 
Dillingham 2019, p. 7).
    Under current conditions, resiliency in the North Feather DPS is 
reduced, largely because of the DPS's occupation of a small geographic 
area, range contraction, the relatively high risk of the DPS's decline, 
and the area's high degree of hydrological alteration. However, the 
North Feather DPS still currently contains a relatively high proportion 
of occurrence records with 42 percent of all known occurrences being 
from the 2010-2020 timeframe (Service 2021, table 10, figure 49, pp. 
125, 131). As a result, occupancy for the North Feather DPS is good, 
based on a majority of records being within the 2000-2020 timeframe, 
but abundance is low where there has been population monitoring. 
Current redundancy is limited in the North Feather clade. The North 
Feather DPS not only occupies the smallest area, but its occupied 
stream segments are not well-distributed over the geographical area it 
occupies. Current representation of the DPS is most likely reduced due 
to past loss of populations.
    In 2001, the FERC issued an order to the licensee responsible for 
flow regulation on the Cresta and Poe reaches of the North Feather 
River (Rock Creek-Cresta Hydroelectric Project (FERC Project No. 1962) 
Pacific Gas and Electric Company (PG&E)). The order required PG&E to 
develop a plan to ensure recreational and pulse flow releases did not 
negatively impact the foothill yellow-legged frog. The order also 
required the establishment of an Ecological Resources Committee (ERC) 
to evaluate effects of flows and provide adaptive management strategies 
if flows had a negative impact on the foothill yellow-legged frog 
populations within the two reaches. In 2006, flow releases for 
recreational boating were discontinued on the Cresta reach due to 
possible impacts from flows resulting in low foothill yellow-legged egg 
masses that year. In 2009 and again in 2014, modified flow programs 
were implemented to mimic natural flow regimes by reducing flows in 
spring and summer (April through the foothill yellow-legged frog's 
breeding season) (GANDA 2018, pp. 1-2). We expect these measures to 
continue due to the establishment of the ERC on monitoring impacts to 
foothill yellow-legged frog populations on the two reaches. As a 
result, there are some signs of improved abundance since 2018, in the 
Cresta reach of the North Feather River following the above described 
modifications of the regulated flow regime to more natural conditions. 
Additional conservation efforts have been implemented to improve 
abundance of the North Feather DPS including in-situ and ex-situ 
rearing of foothill yellow-legged frogs for reintroduction (GANDA 2018, 
pp. 1-3, 13, table 2; Dillingham 2019, pp. 7-9; Rose et al. 2020, pp. 
63-64, 76, table 1, figure 4). The Forest Service has noted habitat 
improvements in breeding areas of the Cresta reach and expects 
abundances and breeding activity to continue to increase in response to 
conservation efforts associated with in-situ and ex-situ rearing 
efforts (Dillingham 2019, pp. 7-9). In addition, the environmental 
condition of streams in the range of the North Feather DPS exhibit 
colder stream temperatures. These cooler water temperatures, although 
not currently preferable for the foothill yellow-legged frog, may help 
to provide climatic resiliency during periods of hot weather that may 
increase stream temperatures and may extend breeding and rearing 
timeframes. In addition, the existing conservation efforts to improve 
populations and regulatory measures to benefit habitat conditions as 
described above currently document improvements to the DPS's overall 
current condition. After evaluating threats to the species and 
assessing the cumulative effect of the threats under the section 
4(a)(1) factors, we have determined that despite the current condition 
of the DPS being reduced, the population and habitat factors used to 
determine the resiliency, representation, and redundancy for the DPS 
have not been reduced to such a degree to consider the North Feather 
DPS currently in danger of extinction throughout its range.
    However, threat conditions in the future are likely to 
substantially impact populations of the North Feather DPS. Because of 
the current cold stream temperatures, future climatic conditions that 
may increase stream temperatures may potentially benefit many of the 
North Feather DPS populations; however, the negative effects of 
increases in streamflow variability due to climate change (i.e., 
drought/flood events, snow/rain events) and residual environmental 
stochasticity likely outweigh the benefit of any warmer stream 
temperatures. Increased water demand and anticipated additional 
regulation to an already highly regulated hydrologic condition of the 
DPSs habitat will further limit the DPS's capability to maintain 
adequate population sizes to support the DPS's metapopulation 
structure. Nonnative species (bullfrogs and crayfish) will continue to 
impact the DPS and their impacts may increase as temperatures warm, 
allowing for spread of warm water species such as bullfrogs and 
smallmouth bass. Trends indicate that the amount of area severely 
burned annually by wildfires has been

[[Page 73934]]

growing sharply in the range of the North Feather DPS (Service 2021, 
figures 38 and 39, pp. 105-106) and negative consequences from 
wildfire-related sedimentation to foothill yellow-legged frog 
reproduction have been documented in this DPS (Service 2021, pp. 86-
87). The populations of the North Feather DPS occupy an area small 
enough that a large catastrophic event, such as a severe wildfire or 
prolonged drought, could result in a severe reduction in population 
size and extent for the DPS. Future resiliency for the North Feather 
DPS will be markedly reduced as a result of these increases in threats 
and increases in the synergistic effects of threat interactions. Thus, 
the projected increases in average relative risk of decline under 
future conditions under the mean change scenario are likely to decrease 
occupancy, abundance, and connectivity, with resiliency being markedly 
reduced from the DPS's current condition, putting the North Feather DPS 
at risk of functional extirpation or extirpation within 40 years.
    As a result of the DPS having a large percentage (42 percent) of 
recently occupied occurrences (2010-2020) within the occupied stream 
segments, and implementation of conservation measures to reduce the 
effects of altered stream hydrology and provide for an increase in 
populations, we have determined that the current condition of the DPS, 
although reduced, still exhibits sufficient resiliency, redundancy, and 
representation and would provide for, at a minimum, pockets of 
favorable conditions that allow the North Feather DPS to currently 
sustain its existing populations. However, future impacts from the 
threats facing the DPS are likely to cause declines in the DPS's 
population size and distribution. Thus, after assessing the best 
available information, we conclude that the North Feather DPS of the 
foothill yellow-legged frog is not currently in danger of extinction 
but is likely to become in danger of extinction within the foreseeable 
future throughout all of its range.
    Central Coast DPS: Numerous threats are currently acting on the 
Central Coast DPS including altered hydrology (Factor A), disease 
(Factor C), drought (Factor A), nonnative bullfrogs (Factor C), impacts 
to habitat (urbanization (including development and roads), 
agriculture, trespass cannabis cultivation, extreme floods, and 
wildfire) (Factor A), recreation (Factor E), the effects of climate 
change (Factor E), and inadequacy of regulatory mechanisms (Factor D). 
Human land use and population (urban development) in the northern 
portions of the DPS's range are high, and the proportion of forest and 
shrub cover across the DPS's range is low, with large areas being made 
up of lower elevation open oak woodlands or foothill grassland 
habitats. Seasonal precipitation within the range of the Central Coast 
DPS is extremely variable year-to-year, making stream habitat for the 
Central Coast DPS subject to drying. This, in turn, shortens the 
breeding season; negatively affects habitat elements that are 
hydrology-dependent; limits recruitment, survival, and connectivity; 
and exacerbates the effects of other threats (e.g., wildfire, drought, 
nonnative predators, disease, and the effects of climate change). 
However, this variability has also resulted in the Central Coast area 
of California (including the area occupied by the Central Coast DPS) 
containing a high number of freshwater species that have evolved 
adaptations to their environment (Howard et al. 2013, p. 5). Below we 
summarize the resiliency, redundancy, and representation of the Central 
Coast DPS.
    The Central Coast DPS has undergone historical range contraction in 
portions of its northern (Contra Costa, Alameda, San Mateo, and 
northern Santa Cruz Counties) and central (southern Santa Clara and 
northern San Benito Counties) regions. Currently, two clusters of 
stream segments have had recent (2000-2020) detections of the species, 
one cluster in the southern part and one cluster in the northern part 
of the DPS's range (Service 2021, figure 52, p. 137). Population size 
and abundance for the Central Coast DPS have been historically, and 
continue to be, small, with those populations in unregulated streams 
being larger and more productive (Service 2021, pp. 136-137 (8.2 
Central Coast)). The southern cluster appears to have functional and 
genetic connectivity (McCartney-Melstad et al. 2018, p. 117, figure 3), 
which assists in maintaining the cluster's metapopulation integrity. 
The southern cluster also has fewer human-caused threats (urbanization, 
high-level recreation) due to its distance away from highly human-
populated areas and its location on public lands (BLM's Clear Creek 
Management Area (CCMA)). Populations within the CCMA in San Benito and 
Fresno Counties are being monitored and managed by BLM, and currently 
appear to be self-sustaining (BLM 2014, pp. 4-77, 99-100). The northern 
cluster is proximate to highly urbanized areas of the south San 
Francisco Bay area and San Jose, California. The northern cluster also 
exhibits some genetic differentiation among subpopulations, indicating 
a lack of functional connectivity (McCartney-Melstad et al. 2018, p. 
117, figure 3). However, two HCP/NCCPs (East Contra Costa and Santa 
Clara Valley) (Jones & Stokes 2006, entire; ICF Jones & Stokes 2009, 
entire) that identify the foothill yellow-legged frog as a covered 
species have been approved and implemented. These plans assist in 
ameliorating the current threats acting on the northern populations of 
the Central Coast DPS and help conserve the DPS and its habitat within 
their jurisdictional boundaries.
    Current resiliency of the Central Coast DPS is substantially 
reduced due to past impacts limiting connectivity between populations 
and existing populations having smaller population abundance and 
breeding (Rose et al. 2020, p. 63, table 1). The average risk of 
population decline for the Central Coast DPS is considered high and 
numerous threats are currently acting on the DPS (altered hydrology, 
drought, nonnative species, disease, and urbanization). The current 
overall redundancy for the Central Coast DPS is considered adequate to 
maintain the existing populations of the DPS. This is because the 
Central Coast DPS has numerous occupied stream segments that are 
spatially distributed across the DPS's range, and those stream segments 
exhibit variable environmental conditions providing for, at a minimum, 
refugia for the population. As a result of this distribution, the 
likelihood that a single catastrophic event would impact a significant 
proportion of the Central Coast DPS's populations to the point of 
extirpation or functional extirpation is extremely small. Current 
representation for the Central Coast DPS is considered sufficient to 
maintain its adaptive capacity. The Central Coast DPS has evolved in an 
area with high climatic variability and is most likely adapted to 
environmental changes. The Central Coast DPS is also one of the most 
genetically divergent for the foothill yellow-legged frog, indicating 
that the DPS still contains a significant amount of the taxon's overall 
genetic diversity.
    In the future, the average risk of decline for the existing 
populations is expected to increase by 14 percent and the number of 
populations at high risk of decline are expected to increase by 69 
percent, under the mean change scenario. These changes are a result of 
increases in threats such as climate-induced demand for surface waters 
that is projected to increase by 5 to 20 percent (from 1900-1970 
levels) by mid-century (2050) (Averyt et al. 2013, p. 7, figure 7). 
Future increases in severe wildfires are expected. Despite wildfire 
trends in the Central Coast DPS being

[[Page 73935]]

stable between 1950 and 2018 (Service 2021, Figure 38), recent events 
such as the fires in 2020 in the San Mateo-Santa Cruz Unit (CZU) 
(35,009 hectares (ha) (86,509 acres (ac)) (Santa Cruz and San Mateo 
Counties) and Santa Clara Unit (SCU) (160,508 ha (396,624 ac)) (Santa 
Clara, Alameda, Stanislaus Counties) Lightning Complex are examples of 
expected increasing trends in wildfire activity in the future (CALFIRE 
2021, entire). Under the lower change scenario, the Central Coast DPS's 
resiliency would be slightly reduced. Under the mean change scenario, 
resiliency would be markedly reduced from current condition due to 
reductions in population numbers and distribution (reduction in 
redundancy). This reduction in resiliency under the mean change 
scenario would put the Central Coast DPS at risk of functional 
extirpation or extirpation in 40 years.
    After evaluating threats to the Central Coast DPS and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we find that the Central Coast DPS of the foothill yellow-
legged frog currently sustains numerous populations and contains 
habitat distributed throughout the DPS's range (redundancy). These 
widely distributed populations provide for the genetic and ecological 
representation for the DPS across its range. Therefore, the current 
resiliency, redundancy, and representation are sufficient to prevent 
the current threats acting on the Central Coast DPS from causing it to 
be in danger of extinction anywhere within its range. Thus, the Central 
Coast DPS of the foothill yellow-legged frog is not currently in danger 
of extinction throughout its range, and therefore, the Central Coast 
DPS does not meet the Act's definition of endangered. However, based on 
our projections of future occupancy (which are currently low and show 
poor connectivity), modeled risk of decline assessments from the PVA, 
and the existing and increased threats in the future on the DPS from 
increasing water demand, increases in wildfire frequency and intensity 
due to climate change conditions will further impact abundance and 
connectivity of populations and cause the DPS's habitat to become 
increasingly less able to support foothill yellow-legged frog 
populations into the future. Thus, after assessing the best available 
information, we conclude that the Central Coast DPS of the foothill 
yellow-legged frog is likely to become in danger of extinction within 
the foreseeable future throughout all of its range.

Status of the North Feather DPS and Central Coast DPS of the Foothill 
Yellow-Legged Frog Throughout a Significant Portion of Their Ranges

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. The court in Center for Biological Diversity v. Everson, 
2020 WL 437289 (D.D.C. Jan. 28, 2020) (Center for Biological 
Diversity), vacated the aspect of the Final Policy on Interpretation of 
the Phrase ``Significant Portion of Its Range'' in the Endangered 
Species Act's Definitions of ``Endangered Species'' and ``Threatened 
Species'' (79 FR 37578; July 1, 2014) that provided that the Service 
does not undertake an analysis of significant portions of a species' 
range if the species warrants listing as threatened throughout all of 
its range. Therefore, we proceed to evaluating whether the North 
Feather DPS or Central Coast DPS is endangered in a significant portion 
of its range--that is, whether there is any portion of either DPSs' 
range for which both (1) the portion is significant; and (2) the 
species is in danger of extinction in that portion. Depending on the 
case, it might be more efficient for us to address the ``significance'' 
question or the ``status'' question first. We can choose to address 
either question first. Regardless of which question we address first, 
if we reach a negative answer with respect to the first question that 
we address, we do not need to evaluate the other question for that 
portion of either DPS's range.
    Following the court's holding in Center for Biological Diversity, 
we now consider whether there are any significant portions of the 
species' range where either DPS is in danger of extinction now (i.e., 
endangered). In undertaking this analysis for the North Feather DPS and 
Central Coast DPS, we choose to address the status question first--we 
consider information pertaining to the geographic distribution of both 
the species and the threats that the two DPSs face to identify any 
portions of either DPS's range where either is endangered.
    For North Feather DPS and Central Coast DPS, we considered whether 
the threats are geographically concentrated in any portion of the DPS's 
ranges at a biologically meaningful scale. We examined the following 
threats for the North Feather DPS: Altered stream hydrology, latent 
effects from historical mining, nonnative species, impacts to the DPS's 
habitat (agriculture, urbanization, wildfire), recreation, and the 
effects of climate change, including cumulative effects. For the 
Central Coast DPS, we examined: Altered stream hydrology, disease, 
drought, nonnative species, impacts to habitat (urbanization (including 
roads and recreation), agriculture, trespass cannabis cultivation, 
extreme floods, and wildfire), and the effects of climate change, 
including cumulative effects. The major driving forces of altered 
stream hydrology, wildfire, disease, nonnative species, and the effects 
of climate change are occurring throughout each DPS at similar levels 
and we did not find a concentration of any of these threats in any 
portion of either the North Feather or Central Coast DPS's range at a 
biologically meaningful scale.
    Thus, there are no portions of the North Feather DPS's or Central 
Coast DPS's range where the threats facing the species are concentrated 
to a degree where the species in that portion would have a different 
status from its overall DPS status. Therefore, no portion of the North 
Feather DPS's or Central Coast DPS's range provides a basis for 
determining that the North Feather DPS or Central Coast DPS is in 
danger of extinction in a significant portion of its range. We 
determine that the two DPSs are likely to become in danger of 
extinction within the foreseeable future throughout all of their 
ranges. This does not conflict with the courts' holdings in Desert 
Survivors v. U.S. Department of the Interior, 321 F. Supp. 3d 1011, 
1070-74 (N.D. Cal. 2018), and Center for Biological Diversity v. 
Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, in reaching 
this conclusion, we did not need to consider whether any portions are 
significant and therefore did not apply the aspects of the Final 
Policy's definition of ``significant'' that those court decisions held 
were invalid.

Determination of Status for the North Feather DPS and Central Coast DPS 
of the Foothill Yellow-Legged Frog

    Our review of the best scientific and commercial information 
available indicates that the North Feather DPS and Central Coast DPS of 
the foothill yellow-legged frog are likely to become endangered species 
within the foreseeable future throughout their ranges and thus meet the 
Act's definition of threatened species. Therefore, we propose to list 
the North Feather DPS and Central Coast DPS of the foothill yellow-
legged frog as threatened species in accordance with sections 3(20) and 
4(a)(1) of the Act.

[[Page 73936]]

Status of the North Coast DPS and North Sierra DPS of the Foothill 
Yellow-Legged Frog Throughout All of Their Ranges

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the North Coast DPS and the North Sierra DPS of the foothill yellow-
legged frog and its habitat. Below we summarize our assessment of 
status of the North Coast DPS and the North Sierra DPS under the Act. 
In the SSA report, we provided information regarding the current and 
future conditions of the North Coast DPS in Oregon and California as 
separate analysis units. To be consistent, we describe the conditions 
of the Oregon and California portions of the DPS separately below, but 
we combine these analyses and present the DPS as one entity for our 
determination of overall status under the Act.
    North Coast DPS (Oregon): The major threats that are affecting the 
foothill yellow-legged frog in the North Coast DPS in Oregon include 
altered hydrology (Factor A), nonnative species (Factor C), agriculture 
(including water diversion and fluctuation caused by irrigation) 
(Factor A), mining (Factor A), urbanization (including development and 
roads) (Factor A), and recreation (Factor E).
    Current conditions of the North Coast DPS in Oregon include legacy 
impacts from historical habitat loss and alteration of habitat and 
resulting range contraction. The current extent of the DPS's range in 
Oregon has been fragmented and the populations remaining have lost some 
connectivity, with smaller populations sometimes being isolated. 
Evidence of this isolation has been supported by genetic research that 
found the DPS in Oregon subdivided into three genetic groups based on 
locality (McCartney-Melstad et al. 2018, p. 117, figure 3). Abundance 
information also appears to indicate the fragmented populations are 
lower in abundance than past abundance estimates (Borisenko and Hayes 
1999, pp. 20-21; Olson and Davis 2009, p. 26). Although occupancy and 
connectivity are poor for the DPS in Oregon as a whole, there appear to 
be some strongholds for the foothill yellow-legged frog (Service 2021, 
figure 55, p. 151). The areas in the central and southwestern portions 
of the DPS in Oregon appear to be most stable with numerous occupied 
stream segments that are both close together and at a relatively low 
risk of decline. According to the PVA, the average relative risk of 
population decline in the North Coast DPS in Oregon is the second-
lowest across all DPSs. In addition, the majority of stream segments in 
this unit are in the low relative risk of decline category. This is 
partly because most stream segments in Oregon do not have regulated 
flows which are associated with dams. In addition, conservation efforts 
such as rangewide conservation planning and habitat connectivity 
prioritization are focusing management on the North Coast DPS in Oregon 
(Service 2021, table 9, pp. 117-120). Although habitat impacts 
resulting from present-day threats are currently negatively affecting 
the North Coast DPS in Oregon, the DPS in Oregon still has a sufficient 
degree of resiliency, redundancy, and representation, due to the 
lessened magnitude and extent of threats acting on the DPS, such that 
we do not consider these present-day effects to place the species in 
danger of extinction.
    North Coast DPS-California: Altered stream hydrology (Factor A) is 
among the most impactful threats to the North Coast DPS in California. 
Other major threats that likely have or are contributing to localized 
declines in the DPS in California include nonnative species (Factor C), 
habitat impacts from agriculture, mining, and urbanization (including 
development and roads) (Factor A), and recreation (Factor E). Trespass 
cannabis cultivation (Factor A) is also an extensive threat in the 
North Coast DPS in California (CDFW 2019b, pp. 97-98). Illegal water 
diversions and pesticides for illegal cannabis are reportedly linked to 
local declines of foothill yellow-legged frogs in the Eel River and 
South Fork Trinity River (Service 2019, p. 33).
    Despite several documented local extirpations, the North Coast DPS 
in California contains the most abundant foothill yellow-legged frog 
populations and the majority (1,443 of 2,425 for the species) of stream 
segments that have had recent (2000-2020) detections of the species 
(Service 2021, Table 10, Figure 48). Stream segments with recent 
detections also have good connectivity and are distributed over a large 
area. The North Coast DPS in California also contains a large number of 
stream segments (382) in the low risk of decline category. In addition, 
conservation efforts such as rangewide conservation planning and other 
regulatory measures to manage streams to benefit the North Coast DPS 
are currently being implemented in California (Service 2021, table 9, 
pp. 117-120). Although habitat impacts resulting from present-day 
threats are currently negatively affecting the North Coast DPS in 
California, the DPS in California still has a sufficient degree of 
resiliency, redundancy, and representation, due to the health and 
number of populations and magnitude and extent of threats acting on the 
DPS, such that we do not consider these present-day effects to place 
the DPS in danger of extinction.
    After assessing the best scientific and commercial information 
available, and based on the information on the North Coast DPS's 
overall current condition above, we have determined that the North 
Coast DPS (in California and Oregon) of the foothill yellow-legged frog 
is not currently in danger of extinction throughout all of its range. 
Below, we review the North Coast DPS's future condition and status.
    Future Condition of the North Coast DPS: Over the next 40 years 
(our timeframe of foreseeable future), the projected increases in risk 
of decline and the increasing risk of serious threats indicate that the 
resiliency of the North Coast DPS will decrease in the future (Service 
2021, table 19, pp. 180-181). This decline is expected to be largely 
related to the altered stream hydrology (in California) in the mainstem 
river systems and threats associated with severe wildfire events 
exacerbated by changes in climatic conditions. However, the North Coast 
DPS in Oregon has the lowest risk of decline under the mean and higher 
change scenarios and has the second-lowest risk of decline under the 
lower change scenario. In addition, the percent forest and shrub cover 
for the entire DPS is projected to change very little by 2060 (less 
than 0.3 percent of total area under the mean change scenario) in the 
North Coast DPS overall (California and Oregon data summarized 
together) (Sleeter and Kreitler 2020, unpublished data). This would 
result in a relatively stable upland habitat conditions for the DPS 
over this timeframe. This DPS overall is also likely to be more 
resilient to projected changes in climate variables (i.e., stream 
temperature and annual streamflow). For example, projected increases in 
stream temperature could increase population growth rates in those 
streams that tend to be cooler than in the rest of the species' range. 
In addition, although resiliency for the North Coast DPS will be 
reduced, the reduction will not be significantly different from current 
condition. This is mostly because the North Coast DPS has a large 
number of occupied stream segments, contains populations with high 
abundances, is distributed relatively uniformly across a large 
geographic area, and has good connectivity between populations, making 
it able to withstand the anticipated variation and increase of

[[Page 73937]]

stochastic events. Regulatory mechanisms such as the Forest Service's 
and BLM's Sensitive Species Program and habitat management programs 
under the Northwest Forest Plan which provides for species management 
and habitat protection for activities on their lands will continue to 
be implemented for a large portion of the DPS. As a result, the North 
Coast DPS's resiliency would most likely be only slightly reduced from 
the threats it will face in the foreseeable future over the next 40 
years due to its heightened current condition. Therefore, due to the 
DPS's current and projected high occupancy level, its abundance, 
connectivity, and distribution of populations within the DPS as well as 
implementation of measures to reduce threats, we have determined that 
the North Coast DPS will continue to have a sufficient degree of 
resiliency, redundancy, and representation such that we do not 
anticipate the future threats to limit the DPS's ability to maintain 
populations in the wild.
    After review of the threats identified above and cumulative effects 
facing the North Coast DPS, as well as existing conservation measures, 
we conclude that threats have likely impacted individuals or localized 
populations of the North Coast DPS. However, the magnitude and extent 
of these impacts into the future will not significantly impact the 
resiliency, representation, or redundancy for the DPS or result in a 
decline in the overall distribution or general demographic condition of 
the DPS such that it is likely to become in danger of extinction in the 
foreseeable future throughout the DPS's range.
    North Sierra DPS: The major threats that likely have or are 
contributing to declines of the foothill yellow-legged frog in the 
North Sierra DPS include altered stream hydrology (Factor A), nonnative 
species (Factor C), habitat impacts (agriculture, mining, urbanization 
(including development and roads) (Factor A) and recreation (Factor E), 
and the effects of climate change (Factor E). The North Sierra DPS is 
in the most hydrologically altered part of the foothill yellow-legged 
frog's range and contains a high density of hydropower dams (CDFW 
2019b, p. 97). While the North Sierra DPS has a high proportion of 
forest and shrub cover (86 percent), it may be affected by agricultural 
activities (vineyards) adjacent to habitat in the foothill portions of 
the northern Central Valley (Service 2021, supplementary figure 1, p. 
224). The northern Sierra Nevada (North Feather and North Sierra DPSs) 
is also suspected to be the most impacted from the latent effects from 
historical mining (Hayes et al. 2016, pp. 53-54).
    Despite the threats acting on the North Sierra DPS, its populations 
have the lowest risk of decline across the DPS's range due to it having 
a large proportion of occupied streams containing populations that are 
both robust and stable. The majority (65 percent) of the DPS's 278 
analyzed stream segments are currently in the low relative risk 
category. The North Sierra DPS is made up of a dense network of 
occupied stream segments that are distributed across the range of the 
DPS. There are few documented extirpations of occurrences in the North 
Sierra DPS. As a result, the resiliency, redundancy, and representation 
across the DPS are considered sufficient to reduce the impact of 
threats and currently maintain populations in the wild.
    In the future, the North Sierra DPS is expected to decline due to 
alterations associated with regulated water flows. However, these 
declines are not expected to impact the North Sierra DPS to such a 
degree that populations would be significantly impacted. The PVA 
determined that the North Coast DPS would have the lowest risk of 
decline under the lower change scenario and the second-lowest risk of 
decline under the mean and higher change scenarios. As a result, we 
expect resiliency, redundancy, and representation across the DPS to 
remain sufficient for the DPS to maintain populations in the wild into 
the foreseeable future.
    We have reviewed the current threats identified above and 
cumulative effects facing the North Coast and North Sierra DPSs, and 
evaluated the condition of the resiliency, representation, and 
redundancy for each of the DPSs. Based on the favorable conditions 
currently measured by the resiliency, redundancy and representation 
across the DPSs, the threats acting on the two DPSs are not of such 
magnitude, extent, and imminence that they are causing the two DPSs to 
be in danger of extinction now throughout their ranges.
    The future threats acting on and driving the status of the two DPSs 
include altered hydrology (either through stream flows or past stream 
alterations) and the effects of climate change, which may result in 
increased hydrological changes or severity of habitat loss from 
wildfire impacts. We anticipate that, although the risk of decline will 
increase due to the threats acting on the two DPSs into the future, the 
two DPSs' resiliency, representation, and redundancy are projected to 
sufficiently reduce the effect of future impacts to such a degree that 
populations of both DPSs would be able maintain viability into the 
future.
    Thus, after assessing the best scientific and commercial 
information available, we conclude that the North Coast DPS (in 
northern California and Oregon) and the North Sierra DPS (located 
primarily in Yuba, Sierra, Nevada, and Placer Counties, California) are 
not currently in danger of extinction and not likely to become in 
danger of extinction within the foreseeable future throughout their 
respective ranges.

Status of the North Coast DPS and North Sierra DPS of the Foothill 
Yellow-Legged Frog Throughout a Significant Portion of Their Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. Having determined that the North Coast DPS and North Sierra 
DPS are not in danger of extinction or likely to become so in the 
foreseeable future throughout all of their respective ranges, we now 
consider whether either may be in danger of extinction or likely to 
become so in the foreseeable future in a significant portion of their 
respective ranges--that is, whether there is any portion of the DPSs' 
ranges for which it is true that both (1) the portion is significant; 
and (2) the DPS is in danger of extinction now or likely to become so 
in the foreseeable future in that portion. Depending on the case, it 
might be more efficient for us to address the ``significance'' question 
or the ``status'' question first. We can choose to address either 
question first. Regardless of which question we address first, if we 
reach a negative answer with respect to the first question that we 
address, we do not need to evaluate the other question for that portion 
of the DPS's range.
    In undertaking this analysis for the North Coast DPS and North 
Sierra DPS, we choose to address the status question first--we consider 
information pertaining to the geographic distribution of both the DPSs 
and the threats that the DPSs face to identify any portions of the 
range where the DPSs are endangered or threatened.
    For the North Coast DPS and North Sierra DPS, we considered whether 
the threats are geographically concentrated in any portion of the DPSs' 
ranges at a biologically meaningful scale. We examined the following 
threats: Hydrological alteration of streams (Factor A), latent effects 
from historical mining (Factor A), predation from nonnative species 
(bullfrogs and crayfish) (Factor C), other impacts to

[[Page 73938]]

habitat (agriculture, urbanization, severe wildfire) (Factor A), 
recreation (Factor E), and the effects of climate change (Factor E), 
including cumulative effects. In our analysis, we did not find any 
portion of either the North Coast DPS's range or the North Sierra DPS's 
range where the threats identified above are currently acting at a 
biologically meaningful scale such that any portion of the DPSs' ranges 
may be endangered, or where threats are likely to act on either DPS 
into the future such that any portion may be threatened. Occupied 
stream segments are distributed throughout each of the DPSs, and 
connectivity in the majority of each DPS is considered to be good 
except within the Oregon portion of the North Coast DPS. However, the 
Oregon portion also has fewer regulated streams, and populations, 
although small, are in a low risk of decline both now and into the 
future. Therefore, no portion of the two DPSs' ranges provides a basis 
for determining that either DPS is in danger of extinction now or 
likely to become so in the foreseeable future in a significant portion 
of its range, and we find that the DPSs are not in danger of extinction 
now or likely to become so in the foreseeable future in any significant 
portion of their ranges. This does not conflict with the courts' 
holdings in Desert Survivors v. U.S. Department of the Interior, 321 F. 
Supp. 3d 1011, 1070-74 (N.D. Cal. 2018), and Center for Biological 
Diversity v. Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, 
in reaching this conclusion, we did not need to consider whether any 
portions are significant and therefore did not apply the aspects of the 
Final Policy's definition of ``significant'' that those court decisions 
held were invalid.

Determination of Status of the North Coast DPS and North Sierra DPS of 
the Foothill Yellow-Legged Frog

    Our review of the best scientific and commercial information 
available indicates that the North Coast DPS and North Sierra DPS of 
the foothill yellow-legged frog do not meet the Act's definition of an 
endangered species or a threatened species in accordance with sections 
3(6) and 3(20) of the Act. Therefore, we find that listing the North 
Coast DPS and North Sierra DPS of the foothill yellow-legged frog under 
the Act is not warranted at this time.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness, and 
conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and other countries and calls for recovery actions to be carried 
out for listed species. The protection required by Federal agencies and 
the prohibitions against certain activities are discussed, in part, 
below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Section 4(f) of the Act calls for the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning consists of preparing draft and final recovery 
plans, beginning with the development of a recovery outline and making 
it available to the public within 30 days of a final listing 
determination. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. Revisions of the plan may be done to address 
continuing or new threats to the species, as new substantive 
information becomes available. The recovery plan also identifies 
recovery criteria for review of when a species may be ready for 
reclassification from endangered to threatened (``downlisting'') or 
removal from protected status (``delisting''), and methods for 
monitoring recovery progress. Recovery plans also establish a framework 
for agencies to coordinate their recovery efforts and provide estimates 
of the cost of implementing recovery tasks. Recovery teams (composed of 
species experts, Federal and State agencies, nongovernmental 
organizations, and stakeholders) are often established to develop 
recovery plans. When completed, the recovery outline, draft recovery 
plan, and the final recovery plan will be available on our website 
(https://www.fws.gov/endangered), or from our Sacramento Fish and 
Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    If any of the DPSs identified above are listed, funding for 
recovery actions will be available from a variety of sources, including 
Federal budgets, State programs, and cost-share grants for non-Federal 
landowners, the academic community, and nongovernmental organizations. 
In addition, pursuant to section 6 of the Act, the State of California 
would be eligible for Federal funds to implement management actions 
that promote the protection or recovery of the DPSs. Information on our 
grant programs that are available to aid species recovery can be found 
at: https://www.fws.gov/grants.
    Although the four DPSs are only proposed for listing under the Act 
at this time, please let us know if you are interested in participating 
in recovery efforts for this species. Additionally, we invite you to 
submit any new information on this species whenever it becomes 
available and any information you may have for recovery planning 
purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as an 
endangered or threatened species and with respect to its critical 
habitat, if any is designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any action that is likely to jeopardize the 
continued existence of a species proposed for listing or result in 
destruction or adverse modification of proposed critical habitat. If a 
species is listed subsequently, section 7(a)(2) of the Act requires 
Federal agencies to ensure that activities they authorize, fund, or 
carry out are not likely to jeopardize the continued existence of the 
species or destroy or adversely modify its critical habitat. If a 
Federal action may affect a listed species or its

[[Page 73939]]

critical habitat, the responsible Federal agency must enter into 
consultation with the Service.
    Examples of Federal agency actions within the species' habitat 
within the DPSs that may require conference or consultation or both, as 
described in the preceding paragraph, include but are not limited to 
management and any other landscape-altering activities on Federal lands 
administered by the U.S. Fish and Wildlife Service, Forest Service, 
BLM, and National Park Service; issuance of section 404 Clean Water Act 
(33 U.S.C. 1251 et seq.) permits by the U.S. Army Corps of Engineers; 
construction and maintenance of roads, bridges, or highways by the 
Federal Highway Administration; water management and conveyance 
activities by the Bureau of Reclamation; and licensing for hydropower 
and safety of dams by the FERC.

South Sierra DPS and South Coast DPS--Proposed Endangered Status

    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to endangered wildlife. 
The prohibitions of section 9(a)(1) of the Act, codified at 50 CFR 
17.21, make it illegal for any person subject to the jurisdiction of 
the United States to take (which includes harass, harm, pursue, hunt, 
shoot, wound, kill, trap, capture, or collect; or to attempt any of 
these) endangered wildlife within the United States or on the high 
seas. In addition, it is unlawful to import; export; deliver, receive, 
carry, transport, or ship in interstate or foreign commerce in the 
course of commercial activity; or sell or offer for sale in interstate 
or foreign commerce any species listed as an endangered species. It is 
also illegal to possess, sell, deliver, carry, transport, or ship any 
such wildlife that has been taken illegally. Certain exceptions apply 
to employees of the Service, the National Marine Fisheries Service, 
other Federal land management agencies, and State conservation 
agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered wildlife under certain circumstances. Regulations 
governing permits are codified at 50 CFR 17.22. With regard to 
endangered wildlife, a permit may be issued for the following purposes: 
For scientific purposes, to enhance the propagation or survival of the 
species, and for incidental take in connection with otherwise lawful 
activities. The statute also contains certain exemptions from the 
prohibitions, which are found in sections 9 and 10 of the Act.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on proposed and ongoing activities within the range of the 
species proposed for listing.
    Because activities being implemented in the range of the species 
are variable and have variable impacts depending on the nature of the 
project, we are unable at this time to identify any specific activities 
within the range of the species that would not constitute a violation 
of section 9, as effects of any actions on the species are fact-pattern 
specific. However, actions whose effects do not extend into foothill 
yellow-legged frog habitat are unlikely to result in section 9 
violations.
    Based on the best available information, the following activities 
may result in a violation of section 9 of the Act if they are not 
authorized in accordance with applicable law; this list is not 
comprehensive:
    Activities that the Service believes could potentially harm the 
foothill yellow-legged frog and result in ``take'' include, but are not 
limited to:
    (1) Unauthorized handling or collecting of the species;
    (2) Destruction/alteration of the species' habitat by discharge of 
fill material, draining, ditching, tiling, pond construction, stream 
channelization or diversion, or diversion or alteration of surface or 
ground water flow;
    (3) Inappropriate livestock grazing that results in direct or 
indirect destruction of riparian habitat;
    (4) Pesticide applications in violation of label restrictions;
    (5) Introduction of nonnative species that compete with or prey 
upon foothill yellow-legged frogs, such as the introduction of 
nonnative bullfrogs or nonnative fish; and
    (6) Modification of the channel or water flow of any stream or 
removal or destruction of vegetation or stream substrate in any body of 
water in which the foothill yellow-legged frog is known to occur.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Sacramento 
Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

North Feather DPS and Central Coast DPS--Proposed Threatened Status

    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on proposed and ongoing activities within the range of the 
species proposed for listing. The discussion below regarding protective 
regulations under section 4(d) of the Act for the proposed threatened 
North Feather DPS and Central Coast DPS complies with our policy.

II. Proposed Rule Issued Under Section 4(d) of the Act for the North 
Feather DPS and the Central Coast DPS of the Foothill Yellow-Legged 
Frog

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the Secretary shall issue such regulations as she deems 
necessary and advisable to provide for the conservation of species 
listed as threatened. The U.S. Supreme Court has noted that statutory 
language like ``necessary and advisable'' demonstrates a large degree 
of deference to the agency (see Webster v. Doe, 486 U.S. 592 (1988)). 
Conservation is defined in the Act to mean the use of all methods and 
procedures which are necessary to bring any endangered species or 
threatened species to the point at which the measures provided pursuant 
to the Act are no longer necessary. Additionally, the second sentence 
of section 4(d) of the Act states that the Secretary may by regulation 
prohibit with respect to any threatened species any act prohibited 
under section 9(a)(1), in the case of fish or wildlife, or section 
9(a)(2), in the case of plants. Thus, the combination of the two 
sentences of section 4(d) provides the Secretary with wide latitude of 
discretion to select and promulgate appropriate regulations tailored to 
the specific conservation needs of the threatened species. The second 
sentence grants particularly broad discretion to the Service when 
adopting the prohibitions under section 9.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld rules 
developed under section 4(d) as a valid exercise of agency authority 
where they prohibited take of threatened wildlife, or include a limited 
taking prohibition (see Alsea Valley

[[Page 73940]]

Alliance v. Lautenbacher, 2007 U.S. Dist. Lexis 60203 (D. Or. 2007); 
Washington Environmental Council v. National Marine Fisheries Service, 
2002 U.S. Dist. Lexis 5432 (W.D. Wash. 2002)). Courts have also upheld 
4(d) rules that do not address all of the threats a species faces (see 
State of Louisiana v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted 
in the legislative history of the Act, ``once an animal is on the 
threatened list, the Secretary has an almost infinite number of options 
available to him [or her] with regard to the permitted activities for 
those species. He [or she] may, for example, permit taking, but not 
importation of such species, or he [or she] may choose to forbid both 
taking and importation but allow the transportation of such species'' 
(H.R. Rep. No. 412, 93rd Cong., 1st Sess. 1973).
    Exercising this authority under section 4(d), we have developed 
proposed rules that are designed to address the conservation needs of 
the North Feather DPS and Central Coast DPS of the foothill yellow-
legged frog. Although the statute does not require us to make a 
``necessary and advisable'' finding with respect to the adoption of 
specific prohibitions under section 9, we find that these rules as a 
whole satisfy the requirement in section 4(d) of the Act to issue 
regulations deemed necessary and advisable to provide for the 
conservation of the North Feather DPS and Central Coast DPS of the 
foothill yellow-legged frog. As discussed above under Summary of 
Biological Status and Threats, we have concluded that the North Feather 
DPS and Central Coast DPS of the foothill yellow-legged frog are likely 
to become in danger of extinction within the foreseeable future 
throughout their respective ranges primarily due to threats associated 
with altered stream hydrology, nonnative species, impacts to habitat 
(agriculture, mining, urbanization, roads, recreation), disease, 
drought, extreme floods, high-severity wildfire, and the exacerbation 
of threats from the effects of climate change. The provisions of this 
proposed 4(d) rule would promote conservation of the North Feather DPS 
and Central Coast DPS of the foothill yellow-legged frog by encouraging 
management of the species' stream habitat and landscape in ways that 
meet both resource management considerations and the conservation needs 
of the species. The provisions of this proposed rule are one of many 
tools that we would use to promote the conservation of the North 
Feather DPS and Central Coast DPS of the foothill yellow-legged frog. 
This proposed 4(d) rule would apply only if and when we make final the 
listing of the North Feather DPS and Central Coast DPS of the foothill 
yellow-legged frog as threatened species.
    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they fund, authorize, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species. In 
addition, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action which is likely to 
jeopardize the continued existence of any species proposed to be listed 
under the Act or result in the destruction or adverse modification of 
proposed critical habitat.
    If a Federal action may affect a listed species or its critical 
habitat, the responsible Federal agency (action agency) must enter into 
consultation with the Service. Examples of actions that are subject to 
the section 7 consultation process are actions on State, Tribal, local, 
or private lands that require a Federal permit (such as a permit from 
the U.S. Army Corps of Engineers under section 404 of the Clean Water 
Act, a license from the Federal Energy Regulatory Commission under the 
Federal Power Act, or a permit from the Service under section 10 of the 
Act) or that involve some other Federal action (such as funding from 
the Federal Highway Administration, Federal Aviation Administration, or 
the Federal Emergency Management Agency). Federal actions not affecting 
listed species or critical habitat--and actions on State, Tribal, 
local, or private lands that are not federally funded, authorized, or 
carried out by a Federal agency--do not require section 7 consultation.
    This obligation does not change in any way for a threatened species 
with a species-specific 4(d) rule. Actions that result in a 
determination by a Federal agency of ``not likely to adversely affect'' 
continue to require the Service's written concurrence and actions that 
are ``likely to adversely affect'' a species require formal 
consultation and the formulation of a biological opinion.

Provisions of the Proposed 4(d) Rule for the North Feather DPS and the 
Central Coast DPS of the Foothill Yellow-Legged Frog

    This proposed 4(d) rule would provide for the conservation of the 
North Feather DPS and Central Coast DPS of the foothill yellow-legged 
frog by prohibiting the following activities, except as otherwise 
authorized or permitted: Import or export; take; possession and other 
acts with unlawfully taken specimens; delivery, receipt, 
transportation, or shipment in interstate or foreign commerce in the 
course of commercial activity; or sale or offer for sale in interstate 
or foreign commerce. These prohibitions mirror those prohibitions 
afforded to endangered species under section 9(a)(1) of the Act.
    In addition to the prohibited activities identified above, we also 
provide standard and other exceptions to those prohibitions for certain 
activities as described below.
    We note that the long-term viability of the North Feather DPS and 
Central Coast DPS of the foothill yellow-legged frog, as with many 
wildlife species, is intimately tied to the condition of their habitat. 
As described in our analysis of the species' status, one of the major 
threats to the North Feather DPS and Central Coast DPS of the foothill 
yellow-legged frog's continued viability is habitat loss, degradation, 
and fragmentation resulting from past or current anthropogenic impacts 
or from catastrophic wildfires. The potential for an increase in 
frequency and severity of catastrophic wildfires from the effects of 
climate change subsequently increases the risk to the species posed by 
this threat. An additional threat is the occurrence of nonnative 
species that may predate upon and compete for resources with the 
foothill yellow-legged frog.
    We have determined that actions taken by forest management entities 
in the range of the North Feather DPS and Central Coast DPS of the 
foothill yellow-legged frog for the purpose of reducing the risk or 
severity of catastrophic wildfires and protecting stream habitat, even 
if these actions may result in some short-term or low level of 
localized negative effect to North Feather DPS and/or Central Coast DPS 
of the foothill yellow-legged frog, will further the goal of reducing 
the likelihood of either DPS becoming endangered, and will also likely 
contribute to their conservation and long-term viability. This includes 
measures approved by the Service, to conduct wildfire prevention 
activities, non-emergency suppression activities, and other 
silviculture best management practices that are in accordance with an 
established forest or fuels management plan and that include measures 
that minimize impacts to the species and its habitat.
    In addition, habitat restoration efforts that specifically provide 
for the habitat needs of the North Feather DPS and Central Coast DPS of 
the foothill yellow-legged frog as approved by the Service

[[Page 73941]]

and include measures that minimize impacts to the species and its 
habitat are appropriate for an exception. These activities would most 
likely have some limited short-term impacts but overall would provide 
for conservation of the two DPSs. Habitat restoration efforts focused 
on other species (e.g., salmonid species) are not included in this 
exception without written approval from the Service.
    Removal and restoration of trespass cannabis cultivation sites as 
approved by the Service are excepted from prohibitions. These 
activities would benefit the foothill yellow-legged frog, especially in 
the Central Coast DPS area. Trespass cannabis cultivation sites cause 
several issues for the foothill yellow-legged frog including water 
diversion, pollution, sedimentation, and introduction of pesticides and 
fertilizers to streams occupied by the foothill yellow-legged frog. 
When these sites are found, they often require reclamation (waste 
cleanup and removal of fertilizers, pesticides, and debris) and 
restoration to precultivation conditions. Cleanup of these sites may 
involve activities that may cause localized, short-term disturbance to 
the North Feather DPS and Central Coast DPS of the foothill yellow-
legged frog. However, the removal of pesticides and other chemicals 
that can affect the North Feather DPS or Central Coast DPS of the 
foothill yellow-legged frog and the surrounding environment is 
encouraged. Removal and restoration of trespass cannabis cultivation 
sites is expected to have long-term benefits for resiliency of the 
North Feather DPS and Central Coast DPS.
    Nonnative species removal would significantly increase the 
viability of the foothill yellow-legged frog. As discussed above, 
bullfrogs, nonnative fish, and nonnative crayfish contribute to 
foothill yellow-legged frog predation and increase competition for 
resources. Bullfrogs also are vectors for disease that affects the 
foothill yellow-legged frog. Actions with the primary or secondary 
purpose of removing nonnative animal species that compete with, predate 
upon, or degrade the habitat of the foothill yellow-legged frog that 
are conducted in unoccupied habitat and approved by the Service are 
provided as an exception. Large-scale actions that disrupt habitat or 
are conducted in occupied stream segments would need additional 
approval from the Service.
    Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, or collect, or to attempt to engage in any 
such conduct. Some of these provisions have been further defined in 
regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by 
direct and indirect impacts, intentionally or incidentally. Regulating 
take would help preserve the species' remaining populations, slow their 
rate of decline, and decrease synergistic, negative effects from other 
ongoing or future threats.
    We may issue permits to carry out otherwise prohibited activities, 
including those described above, involving threatened wildlife under 
certain circumstances. Regulations governing permits are codified at 50 
CFR 17.32. With regard to threatened wildlife, a permit may be issued 
for the following purposes: For scientific purposes, to enhance 
propagation or survival, for economic hardship, for zoological 
exhibition, for educational purposes, for incidental taking, or for 
special purposes consistent with the purposes of the Act. The statute 
also contains certain exemptions from the prohibitions, which are found 
in sections 9 and 10 of the Act and are included as standard exceptions 
in the proposed 4(d) rule.
    We recognize the special and unique relationship with our State 
natural resource agency partners in contributing to conservation of 
listed species. State agencies often possess scientific data and 
valuable expertise on the status and distribution of endangered, 
threatened, and candidate species of wildlife and plants. State 
agencies, because of their authorities and their close working 
relationships with local governments and landowners, are in a unique 
position to assist the Service in implementing all aspects of the Act. 
In this regard, section 6 of the Act provides that the Service shall 
cooperate to the maximum extent practicable with the States in carrying 
out programs authorized by the Act. Therefore, any qualified employee 
or agent of a State conservation agency that is a party to a 
cooperative agreement with the Service in accordance with section 6(c) 
of the Act, who is designated by his or her agency for such purposes, 
would be able to conduct activities designed to conserve the foothill 
yellow-legged frog, that may result in otherwise prohibited take, 
without additional authorization.
    Nothing in this proposed 4(d) rule would change in any way the 
recovery planning provisions of section 4(f) of the Act, the 
consultation requirements under section 7 of the Act, or the ability of 
the Service to enter into partnerships for the management and 
protection of the foothill yellow-legged frog. However, interagency 
cooperation may be further streamlined through planned programmatic 
consultations for the species between Federal agencies and the Service, 
where appropriate. We ask the public, particularly State agencies and 
other interested stakeholders that may be affected by the proposed 4(d) 
rule, to provide comments and suggestions regarding additional guidance 
and methods that the Service could provide or use, respectively, to 
streamline the implementation of this proposed 4(d) rule (see 
Information Requested, above).

III. Critical Habitat

Background

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the provisions of 
section 4 of this Act, on which are found those physical or biological 
features
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.

Prudency Determination

    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12) require that, to the maximum extent prudent 
and determinable, the Secretary shall designate critical habitat at the 
time the species is determined to be an endangered or threatened 
species. Our regulations (50 CFR 424.12(a)(1)) state that the Secretary 
may, but is not required to, determine that a designation would not be 
prudent in the following circumstances:
    (i) The species is threatened by taking or other human activity and 
identification of critical habitat can be expected to increase the 
degree of such threat to the species;
    (ii) The present or threatened destruction, modification, or 
curtailment of a species' habitat or range is not a threat to the 
species, or threats to the species' habitat stem solely from causes 
that cannot be addressed through management actions resulting from 
consultations under section 7(a)(2) of the Act;
    (iii) Areas within the jurisdiction of the United States provide no 
more than negligible conservation value, if any, for a species 
occurring primarily outside the jurisdiction of the United States;

[[Page 73942]]

    (iv) No areas meet the definition of critical habitat; or
    (v) The Secretary otherwise determines that designation of critical 
habitat would not be prudent based on the best scientific data 
available.
    As discussed earlier in this document, we did not identify an 
imminent threat of collection or vandalism identified under Factor B 
for this species, and identification and mapping of critical habitat is 
not expected to initiate any such threat. In our SSA report and this 
proposed listing determination for the four DPSs of the foothill 
yellow-legged frog, we determined that the present or threatened 
destruction, modification, or curtailment of habitat or range (Factor 
A) is a threat to the four DPSs and that the Factor A threats in some 
way can be addressed by the Act's section 7(a)(2) consultation 
measures. The four DPSs occur wholly in the jurisdiction of the United 
States, and we are able to identify areas that meet the definition of 
critical habitat. Therefore, because none of the circumstances 
enumerated in our regulations at 50 CFR 424.12(a)(1) have been met and 
because the Secretary has not identified other circumstances for which 
this designation of critical habitat would be not prudent, we have 
determined that the designation of critical habitat is prudent for the 
four DPSs of the foothill yellow-legged frog.

Critical Habitat Determinability

    Having determined that designation is prudent, under section 
4(a)(3) of the Act we must find whether critical habitat for the four 
DPSs of the foothill yellow-legged frog is determinable. Our 
regulations at 50 CFR 424.12(a)(2) state that critical habitat is not 
determinable when one or both of the following situations exist:
    (i) Data sufficient to perform required analyses are lacking, or
    (ii) The biological needs of the species are not sufficiently well 
known to identify any area that meets the definition of ``critical 
habitat.''
    When critical habitat is not determinable, the Act allows the 
Service an additional year to publish a critical habitat designation 
(16 U.S.C. 1533(b)(6)(C)(ii)).
    We reviewed the available information pertaining to the biological 
needs of the four DPSs of the foothill yellow-legged frog and habitat 
characteristics where the four DPSs are located. A careful assessment 
of the economic impacts that may occur due to a critical habitat 
designation is still ongoing, and we are in the process of working with 
the State and other partners in acquiring the complex information 
needed to perform that assessment. Therefore, due to the current lack 
of data sufficient to perform required analyses, we conclude that the 
designation of critical habitat for the four DPSs of the foothill 
yellow-legged frog is not determinable at this time. The Act allows the 
Service an additional year to publish a critical habitat designation 
that is not determinable at the time of listing (16 U.S.C. 
1533(b)(6)(C)(ii)).

Required Determinations

Clarity of the Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help us 
revise the rule, your comments should be as specific as possible. For 
example, you should tell us the numbers of the sections or paragraphs 
that are unclearly written, which sections or sentences are too long, 
the sections where you feel lists or tables would be useful, etc.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be 
prepared in connection with regulations adopted pursuant to section 
4(a) of the Act. We published a notice outlining our reasons for this 
determination in the Federal Register on October 25, 1983 (48 FR 
49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. We solicited information from all of 
the Tribes within the entire range of the foothill-yellow-legged frog 
to inform the development of the SSA report, and we notified Tribes of 
our upcoming proposed listing determination. We also provided these 
Tribes the opportunity to review a draft of the SSA report and provide 
input prior to making our proposed determination on the status of the 
foothill yellow-legged frog, but we did not receive any responses. We 
will continue to coordinate with Tribal entities throughout the listing 
process for the foothill yellow-legged frog.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at https://www.regulations.gov and upon request from the 
Sacramento Fish and Wildlife Office (see FOR FURTHER INFORMATION 
CONTACT).

Authors

    The primary authors of this proposed rule are the staff members of 
the Fish and Wildlife Service's Species Assessment Team and Field 
Office staff within the range of the species in California and Oregon.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:


    Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless 
otherwise noted.

0
2. Amend Sec.  17.11(h) by adding entries for ``Frog, foothill yellow-
legged

[[Page 73943]]

[Central Coast DPS]'', ``Frog, foothill yellow-legged [North Feather 
DPS]'', ``Frog, foothill yellow-legged [South Coast DPS]'', and ``Frog, 
foothill yellow-legged [South Sierra DPS]'' to the List of Endangered 
and Threatened Wildlife in alphabetical order under AMPHIBIANS to read 
as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                              Listing citations
           Common name               Scientific name        Where listed         Status         and applicable
                                                                                                    rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
                                                   Amphibians
 
                                                  * * * * * * *
Frog, foothill yellow-legged       Rana boylii........  California (All      T               [Federal Register
 [Central Coast DPS].                                    foothill yellow-                     citation when
                                                         legged frogs in                      published as a
                                                         the Central Coast                    final rule]; 50
                                                         Range south of San                   CFR 17.43(g).\4d\
                                                         Francisco Bay to
                                                         San Benito and
                                                         Fresno Counties).
Frog, foothill yellow-legged       Rana boylii........  California (All      T               [Federal Register
 [North Feather DPS].                                    foothill yellow-                     citation when
                                                         legged frogs in                      published as a
                                                         the North Feather                    final rule]; 50
                                                         River watershed                      CFR 17.43(g).\4d\
                                                         largely in Plumas
                                                         and Butte
                                                         Counties).
Frog, foothill yellow-legged       Rana boylii........  California (All      E               [Federal Register
 [South Coast DPS].                                      foothill yellow-                     citation when
                                                         legged frogs in                      published as a
                                                         the Coast Range                      final rule].
                                                         from Coastal
                                                         Monterey County
                                                         south to Los
                                                         Angeles County).
Frog, foothill yellow-legged       Rana boylii........  California (All      E               [Federal Register
 [South Sierra DPS].                                     foothill yellow-                     citation when
                                                         legged frogs in                      published as a
                                                         the Sierra Nevada                    final rule].
                                                         Mountains south of
                                                         the American River
                                                         sub-basin south to
                                                         the Transverse
                                                         Range in Kern
                                                         County).
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

0
3. Amend Sec.  17.43 by adding a paragraph (g) to read as set forth 
below:


Sec.  17.43  Special rules--amphibians

* * * * *
    (g) Foothill yellow-legged frog (Rana boylii), Central Coast 
Distinct Population Segment (DPS) and North Feather DPS.
    (1) Location. The Central Coast DPS and North Feather DPS of the 
foothill yellow-legged frog are shown on the map that follows:
BILLING CODE 4333-15-P

[[Page 73944]]

[GRAPHIC] [TIFF OMITTED] TP28DE21.020

    (2) Prohibitions. The following prohibitions that apply to 
endangered wildlife also apply to the Central Coast DPS and North 
Feather DPS of the foothill yellow-legged frog. Except as provided 
under paragraph (g)(3) of this section and Sec. Sec.  17.4 and 17.5, it 
is unlawful for any person subject to the jurisdiction of the United 
States to commit, to attempt to commit, to solicit another to commit, 
or cause to be committed, any of the following acts in regard to this 
species:
    (i) Import or export, as set forth at Sec.  17.21(b) for endangered 
wildlife.
    (ii) Take, as set forth at Sec.  17.21(c)(1) for endangered 
wildlife.
    (iii) Possession and other acts with unlawfully taken specimens, as 
set forth at Sec.  17.21(d)(1) for endangered wildlife.
    (iv) Interstate or foreign commerce in the course of commercial 
activity, as set forth at Sec.  17.21(e) for endangered wildlife.
    (v) Sale or offer for sale, as set forth at Sec.  17.21(f) for 
endangered wildlife.
    (3) Exceptions from prohibitions. In regard to the Central Coast 
DPS and North Feather DPS of the foothill yellow-legged frog, you may:
    (i) Conduct activities as authorized by a permit under Sec.  17.32.
    (ii) Take, as set forth at Sec.  17.21(c)(2) through (c)(4) for 
endangered wildlife.
    (iii) Take as set forth at Sec.  17.31(b).
    (iv) Take incidental to an otherwise lawful activity caused by:
    (A) Forest management activities as approved by the Service for the 
purposes of reducing the risk or severity of catastrophic wildfire, 
which include fuels reduction activities, non-emergency firebreak 
establishment or maintenance, and other non-emergency wildfire 
prevention and suppression activities that are in accordance with an 
established forest or fuels management plan and that include measures 
that minimize impacts to the species and its stream habitat.

[[Page 73945]]

    (B) Habitat restoration efforts as approved by the Service that are 
specifically designed to provide for the conservation of the foothill 
yellow-legged frog's habitat needs and include measures that minimize 
impacts to the species and its habitat as approved by the Service. 
Habitat restoration efforts for other species that may not share 
habitat requirements (e.g., salmonid species) are not included in this 
exception unless approved by the Service.
    (C) Efforts as approved by the Service to remove and clean up 
trespass cannabis cultivation sites and related water diversion 
infrastructure and restore areas to precultivation conditions.
    (D) Removal or eradication of nonnative animal species including, 
but not limited to, American bullfrogs, smallmouth bass, and nonnative 
crayfish species occurring within stream reaches unoccupied by the 
foothill yellow-legged frog within the range of the Central Coast DPS 
or North Feather DPS as approved by the Service.
    (v) Possess and engage in other acts with unlawfully taken 
wildlife, as set forth at Sec.  17.21(d)(2) for endangered wildlife.

Martha Williams,
Principal Deputy Director, Exercising the Delegated Authority of the 
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2021-27512 Filed 12-27-21; 8:45 am]
BILLING CODE 4333-15-C