Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad (Anaxyrus californicus), 52612-52664 [E9-24076]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 74, Number 196 (Tuesday, October 13, 2009)]
[Proposed Rules]
[Pages 52612-52664]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-24076]



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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; Revised Critical Habitat 
for the Arroyo Toad (Anaxyrus californicus); Proposed Rule

Federal Register / Vol. 74, No. 196 / Tuesday, October 13, 2009 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2009-0069; 92210-1117-0000-B4]
RIN 1018-AV89


Endangered and Threatened Wildlife and Plants; Revised Critical 
Habitat for the Arroyo Toad (Anaxyrus californicus)

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 
revise designated critical habitat for the arroyo toad (Anaxyrus 
californicus), pursuant to the Endangered Species Act of 1973, as 
amended (Act). The previous final rule designated 11,695 acres (ac) 
(4,733 hectares (ha)) of critical habitat and was published in the 
Federal Register (FR) on April 13, 2005. We now propose to designate 
approximately 109,110 ac (44,155 ha) of lands located in Santa Barbara, 
Ventura, Los Angeles, San Bernardino, Riverside, Orange, and San Diego 
Counties, California, which, if finalized as proposed, would result in 
an increase of approximately 97,415 ac (39,422 ha) of critical habitat.

DATES: We will consider comments we receive on or before December 14, 
2009. We must receive requests for public hearings, in writing, at the 
address shown in the FOR FURTHER INFORMATION CONTACT section by 
November 27, 2009.

ADDRESSES: You may submit comments by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the instructions for submitting comments to Docket No. FWS-R8-
ES-2009-0069.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R8-ES-2009-0069, Division of Policy and Directives 
Management, U.S. Fish and Wildlife Service, 4401 N. Fairfax Drive, 
Suite 222, Arlington, VA 22203.
    We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: For general information on the 
proposed designation and information about the proposed revised 
designation in Santa Barbara and Ventura Counties, northern Los Angeles 
County, and the desert portion of San Bernardino County, contact Diane 
Noda, Field Supervisor, or Michael McCrary, Listing and Recovery 
Coordinator, Ventura Fish and Wildlife Office, U.S. Fish and Wildlife 
Service, 2493 Portola Road, Suite B, Ventura, CA 93003; telephone (805) 
644-1766; facsimile (805) 644-3958.
    For information about the proposed revised designation in the 
remaining portions of Los Angeles and San Bernardino Counties, as well 
as Riverside, Orange, and San Diego Counties, contact Jim Bartel, Field 
Supervisor, Carlsbad Fish and Wildlife Office, U.S. Fish and Wildlife 
Service, 6010 Hidden Valley Road, Suite 101, Carlsbad, CA 92011; 
telephone (760) 431-9440; facsimile (760) 431-9624.
    If you use a telecommunications device for the deaf (TDD), call the 
Federal Information Relay Service (FIRS) at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

    We intend any final action resulting from this proposed revised 
rule to be 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 the public, other government agencies, 
Tribes, the scientific community, industry, or other interested parties 
concerning this proposed rule. We particularly seek comments 
concerning:
    1. The reasons why we should or should not revise the designation 
of habitat as ``critical habitat'' under section 4 of the Endangered 
Species Act of 1973, as amended (Act; 16 U.S.C. 1531 et seq.), 
including whether there are threats to the species from human activity, 
the degree of which can be expected to increase due to the designation, 
and whether that increase in threat outweighs the benefit of 
designation such that the designation of critical habitat is not 
prudent;
    2. Specific information on:
     The amount and distribution of arroyo toad habitat 
included in this proposed revised rule,
     What areas within the geographical area occupied by the 
species at the time of listing contain features essential to the 
conservation of the species and why, and
     What areas outside the geographical area occupied by the 
species at the time of listing are essential for the conservation of 
the species and why;
    3. Land-use designations and current or planned activities in the 
subject areas and their possible effects on proposed revised critical 
habitat;
    4. Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation. We are particularly interested in any impacts on small 
entities, and the benefits of including or excluding areas that exhibit 
these impacts;
    5. Comments or information that may assist us in identifying or 
clarifying the primary constituent elements and the resulting physical 
and biological features essential to the conservation of the arroyo 
toad;
    6. How the proposed revised critical habitat boundaries could be 
refined to more closely circumscribe the landscapes identified as 
essential;
    7. Information regarding Trabuco Creek in Orange County and any 
special management considerations or protection that any essential 
physical or biological features in this area may require;
    8. Information regarding the San Diego River in San Diego County 
from just below El Capitan Reservoir downstream to the confluence with 
San Vicente Creek, and any special management considerations or 
protection that any essential physical or biological features in this 
area may require;
    9. Whether the potential exclusion under section 4(b)(2) of the Act 
of non-Federal lands covered by the Western Riverside County Multiple 
Species Habitat Conservation Plan from final revised critical habitat 
is or is not appropriate and why;
    10. Whether the potential exclusion under section 4(b)(2) of the 
Act of non-Federal lands covered by the San Diego Multiple Species 
Conservation Program-City and County of San Diego's Subarea Plans from 
final revised critical habitat is or is not appropriate and why;
    11. Whether the potential exclusion under section 4(b)(2) of the 
Act of non-Federal lands covered by the Coachella Valley Multiple 
Species Habitat Conservation Plan from final revised critical habitat 
is or is not appropriate and why;
    12. Whether the potential exclusion under section 4(b)(2) of the 
Act of non-Federal lands covered by the Orange County Central-Coastal 
Subregional Habitat Conservation Plan/Natural Community Conservation 
Plan from final revised critical habitat is or is not appropriate and 
why;
    13. Whether the potential exclusion under section 4(b)(2) of the 
Act of non-Federal lands covered by the Southern Orange County Natural 
Community Conservation Plan/Master Streambed Alteration Agreement/
Habitat Conservation Plan from final revised critical habitat is or is 
not appropriate and why;

[[Page 52613]]

    14. Whether the conservation needs of the arroyo toad can be 
achieved or not by limiting the designation of final revised critical 
habitat to non-Tribal lands and why;
    15. Whether the potential exclusion under section 4(b)(2) of the 
Act of Tribal lands of the Rincon Band of Luise[ntilde]o Mission 
Indians from final revised critical habitat is or is not appropriate 
and why;
    16. Whether the potential exclusion under section 4(b)(2) of the 
Act of Tribal lands of the Pala Band of Luise[ntilde]o Mission Indians 
from final revised critical habitat is or is not appropriate and why;
    17. Whether the potential exclusion under section 4(b)(2) of the 
Act of Tribal lands of the Sycuan Band of the Kumeyaay Nation from 
final revised critical habitat is or is not appropriate and why;
    18. Whether the potential exclusion under section 4(b)(2) of the 
Act of Tribal lands of the Capitan Grande Band of Diegueno Mission 
Indians from final revised critical habitat is or is not appropriate 
and why;
    19. Whether the potential exclusion under section 4(b)(2) of the 
Act of Tribal lands of the Mesa Grande Band of Diegueno Mission Indians 
from final revised critical habitat is or is not appropriate and why;
    20. Whether our exemption under section 4(a)(3)(B) of the Act of 
the lands on Department of Defense land at Marine Corps Base, Camp 
Pendleton, in San Diego County; Fallbrook Naval Weapons Station in San 
Diego County; and Fort Hunter Liggett Military Reservation in San Luis 
Obispo County is or is not appropriate, and why;
    21. Information on any quantifiable economic costs or benefits of 
the proposed revised designation of critical habitat;
    22. Whether the benefit of exclusion of any other particular area 
not specifically identified above outweighs the benefit of inclusion 
under section 4(b)(2) of the Act;
    23. Information on the currently predicted effects of climate 
change on the arroyo toad and its habitat;
    24. Any foreseeable impacts on energy supplies, distribution, and 
use resulting from the proposed revised designation and, in particular, 
any impacts on electricity production, and the benefits of including or 
excluding any particular areas that exhibit these impacts; and
    25. Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    Our final determination concerning revised critical habitat for the 
arroyo toad will take into consideration all written comments received 
during the comment period, including comments requested from peer 
reviewers, comments received during a public hearing should one be 
requested, and any additional information we receive during the 60-day 
comment period. Our final determination will also consider all written 
comments and any additional information we receive during the comment 
period for the draft economic analysis. All comments will be included 
in the public record for this rulemaking. On the basis of peer reviewer 
and public comments, we may, during the development of our final 
determination, find that areas within those proposed do not meet the 
definition of critical habitat, that some modifications to the 
described boundaries are appropriate, or that areas are or are not 
appropriate for exclusion under section 4(b)(2) of the Act.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section.
    We will post your entire comment--including your personal 
identifying information--on https://www.regulations.gov. If you provide 
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 comments on https://www.regulations.gov. Please include 
sufficient information with your comment to allow us to verify any 
scientific or commercial data you submit.
    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, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Ventura Fish and Wildlife Office (see FOR FURTHER 
INFORMATION CONTACT).
    You may obtain copies of the proposed revised rule by mail from the 
Ventura Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT) 
or by visiting the Federal eRulemaking Portal at https://www.regulations.gov.

Background

    It is our intent to discuss only those topics directly relevant to 
the revised designation of critical habitat in this proposed rule. 
Additional information on the arroyo toad may also be found in the 
final listing rule published in the Federal Register on December 16, 
1994 (59 FR 64859), the ``Recovery Plan for the Arroyo Southwestern 
Toad'' (recovery plan; Service 1999), and the designation of critical 
habitat for the arroyo toad published in the Federal Register on April 
13, 2005 (70 FR 19562). These documents are available on the Ventura 
Fish and Wildlife Office and Carlsbad Fish and Wildlife Office Web 
sites at https://www.fws.gov/ventura and https://www.fws.gov/carlsbad. 
However, please note that this proposed rule incorporates new 
information on the distribution of arroyo toads that became available 
since the 2005 final critical habitat designation for this species.

Taxonomy and Nomenclature

    On December 16, 1994, we published a final rule listing the arroyo 
southwestern toad (Bufo microscaphus californicus) as endangered (59 FR 
64859). This animal, originally described as Bufo cognatus californicus 
(Camp 1915, p. 331), has consistently been treated as a distinct taxon. 
However, its rank as a subspecies or species and taxonomic affiliations 
with other species has changed several times since it was described. 
Myers (1930, p. 75) elevated it to species rank as Bufo californicus 
citing morphological, vocalization, and ecological data to distinguish 
it from B. cognatus. Subsequent to Myers' paper, other authors again 
relegated the animal to subspecies rank aligned with various other 
species of Bufo. The name in use at the time of listing, Bufo 
microscaphus californicus, was published by Stebbins (1951, p. 275).
    Since the toad was listed, an analysis of allozyme data (Gergus 
1998, p. 322) supports recognition of Bufo californicus as separate 
from B. microscaphus. In addition, a phylogenetic analysis of 
comparative anatomical and molecular genetic data for amphibians (Frost 
et al. 2006, p. 363) segregated the Nearctic taxa of Bufo as the genus 
Anaxyrus and published the combination Anaxyrus californicus, the 
arroyo toad. This treatment is accepted by the Committee on Standard 
English and Scientific Names of the American Society of Ichthyologists 
and Herpetologists, The Herpetologists' League, and the Society for the 
Study of Amphibians and Reptiles (Frost et al. 2008, p. 3).
    In light of these changes and their acceptance by the above 
scientific authorities, we are proposing to amend the List of 
Threatened and Endangered Wildlife at 50 CFR 17.11 to identify the

[[Page 52614]]

listed entity as ``arroyo toad (Anaxyrus californicus).'' This change 
does not alter the description or distribution of the animals.

Species Description

    The arroyo toad is a small, dark-spotted toad of the family 
Bufonidae. Its coloration ranges from light olive green or gray to 
light brown with a distinctive light-colored, V-shaped stripe across 
the head and the eyelids. The belly is white or buff and often lacks 
dark blotches or spots (Stebbins 2003, p. 212). The species is endemic 
to the coastal plain and mountains of central and southern California, 
and northwestern Baja California, Mexico, from near sea level to about 
8,000 feet (ft) (2,440 meters (m)) in elevation. For a detailed 
description of the species, see the recovery plan and references cited 
within the plan (Service 1999, pp. 1-119), and information in previous 
Federal Register notices, proposed rules, and final rules (59 FR 64859, 
December 16, 1994; 66 FR 9414, February 7, 2001; 69 FR 23254, April 28, 
2004; 70 FR 19562, April 13, 2005). In addition to the recovery plan, 
important sources for information on the biology of the arroyo toad 
include: Sweet (1992, pp. 1-198; 1993, pp. 1-73); Campbell et al. 
(1996, pp. 1-46); Griffin et al. (1998, pp. 1-66); Griffin and Case 
(2001, pp. 633-644); Holland and Sisk (2001); and Ramirez (2002a, pp. 
1-62; 2002b; 2002c; 2003, pp. 1-101).

Life History

    Breeding typically occurs from February to July on streams with 
persistent water (Griffin et al. 1999, p. 1). Males may breed with 
several females in a season; however, female arroyo toads release their 
entire clutch of eggs as a single breeding effort and probably do not 
produce a second clutch during the mating season. Eggs are deposited 
and tadpoles develop in shallow pools with minimal current and little 
or no emergent vegetation. The substrate in these pools is generally 
sand or fine gravel overlain with silt. The eggs hatch in 4 to 5 days 
and the tadpoles are immobile for an additional 5 to 6 days. Tadpoles 
then begin to disperse from the pool margin into the surrounding 
shallow water, where they spend an average of 10 weeks. Peak 
metamorphosis occurs during June and July in the northern part of the 
arroyo toad's range, and from late April through June farther south, 
although it could occur later, particularly at higher elevations 
(Holland 2000, in litt. p. 8). After metamorphosis, the juvenile arroyo 
toads remain on the bordering gravel bars until the pool dries out 
(usually from 8 to 12 weeks depending on the site and rainfall). Most 
individuals become sexually mature by the following spring (Sweet 1992, 
p. 52).
    Arroyo toad tadpoles feed on loose organic material such as 
interstitial algae, bacteria, and diatoms. They do not forage on 
macroscopic vegetation (Sweet 1992, p. 82; Jennings and Hayes 1994, p. 
56). Juvenile arroyo toads feed on ants almost exclusively (Service 
1999, p. 36). By the time they reach 0.7 to 0.9 inch (in) (1.78 
centimeters (cm)) in length, they consume beetles along with ants 
(Sweet 1992, p. 99; Service 1999, p. 36). Adult arroyo toads probably 
consume a wide variety of insects and arthropods including (but not 
limited to) ants, beetles, spiders, larvae, and caterpillars.

Geographic Range

    The historical and current range of the arroyo toad extends from 
the Salinas River Basin southward through the Santa Ynez, Santa Clara, 
and Los Angeles River basins (Sweet 1992, p. 18), to Orange, Riverside, 
and San Diego Counties (Jennings and Hayes 1994, p. 54) and southward 
to the Arroyo San Simeon system, Baja California, Mexico (Service 1999, 
p. 12; Ramirez 2007, p. 5). Populations also occur on the desert slopes 
of both the San Gabriel Mountains (in Little Rock Creek in Los Angeles 
County) and the San Bernardino Mountains (in the Mojave River and in 
its tributaries, Little Horsethief and Deep Creeks, in San Bernardino 
County) (Sweet 1992, p. 18; Jennings and Hayes 1994, p. 54).
    At the time of listing (59 FR 64859; December 16, 1994), arroyo 
toads were believed to be extirpated from the Salinas River Basin. In 
1996, arroyo toads were found during surveys on the Fort Hunter Liggett 
Military Reservation approximately 40 miles (mi) (64 kilometers (km)) 
downstream of the historical Santa Margarita arroyo toad locality (U.S. 
Army Reserve 2004, pp. 5-10). In 1997, arroyo toads were detected along 
a 17-mi (27-km) stretch of the San Antonio River. The Army surveyed 
approximately 6 mi (9.6 km) of the San Antonio River on the Military 
Reservation in 2002 and estimated there were as many as 7,000 arroyo 
toad larvae (tadpoles) in the area (U.S. Army Reserve Command 2004, p. 
12). We believe this population was present but undetected on Fort 
Hunter Liggett at the time of listing for the following reasons: (1) 
Annual surveys (U.S. Army Reserve 2004, p. 38) indicate there is 
suitable breeding and upland habitats for this large, robust 
population; and (2) given that the nearest extant population of arroyo 
toads is 150 mi (240 km) southeast of Fort Hunter Liggett in Santa 
Barbara County, it is unlikely that arroyo toads could have dispersed 
and newly colonized the Fort Hunter Liggett area by 1996, just 2 years 
subsequent to the species being listed in 1994. Therefore, we consider 
the population on Fort Hunter Liggett to have existed in 1994 and to 
represent the northernmost limit of the species' range at listing and 
currently. The geographical area occupied by the species at the time it 
was listed is the same as the species' current range in the coastal 
streams extending from Monterey County southward to San Diego County, 
and extending eastward into the riparian (along the shore of a river, 
stream, or lake) environments of San Bernardino and Riverside Counties.
    Arroyo toads have been extirpated from approximately 75 percent of 
the habitat they originally occupied (Sweet 1992, p. 189; Jennings and 
Hayes 1994, p. 57; Campbell et al. 1996, p. 2). At present, arroyo 
toads are limited to isolated populations primarily in the headwaters 
of coastal streams. The species is likely restricted naturally as a 
result of specific habitat requirements for breeding and development 
(Service 1999, p. 39). These natural restrictions, coupled with the 
small sizes of many arroyo toad populations, make them particularly 
vulnerable to the negative effects of human-induced changes to their 
habitat (Jennings and Hayes 1994, p. 57).

Habitat

    Stream order, elevation, and floodplain width appear to be 
important factors in determining habitat suitability (Sweet 1992, pp. 
24-26; Griffin et al. 1999, pp. 1-3). Stream order ranks the size and 
potential power of streams. The smallest channels in a watershed with 
no tributaries are referred to as first-order streams. When two first-
order streams unite, they form a second-order stream; when two second-
order streams unite, they form a third-order stream, and so on. Fifth- 
and sixth-order streams are usually larger rivers, while first- and 
second-order streams are often small, steep, or intermittent. In the 
northern portion of the range, arroyo toads are found on third- to 
sixth-order streams (Sweet 1992, p. 24), while in the central and 
southern portion of the range, arroyo toads are found in first- to 
sixth-order streams (Service 1999, p. 32).
    Optimal breeding habitat consists of low-gradient sections of slow-
moving streams with shallow pools, nearby sandbars, and adjacent stream 
terraces. Arroyo toads breed and deposit egg masses in the shallow, 
sandy pools of these streams, which are usually

[[Page 52615]]

bordered by sand-gravel flood-terraces. Breeding sites favored by adult 
arroyo toads have clear water in shallow (less than 12 in (30 cm) deep) 
pools (Sweet 1992, p. 28). Optimal breeding sites also have flow rates 
less than 1.97 in (5 cm) per second and bottoms composed of sand or 
well-sorted, fine gravel, although a significant component of large 
gravel or cobble may also be present (Sweet 1992, p. 37).
    Stream terrace habitat consisting of alluvial bars and terraces 
that may have established cottonwoods (Populus spp.), oaks (Quercus 
spp.), or willows (Salix spp.) and almost no grass and herbaceous cover 
at ground level are extremely important for arroyo toads prior to, 
during, and after the breeding season (Griffin et al. 1999, p. 45; 
Sweet 1992, pp. 28-49). Areas that are used by juveniles consist 
primarily of sand or fine gravel bars with varying amounts of large 
gravel or cobble and adjacent stable sandy terraces and oak flats. 
Juvenile arroyo toads favor areas that are damp and have some 
vegetation cover (less than 10 percent), which offer refugia and 
thermal characteristics that are needed for juvenile survival and rapid 
growth (Campbell et al. 1996, p. 12). Bare sand and gravel bars may 
support large numbers of juvenile toads, but survivorship can be 
reduced due to high levels of predation (Sweet 1992, p. 113).
    Adult arroyo toads are often found on sandy alluvial terraces 
adjacent to the stream that may be sparsely-to-heavily vegetated with 
brush and trees, such as mulefat (Baccharis spp.), California sycamore 
(Platanus racemosa), cottonwoods, coast live oak (Quercus agrifolia), 
and willow (Campbell et al. 1996, pp. 12-13). The understory of stream 
terraces may consist of scattered short grasses, herbs, and leaf 
litter, with patches of bare or disturbed soil, or have no vegetation 
at all. When foraging, juvenile and adult arroyo toads are often found 
around the drip lines of oak trees (Sweet 1992, pp. 45-46; Campbell et 
al. 1996, p. 10). When active at night, arroyo toads can often be 
observed near ant trails feeding on passing ants and other prey.
    Upland habitats used by arroyo toads during both the breeding and 
non-breeding seasons include alluvial scrub, coastal sage scrub, 
chaparral (shrubby plants adapted to dry summers and moist winters), 
grassland, and oak woodland. Within terrace and upland habitats, arroyo 
toads aestivate (a state of dormancy similar to hibernation) in burrows 
during the non-breeding season, which usually starts in the late summer 
and extends from August to January (Ramirez 2003, p. 46). In habitat 
utilization studies conducted by Ramirez (2007, pp. 11-14) from 1999 to 
2006 in the West Fork Mojave River and Grass Valley Creek areas, arroyo 
toads were generally found burrowed within sandy or loamy substrates 
with no associated canopy cover, or within mulefat scrub or arroyo 
willow (Salix lasiolepis) patches. The majority of individuals tracked 
in these studies burrowed immediately adjacent to the active channel or 
on sandy terraces within riparian habitat located within flood-prone 
areas; however, toads were also found to use upland habitats up to 
1,063 ft (324 m) from the active channel (Ramirez 2007, p. 13). In his 
2005 study, Ramirez (2007, p. 93) observed several arroyo toad 
individuals burrowed in stable terrace habitats dominated by Great 
Basin sage scrub and Utah junipers (Juniperus osteosperma). At Little 
Rock Creek on the desert slopes of the San Gabriel Mountains, arroyo 
toads burrowed in areas closest to the creek that retained higher soil 
saturation and were cooler (Ramirez 2002a, p. 50). Griffin et al. 
(1999, p. 45) noted that sands are the preferred burrowing substrate 
for both male and female arroyo toads, confirming the importance of 
natural hydrologic regimes that maintain sand and fine sediment 
deposition across the floodplain.

Dispersal

    Arroyo toad movement patterns also vary between watersheds or river 
reaches in response to different hydrological regimes (Griffin et al. 
1999, p. 11). In broad floodplain river systems, arroyo toads searching 
for suitable egg-laying sites may have to move across parallel stream 
channels. Cristianitos Creek, Talega Creek, and the lower San Mateo 
River are examples of this type of river system because of their wide, 
sandy floodplains where the river flows into several channels during 
floods. Despite river depths of 24 in (60 cm) and swift currents, 
Griffin et al. (1999, p. 21) observed numerous toads crossing Talega 
Creek and the lower San Mateo River, confirming these river systems are 
not a barrier to arroyo toad dispersal. In their study of arroyo toad 
movement patterns, Griffin et al. (1999, pp. 18-21) tracked 10 female 
and 3 male arroyo toads in the lower San Mateo River and observed 
female arroyo toads regularly using riparian and upland habitats far 
from the river's edge and returning to these areas after traveling far 
upstream for egg-laying. In one case, a female arroyo toad traveled 919 
ft (280 m) across the San Mateo Campground into upland native habitat; 
in another instance, a female was found 558 ft (170 m) from the San 
Mateo River under cover of mulefat scrub (Griffin et al. 1999, p. 20). 
They also recorded arroyo toads moving in both up- and downstream 
directions, such as the female arroyo toad that traveled upstream more 
than 492 ft (150 m) in a single night to a breeding pool. The study 
found that both male and female arroyo toads moved more into upland 
habitats after completing individual breeding activity (Griffin et al. 
1999, p. 46).
    In contrast, arroyo toads searching for breeding pools in 
watersheds with relatively narrower, steeper-sided drainages (such as 
the Piru and Sespe Creek Watersheds in Ventura County) tend to move in 
both up- and downstream directions along these channels with their 
structure of alternating riffles and pools (Griffin et al. 1999, p. 
11). In his Mono Creek study, Sweet (1993, pp. 24-65), concluded that 
female arroyo toads became relatively sedentary as they matured whereas 
males tended to travel up- and downstream fairly often during the 
breeding season (Sweet 1993, p. 65). This study also suggested that 
most juvenile arroyo toads disperse away from their natal pools about a 
year after metamorphosis (Sweet 1993, p. 65). In fact, numerous 
juvenile and adult arroyo toads were observed moving up- and downstream 
as much as 0.5 mi (0.8 km) and over 0.6 mi (1 km) in some cases (Sweet 
1993, p. 1). Arroyo toads in these watersheds also travel laterally 
away from the stream channel into terrace and upland native habitats. 
On lower Piru Creek, Sweet (1992, pp. 42-45) observed two adult males 
under oaks that were 200 ft (61 m) away.

Reasons for Decline and Threats

    A variety of factors contribute to the decline of arroyo toads but 
nearly half of historical extirpations prior to listing are attributed 
to dam building and operation (Sweet 1992, pp. 4-5; Ramirez 2003, p. 
7). Suitable habitat is often flooded out by reservoir water, and 
downstream breeding and non-breeding habitat may be severely altered by 
reduced flows at some times and sudden excessive flows at others. 
Sudden excessive releases of water may destroy sand bars used during 
the breeding season, and reconfigure or destroy suitable breeding 
pools, thus disrupting clutch and larval development (Ramirez 2003, p. 
7). Additionally, dams can interrupt the scouring and deposition 
processes needed to maintain arroyo toad pool and terrace habitats. 
Areas below dams can become unsuitable as fine sands are lost and not 
replaced (Service 1999, pp. 42-43).

[[Page 52616]]

    In addition to flood control projects, other threats include 
agriculture; sand and gravel mining; urban development; off-highway 
vehicle use; urbanization; recreational activities such as camping, 
fishing, hiking, picnicking; and natural factors, including drought and 
fire (59 FR 64859; Service 1999, p. 39; Ramirez 2003, p. 7). Conversion 
of stream terrace habitat for farming, road construction, and 
residential and commercial uses has eliminated substantial arroyo toad 
habitat in some areas. Suction dredge mining of sand and gravel causes 
substantial alteration of habitat by degrading water quality, altering 
stream morphology, increasing siltation downstream, and creating deep 
pools that hold water year-round for introduced predators of arroyo 
toad eggs and larvae (Campbell et al. 1996, p. 16). Natural 
disturbances, such as drought and fire, also threaten the arroyo toad 
(Campbell et al. 1996, p. 17). Prolonged drought can result in the loss 
of suitable breeding pools, foraging habitat, and prey availability 
(Sweet 1992, p. 190). Fire can affect arroyo toads by causing direct 
mortality and destruction of stream or terrace vegetation.
    The introduction of nonnative species that compete for resources or 
that prey on arroyo toads also poses a serious threat to arroyo toad 
existence. The introduction of aquatic species not native to southern 
California watercourses has been facilitated by construction of the 
California Aqueduct and other sources of inter-basin water transport 
(Service 1999, p. 48). Currently, the California Aqueduct is linked 
directly to the Santa Ynez River, Santa Clara River, San Jacinto River, 
and Mojave River Basins. Predatory species, many of which have used the 
aqueduct to colonize these river basins, include green sunfish (Lepomis 
cyanellus), largemouth bass (Micropterous salmoides), black bullhead 
(Ictalurus nebulosus), prickly sculpin (Cottus asper), stocked rainbow 
trout (Oncorhynchus mykiss), oriental gobies (Tridentiger spp.), red 
shiners (Notropis lutrensis), bullfrogs (Rana catesbeiana), African 
clawed frogs (Xenopus laevis), and crayfish (Procambarus clarkii) 
(Sweet 1992, pp. 118-122; Service 1999, p. 48). All of these species 
prey on arroyo toad tadpoles.
    Of the above introduced-predators, bullfrogs are probably the most 
serious threat to arroyo toads (Stephenson and Calcarone 1999, p. 82). 
Bullfrogs are well adapted to deep water conditions in ponded areas 
above dams, and dam releases can introduce them to downstream habitats 
(CDFG 2005, p. 178). A broad diet and an extended breeding season give 
bullfrogs a competitive advantage over native amphibians. Whereas 
arroyo toad breeding habitat requirements are highly specialized, in 
that they require shallow, slow-moving streams and riparian habitats 
that are disturbed on a regular basis, bullfrogs can tolerate elevated 
water temperatures and make use of standing pools resulting from urban 
runoff to complete their 2-year life cycle (CDFG 2005, p. 178).
    Introduced plants have also had a negative effect on arroyo toads 
and their habitat. Nonnative plant species, particularly tamarisk 
(Tamarix spp.) and giant reed (Arundo donax) alter the natural 
hydrology of stream drainages by eliminating sandbars, breeding pools, 
and upland habitats. Tamarisk is an aggressive, woody invasive plant 
species that can tolerate a variety of environmental conditions and has 
become established over as much as a million acres of floodplains, 
riparian areas, wetlands, and lake margins in the western United States 
(Carpenter 2004, pp. 1-30). Tamarisk can replace or displace native 
woody species such as cottonwood and willow which occupy similar 
habitats, especially when timing and amount of peak water discharge, 
salinity, temperature, and substrate texture have been altered by human 
activities (Carpenter 2004, pp. 1-30). Tamarisk also consumes large 
quantities of water, possibly more than woody native plant species 
occupying the same habitat (Carpenter 2004, p. 3). Highly resistant to 
removal by flooding, tamarisk has the potential to form dense corridors 
along most large streams. Where this has been allowed to occur, 
tamarisk has replaced native vegetation, invaded sand bars, and led to 
channelization by constricting flood flows. Arundo donax is a tall, 
grass-like plant that grows up to 20 ft (6.1 m) in height with jointed 
stems that resemble corn stalks. Arundo donax also invades stream banks 
and lakeshores, where it can completely displace native vegetation, 
reduce wildlife habitat, increase fire risks, and alter flow regimes 
which can cause flooding (Ventura County 2006, pp. 21-23).
    In summary, predation from introduced aquatic species and the loss 
of habitat, coupled with habitat modifications due to the establishment 
of nonnative plants and the manipulation of water levels in many 
central and southern California streams and rivers, have caused arroyo 
toads to disappear from a large portion of their previously occupied 
habitat in California.

Previous Federal Action

    For more information on previous Federal actions concerning the 
arroyo toad, refer to our final designation of critical habitat 
published in the Federal Register on April 13, 2005 (70 FR 19562). On 
July 20, 2007 (Service 2007, pp. 1-2), we announced that we would 
review the April 13, 2005, final rule after questions were raised about 
the integrity of scientific information used and whether the decision 
made was consistent with the appropriate legal standards. Based on our 
review of the previous final critical habitat designation, we 
determined it was necessary to revise critical habitat and this rule 
proposes those revisions. On December 19, 2007, the Center for 
Biological Diversity filed a complaint in the U.S. District Court for 
the Southern District of California challenging our designation of 
critical habitat for the arroyo toad (Center for Biological Diversity 
v. U.S. Fish and Wildlife Service, Case No. 07-2380-JM-AJB). On June 5, 
2008, the court entered a consent decree requiring a proposed revised 
critical habitat rule to be submitted to the Federal Register by 
October 1, 2009, and a final revised critical habitat designation to be 
submitted to the Federal Register by October 1, 2010.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by a 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features;
    (a) Essential to the conservation of the species; and
    (b) That may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by a 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Conservation, as defined under section 3 of the Act, means the use 
of all methods and procedures that are necessary to bring any 
endangered species or threatened species to the point at which the 
measures provided under the Act are no longer necessary. Such methods 
and procedures include, but are not limited to, all activities 
associated with scientific resources management such as research, 
census, law enforcement, habitat acquisition and maintenance, 
propagation, live trapping and transplantation, and in the 
extraordinary case where population

[[Page 52617]]

pressures within a given ecosystem cannot otherwise be relieved, may 
include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against Federal agencies carrying out, funding, 
or authorizing activities that are likely to result in the destruction 
or adverse modification of critical habitat. Section 7(a)(2) of the Act 
requires consultation on Federal actions that may affect critical 
habitat. The designation of critical habitat does not affect land 
ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow the government 
or public to access private lands. Such designation does not require 
implementation of restoration, recovery, or enhancement measures by 
private landowners. Where a landowner seeks or requests Federal agency 
funding or authorization of an activity that may affect a listed 
species or critical habitat, the consultation requirements of section 
7(a)(2) would apply, but even in the event of a destruction or adverse 
modification finding, the Federal action agency's and the applicant's 
obligation is not to restore or recover the species, but to implement 
reasonable and prudent alternatives to avoid destruction or adverse 
modification of critical habitat.
    To be considered for inclusion in a critical habitat designation, 
habitat within the geographical area occupied by the species at the 
time it was listed must contain the physical or biological features 
that are essential to the conservation of the species. Areas supporting 
the essential physical or biological features are identified, to the 
extent known using the best scientific data available, as the habitat 
areas that provide essential life cycle needs of the species; that is, 
areas on which are found the primary constituent elements laid out in 
the appropriate quantity and spatial arrangement essential to the 
conservation of the species. Habitat within the geographical area 
occupied by the species at the time of listing that contains features 
essential to the conservation of the species meets the definition of 
critical habitat only if these features may require special management 
considerations or protection. Under the Act and the regulations at 50 
CFR 424.12, we can designate critical habitat in areas outside the 
geographical area occupied by the species at the time it is listed only 
when we determine that the best available scientific data demonstrate 
that the designation of those areas is essential for the conservation 
of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards Under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality 
Guidelines, provide criteria, establish procedures, and provide 
guidance to ensure that our decisions are based on the best scientific 
data available. They require our biologists, to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat.
    When we are determining which areas to propose as revised critical 
habitat, our primary source of information is generally the information 
developed during the listing process for the species and any previous 
designations of critical habitat. Additional information sources may 
include the recovery plan and 5-year reviews for the species, articles 
in peer-reviewed journals, conservation plans developed by States and 
counties, scientific status surveys and studies, biological 
assessments, or other unpublished materials and expert opinion or 
personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. In particular, we recognize that climate change may cause 
changes in the arrangement of occupied habitat patches. Current climate 
change predictions for terrestrial areas in the Northern Hemisphere 
indicate warmer air temperatures, more intense precipitation events, 
and increased summer continental drying (Field et al. 1999, pp. 1-3; 
Hayhoe et al. 2004, p. 12422; Cayan et al. 2005, p. 6; 
Intergovernmental Panel on Climate Change 2007, p. 11; Cayan et al. 
2009, p. xi). However, predictions of climatic conditions for smaller 
sub-regions such as California remain uncertain. It is unknown at this 
time if climate change in California will result in a warmer trend with 
localized drying, higher precipitation events, or other effects. Thus, 
the information currently available on the effects of global climate 
change and increasing temperatures does not make sufficiently precise 
estimates of the location and magnitude of the effects. Nor are we 
currently aware of any climate change information specific to the 
habitat of the arroyo toad that would indicate what areas may become 
important to the species in the future. Therefore, we are unable to 
determine what additional areas, if any, may be appropriate to include 
in the proposed revised critical habitat for this species; however, we 
specifically request information from the public on the currently 
predicted effects of climate change on the arroyo toad and its habitat. 
Additionally, we recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated critical habitat area is unimportant or 
may not be required for recovery of the species.
    Areas that support populations of the arroyo toad, but are outside 
the critical habitat designation, may continue to be subject to 
conservation actions we and other Federal agencies implement under 
section 7(a)(1) of the Act. They are also subject to the regulatory 
protections afforded by the section 7(a)(2) jeopardy standard, as 
determined on the basis of the best available information at the time 
of the agency action. Federally funded or permitted projects affecting 
listed species outside their designated critical habitat areas may 
still result in jeopardy findings in some cases. Similarly, critical 
habitat designations made on the basis of the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans 
(HCPs), section 7 consultations, or other species conservation planning 
efforts if new information available to these planning efforts calls 
for a different outcome.

Methods

    As required by section 4(b) of the Act, we used the best scientific 
and commercial data available in determining which areas within the 
geographic area occupied by the species at the time of listing contain 
the features essential to the conservation of the arroyo toad, and 
which areas outside the geographical area occupied at the time of 
listing are essential for the conservation of the species. We reviewed 
information used to prepare the 2004 proposed critical habitat rule (69 
FR 23254); the approach to provide conservation for the arroyo toad 
provided in its recovery plan (Service 1999, pp. 1-119); the 5-year 
review for the arroyo toad (Service 2009, pp. 1-51); the California 
Department of Fish and Game's (CDFG) California Natural Diversity 
Database (CNDDB) records; published peer-reviewed articles;

[[Page 52618]]

unpublished papers and reports; academic theses; survey results; 
Geographic Information System (GIS) data (such as species occurrences, 
soil data, land use, topography, and ownership maps); and 
correspondence to the Service from recognized experts. We solicited new 
information collected since publication of the recovery plan and 2005 
final critical habitat designation, including information from State, 
Federal, and Tribal governments, and from academia and private 
organizations that have collected scientific data on the arroyo toad. 
We also based our determination of areas meeting the definition of 
critical habitat for the arroyo toad in part on the approach in the 
recovery plan that focuses on protection and management of breeding and 
non-breeding habitat on a watershed basis for the conservation of the 
species (Service 1999, pp. 1-119).

Physical and Biological Features

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12(b), in determining which areas within the geographical 
area occupied at the time of listing to propose as revised critical 
habitat, we consider the physical and biological features that are 
essential to the conservation of the species that may require special 
management considerations or protection. Those features are the primary 
constituent elements (PCEs) laid out in the appropriate quantity and 
spatial arrangement for conservation of the species. The PCEs include, 
but are not limited to:
    (1) Space for individual and population growth, and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, and rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical, and ecological 
distributions of a species.
    We derive the specific PCEs required for conservation of the arroyo 
toad from its biological needs. The areas proposed for designation as 
revised critical habitat provide aquatic habitat for breeding 
activities and upland habitat for shelter, foraging, predator 
avoidance, and dispersal across the arroyo toad's current range. The 
PCEs and the resulting physical and biological features essential to 
the conservation of the species are determined based on studies of 
arroyo toad ecology as described in the ``Background'' section of this 
proposed rule and in the final listing rule published in the Federal 
Register on December 16, 1994 (59 FR 64859).

Space for Individual and Population Growth, and for Normal Behavior

    The arroyo toad is found along medium-to-large streams in coastal 
and desert drainages in central and southern California, and Baja 
California, Mexico. It occupies aquatic, riparian, and upland habitats 
in a number of the remaining suitable drainages within its range. 
Suitable habitat for the arroyo toad is created and maintained by the 
fluctuating hydrological, geological, and ecological processes that 
naturally occur in riparian ecosystems and adjacent uplands (Campbell 
et al. 1996, pp. 13-15; Service 1999, p. 39). Periodic flooding that 
modifies stream channels, redistributes channel sediments, and alters 
pool location and form, coupled with upper terrace stabilization by 
vegetation, is required to keep a stream segment suitable for all life 
stages of the arroyo toad (Campbell et al. 1996, p. 13; Service 1999, 
p. 39). This natural flooding regime helps maintain areas of open, 
sparsely vegetated, sandy stream channels and terraces.
    The substrate in habitats preferred by arroyo toads consists 
primarily of sand, fine gravel, or pliable soil, with varying amounts 
of large gravel, cobble, and boulders. Areas that are damp and have 
less than 10 percent vegetation cover provide the best conditions for 
juvenile survival and rapid growth (Campbell et al. 1996, p. 12; 
Service 1999, pp. 32-34). Arroyo toads breed in the quiet margins of 
open streams and avoid sites with deep or swift water, tree canopy 
cover, or steeply incised banks. Larvae occupy shallow areas of open 
streambeds on substrates ranging from silt to cobble, with preferences 
for sand or gravel. Newly metamorphosed arroyo toads and juveniles 
remain on sparsely vegetated sand and gravel bars bordering the natal 
pool for 3 to 5 weeks (Sweet 1992, p. 52).
    Arroyo toads must be able to move between the stream and upland 
foraging sites, as well as up and down the stream corridor. Juveniles 
and adult arroyo toads require and spend much of their lives in 
riparian and upland habitats adjacent to breeding locations (Campbell 
et al. 1996, p. 12). Riparian habitats used for foraging and burrowing 
include sand bars, alluvial terraces, and streamside benches that lack 
vegetation, or are sparsely to moderately vegetated. Upland habitats 
used by arroyo toads during both the breeding and non-breeding seasons 
include alluvial scrub, coastal sage scrub, chaparral, grassland, and 
oak woodland.

Food, Water, and Physiological Requirements

    Arroyo toad tadpoles eat microscopic algae, bacteria, and 
protozoans consumed from the spaces among pebbles, gravel, and sand, or 
abraded from stones (Sweet 1992, p. 82). Juveniles and adults eat 
insects, although ants are preferred. When foraging, arroyo toads are 
often found around the drip lines of oak trees. These areas often lack 
vegetation, yet have levels of prey that will support arroyo toads. 
When active at night, toads often are observed near ant trails feeding 
on ants, beetles, and other prey.

Cover or Shelter

    During the day and other periods of inactivity, arroyo toads seek 
shelter by burrowing into sand. Thus, areas of sandy or friable 
(readily crumbled) soils are necessary, but these soils can be 
interspersed with gravel or cobble deposits. Additionally, arroyo toads 
may seek temporary shelter under rocks or debris and have been found in 
mammal burrows on occasion. Upland sites with compact soils can also be 
used for foraging and dispersal (Holland 2000, in litt.).

Sites for Breeding, Reproduction, and Rearing of Offspring

    The arroyo toad has specialized breeding habitat requirements. They 
favor shallow pools (less than 12 in (30 cm) deep) and open sand and 
gravel channels along low-gradient (typically less than 6 percent) 
reaches of medium to large streams (Service 1999, pp. 31-32). These 
streams can have either intermittent or perennial streamflow and 
typically experience periodic flooding that scours vegetation and 
replenishes fine sediments. In at least some portions of its range, the 
species also breeds in smaller streams and canyons where low-gradient 
breeding sites are more sporadically distributed. Breeding pools must 
persist long enough for the completion of larval development, which is 
generally March through June, depending on location and weather. 
Because the suitability of breeding pools may vary from year to year 
due to the dynamics of southern California riparian systems and flood 
regimes, adult arroyo toads may move up or down stream in search of 
suitable breeding pools, or not breed that year (Campbell et al. 1996, 
p. 14).
    Arroyo toads breed in rivers with intermittent, seasonal flow, with 
a breeding period that may range from late February through July. 
Breeding at

[[Page 52619]]

a given site may extend over several months (Griffin and Case 2001, p. 
634). Breeding arroyo toads lay their eggs in water over substrates of 
sand, gravel, or cobble in open sites such as overflow pools, old flood 
channels, and shallow pools along streams. Such habitats rarely have 
closed canopies over the lower banks of the stream channel due to 
periodic flood events. Heavily shaded pools are generally unsuitable 
for larval and juvenile arroyo toads because of lower water and soil 
temperatures and poor algal mat development. Pools less than 12 in (30 
cm) deep with clear water, flow rates less than 0.2 ft per second (5 cm 
per second), and bottoms composed of sand or well-sorted fine gravel 
are favored by adults for breeding and egg deposition (Sweet 1992, pp. 
29-37). Although egg strings are laid in very slow-moving water, larvae 
(tadpoles) can be found in water velocities of up to 1.0 to 1.3 ft per 
second (30 to 40 cm per second) (Sweet 1992, p. 29). Breeding may occur 
on several dates at a single site, and eggs may be deposited over a 
period of 7 to 8 weeks (Campbell et al. 1996, p. 6). Breeding pools 
must persist a minimum of 2 months for the completion of larval 
development because changes in stream level or altering of the stream 
bed or breeding pool may cause high mortality to eggs and small larvae, 
sweeping them downstream, stranding and exposing them to desiccation, 
or burying and asphyxiating them with silt (Campbell et al. 1996, p. 
6). Larvae usually hatch in 4 to 6 days at water temperatures of 54 to 
59 degrees Fahrenheit (12 to 16 degrees Celsius). Tadpoles disperse 
from the pool margin into the surrounding shallow water, where they 
spend an average of 10 weeks. After metamorphosis, the juvenile arroyo 
toads remain on the bordering gravel bars until the pool dries out 
(usually from 8 to 12 weeks depending on the site and rainfall).

Primary Constituent Elements (PCEs) for the Arroyo Toad

    Pursuant to the Act and its implementing regulations, when 
considering the designation of critical habitat, we must focus on the 
known principal primary constituent elements within the geographical 
area occupied by the arroyo toad at the time of listing that are 
essential to the conservation of the species. The essential physical 
and biological features are those PCEs laid out in an appropriate 
quantity and spatial arrangement determined to be essential to the 
conservation of the species. All areas proposed in this rule as revised 
critical habitat for the arroyo toad are currently occupied, are within 
the geographical area occupied by the species at the time of listing, 
and contain sufficient PCEs to support at least one life-history 
function.
    Based on the above needs and our current knowledge of the life 
history, biology, and ecology of the species, and the habitat 
requirements for sustaining the essential life-history functions of the 
species, we have determined that the PCEs specific to the arroyo toad 
are:
    (1) Rivers or streams with hydrologic regimes that supply water to 
provide space, food, and cover needed to sustain eggs, tadpoles, 
metamorphosing juveniles, and adult breeding toads. Breeding pools must 
persist a minimum of 2 months for the completion of larval development. 
However, due to the dynamic nature of southern California riparian 
systems and flood regimes, the location of suitable breeding pools may 
vary from year to year. Specifically, the conditions necessary to allow 
for successful reproduction of arroyo toads are:
     Breeding pools with areas less than 12 in (30 cm) deep;
     Areas of flowing water with current velocities less than 
1.3 ft per second (40 cm per second); and
     Surface water that lasts for a minimum of 2 months during 
the breeding season (a sufficient wet period in the spring months to 
allow arroyo toad larvae to hatch, mature, and metamorphose).
    (2) Riparian and adjacent upland habitats, particularly low-
gradient (typically less than 6 percent) stream segments and alluvial 
streamside terraces with sandy or fine gravel substrates that support 
the formation of shallow pools and sparsely vegetated sand and gravel 
bars for breeding and rearing of tadpoles and juveniles; and adjacent 
valley bottomlands that include areas of loose soil where toads can 
burrow underground, to provide foraging and living areas for juvenile 
and adult arroyo toads.
    (3) A natural flooding regime, or one sufficiently corresponding to 
natural, characterized by intermittent or near perennial flow that 
contributes to the persistence of shallow pools into at least mid-
summer, and that maintains areas of open, sparsely vegetated, sandy 
stream channels and terraces by periodically scouring riparian 
vegetation; and also that modifies stream channels and terraces and 
redistributes sand and sediment, such that breeding pools and terrace 
habitats with scattered vegetation are maintained.
    (4) Stream channels and adjacent upland habitats that allow for 
movement to breeding pools, foraging areas, overwintering sites, 
upstream and downstream dispersal, and connectivity to areas that 
contain suitable habitat.
    In summary, the need for space for individual and population growth 
and normal behavior is met by PCE (1); the need for food, water and 
physiological requirements is met by PCE (1); cover and shelter 
requirements are met by PCE (2); areas for breeding reproduction, and 
rearing of offspring are met by PCEs (1), (2), and (3); and habitats 
representative of the historical, geographical, and ecological 
distributions of a species are met by PCE (4).
    With this proposed revised designation of critical habitat, we 
intend to conserve the physical and biological features that are 
essential to the conservation of the species, through the 
identification of the appropriate quantity and spatial arrangement of 
the PCEs sufficient to support the life-history functions of the 
species. Because not all life-history functions require all the PCEs, 
not all areas designated as critical habitat will contain all the PCEs. 
Each of the areas proposed for designation in this rule has been 
determined to contain sufficient PCEs to provide for one or more of the 
life-history functions of the arroyo toad.

Special Management Considerations or Protection

    In accordance with the definition of critical habitat in section 
3(5)(A) of the Act, when designating critical habitat within the 
geographical area occupied by the species at the time of listing, we 
assess whether the physical and biological features essential to the 
conservation of the arroyo toad may require special management 
considerations or protection. All areas being proposed as critical 
habitat may require some level of management to address current and 
future threats to the arroyo toad, to maintain or enhance the physical 
and biological features essential to its conservation, and to ensure 
the recovery and survival of the species.
    A detailed discussion of threats impacting the physical and 
biological features essential to the conservation of the arroyo toad 
which may require special management considerations or protection, can 
be found in the final listing rule (59 FR 64859; December 16, 1994), 
the 2001 critical habitat designation (66 FR 9414; February 7, 2001), 
the 2005 critical habitat designation (70 FR 19561; April 13, 2005), 
and the recovery plan (Service 1999, pp. 1-119). In summary, these 
threats include habitat destruction and alteration due to short- and 
long-term changes in river hydrology, including

[[Page 52620]]

construction of dams and water diversions; alteration of riparian 
wetland habitats by agriculture and urbanization; construction of 
roads; site-specific damage by off-highway vehicle use and other 
recreational activities; overgrazing; and mining activities. Arroyo 
toads and their habitats are also threatened by introduced nonnative 
predators (such as bullfrogs and predatory fish), drought, periodic 
fires, unseasonal water releases from dams, livestock grazing, and 
light and noise pollution from adjacent developments and campgrounds. 
Activities that may require special management considerations or 
protection of the features essential to the conservation of the arroyo 
toad include, but are not limited to: dam construction and operation, 
river diversion, conversion of riparian wetland habitat by agriculture 
and urbanization, road construction, off-highway vehicle use, 
campground development, grazing, and mining. In each proposed critical 
habitat unit, special management may be needed to ensure that aquatic 
and terrestrial habitat are able to provide abundant breeding and non-
breeding habitat, prey habitat, shelter, and connectivity within the 
landscape.
    In summary, we find that each of the areas we are proposing as 
revised critical habitat contains features essential to the 
conservation of the arroyo toad, and that these features may require 
special management considerations or protection. Special management 
considerations or protection may be required to eliminate, or reduce to 
negligible level, the threats affecting each unit and to preserve and 
maintain the essential features that the proposed critical habitat 
units provide to the arroyo toad. A more comprehensive discussion of 
threats facing individual sites is in the individual unit descriptions.
    The designation of critical habitat does not imply that lands 
outside of critical habitat do not play an important role in the 
conservation of the arroyo toad. Activities with a Federal nexus that 
may affect those unprotected areas outside of critical habitat, such as 
development, agricultural activities, and road construction, are still 
subject to review under section 7 of the Act if they may affect the 
arroyo toad. The take prohibitions of section 9 of the Act also 
continue to apply both inside and outside of designated critical 
habitat. Take is broadly defined in the Act as to harass, harm, pursue, 
hunt, shoot, wound, kill, trap, capture, or collect a listed species, 
or to attempt to engage in any such conduct.

Criteria Used To Identify Critical Habitat

    Using the best scientific and commercial data available as required 
by section 4(b)(1)(A) of the Act, we identified those areas to propose 
for revised designation as critical habitat that, within the 
geographical area occupied by the species at the time of listing (see 
``Geographic Range'' section), possess those physical and biological 
features essential to the conservation of the arroyo toad and which may 
require special management considerations or protection. We also 
considered the area outside the geographical area occupied by the 
species at the time of listing for any areas that are essential for the 
conservation of the arroyo toad. The material we used included the 1994 
final listing rule (59 FR 64859), the 2004 proposed critical habitat 
rule (69 FR 23254), 2008 CNDDB records, the arroyo toad recovery plan, 
data in reports submitted during section 7 consultations and by 
biologists holding section 10(a)(1)(A) recovery permits, research 
published in peer-reviewed articles and presented in academic theses 
and agency reports, the 5-year review for the arroyo toad (Service 
2009, pp. 1-51), and regional GIS coverages. We analyzed this 
information to develop criteria for identifying areas that contain the 
PCEs in the appropriate quantit