Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Salt Creek Tiger Beetle, 17466-17509 [2010-7121]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 75, Number 65 (Tuesday, April 6, 2010)]
[Rules and Regulations]
[Pages 17466-17509]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-7121]



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Part II





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; Designation of Critical 
Habitat for the Salt Creek Tiger Beetle; Final Rule

Federal Register / Vol. 75, No. 65 / Tuesday, April 6, 2010 / Rules 
and Regulations

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2007-0014]
[MO 92210-0-0009]
RIN 1018-AT79


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for the Salt Creek Tiger Beetle

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service/USFWS), 
designate critical habitat for the Salt Creek tiger beetle (Cicindela 
nevadica lincolniana) under the Endangered Species Act of 1973, as 
amended (Act). In total, approximately 1,933 acres (ac) (782 hectares 
(ha)) located in Lancaster and Saunders Counties, Nebraska, fall within 
the boundaries of the critical habitat designation.

DATES: This rule becomes effective on May 6, 2010.

ADDRESSES: The final rule, final economic analysis, and map of critical 
habitat are available on the Internet at https://www.regulations.govand 
https://www.fws.gov/mountain-prairie/species/invertebrates/saltcreektiger/index.htm. Supporting documentation we used in preparing 
this final rule are available for public inspection, by appointment, 
during normal business hours, at the U.S. Fish and Wildlife Service, 
Nebraska Ecological Services Field Office, 203 West Second Street, 
Federal Building, 2\nd\ Floor, Grand Island, NE 68801; telephone 308-
382-6468; facsimile 308-384-6468.

FOR FURTHER INFORMATION CONTACT: John Cochnar, Acting Field Supervisor, 
U.S. Fish and Wildlife Service, Nebraska Ecological Services Field 
Office, telephone 308-382-6468 (see ADDRESSES section). If you use a 
telecommunications device for the deaf (TDD), call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    It is our intent to discuss only those topics directly relevant to 
the development and designation of critical habitat for the Salt Creek 
tiger beetle in this final rule. For more information on the biology 
and ecology of the Salt Creek tiger beetle, refer to the final rule 
listing the subspecies as endangered that published in the Federal 
Register on October 6, 2005 (70 FR 58335), proposed critical habitat 
rule published in the Federal Register on December 12, 2007 (72 FR 
70716), and revised proposed rule published in the Federal Register on 
April 28, 2009 (74 FR 19167).

Subspecies Information

    The Salt Creek tiger beetle is an active, ground-dwelling, 
predatory insect endemic to saline wetlands and streams in the eastern 
saline wetlands of Lancaster and Saunders Counties, Nebraska. Saline 
wetlands occur in swales and depressions, and at one time represented 
approximately 65,065 acres (ac) (26,342 hectares (ha)) within the 
floodplain of Salt Creek and its tributaries (Gilbert and Stutheit 
1994, p. 5). Saline wetlands are characterized by saline soils and 
halophytes (plants adapted to saline conditions) and are often 
associated with a saline stream within the Salt Creek basin (LaGrange 
1997, p. 19). Saline wetlands usually have a central area that is 
devoid of vegetation and, when dry, exhibit salt-encrusted mudflats 
(barren salt flats) (LaGrange 1997, p. 19).
    Channel-straightening projects in the early 1900s (Rus et al. 2003, 
p. 2), and residential, commercial, industrial, infrastructure, and 
agricultural developments resulted in degradation, loss, and 
fragmentation of saline wetland and stream habitats. These 
modifications have had a negative impact on the Salt Creek tiger 
beetle, an insect adapted to saline wetland and stream ecosystems 
(Ratcliffe and Spomer 2002, p. 5).
    As recently as 1994, six populations of Salt Creek tiger beetles 
were distributed along Oak, Little Salt, and Rock Creeks (Spomer et al. 
1999, p. 1). Since 1994, half of these populations have been extirpated 
and the remaining three extant populations are all located along a 
single waterway: Little Salt Creek (Spomer et al. 2004, p. 2). The two 
largest populations along Little Salt Creek exist within 1 mile (mi) 
(1.61 kilometer (km)) of each other in an area on the north side of 
Lincoln, Nebraska, where extensive urban growth and development has 
already occurred and continues. The proximity of these remaining 
populations to one another greatly increases the threat of subspecies' 
extinction because a single stochastic event could cause the loss of 
these remaining habitats or populations. In 2004, the number of adult 
Salt Creek tiger beetles declined by 25 percent from 2003 (Spomer et 
al. 2004, pp.1-2). In 2005, only 153 adult Salt Creek tiger beetles 
were found, a 73 percent decline from 2004, and the lowest count in the 
past 12 years of surveys (Spomer 2005, pers. comm.). In 2006, 466 Salt 
Creek tiger beetles were found, representing a 300 percent increase and 
demonstrating the dynamic nature of annual insect populations (Spomer 
2006, pers. comm.). However, in 2007, the population number had 
declined by approximately half, to 263 adults (Spomer 2007, pers. 
comm.). In 2008, 165 adult Salt Creek tiger beetles were detected 
during surveys (Spomer 2008, pers. comm.).

Previous Federal Actions

    The final rule to list the Salt Creek tiger beetle as endangered 
was published in the Federal Register on October 6, 2005 (70 FR 58335). 
We stated that critical habitat was prudent and determinable, however, 
we did not designate critical habitat at the time of listing because we 
were in the process of identifying the physical and biological features 
essential to the conservation of the Salt Creek tiger beetle. We 
published a proposed rule to designate critical habitat in the Federal 
Register on December 12, 2007 (72 FR 70716). On June 3, 2008, we 
published a notice in the Federal Register to reopen the comment period 
and announce a public hearing (73 FR 31665). On April 28, 2009, we 
published a revised proposed rule in the Federal Register to include an 
additional 138 ac (56 ha) as critical habitat and reopened the public 
comment period (74 FR 19167). We have not yet developed a recovery plan 
for the Salt Creek tiger beetle.

Summary of Comments and Recommendations

    We requested written comments from the public and contacted 
appropriate Federal, State, and local agencies; scientific 
organizations; and other interested parties and invited them to comment 
on the proposed rule, draft environmental assessment, and draft 
economic analysis (Draft EA) during three comment periods. The first 
comment period opened on December 12, 2007, the date of publication of 
the proposed rule (72 FR 70716), and closed on February 11, 2008. We 
received two requests for a public hearing during this comment period. 
On June 3, 2008, we reopened the comment period until July 11, 2008, 
and announced that a public open house and hearing would be held on 
July 1, 2008, in Lincoln, Nebraska (73 FR 31665). On April 28, 2009, we 
reopened the comment period until May 28, 2009, and announced our 
proposal to include an additional 138 ac (56 ha) as critical habitat 
for the Salt Creek tiger

[[Page 17467]]

beetle along Little Salt Creek in Units 1, 2, and 3 (74 FR 19167).
    During the first comment period, we received six comment letters 
directly addressing the proposed critical habitat designation: two from 
peer reviewers, one from a local government agency, two from private 
organizations, and one from an individual. During the second comment 
period, we received seven comment letters directly addressing the 
proposed critical habitat designation: one from a State agency, one 
from a peer reviewer, one from a private business, two from private 
organizations, and two from individuals. We also accepted comments from 
three peer reviewers between the two comment periods. During the public 
hearing, five speakers presented their comments relative to the 
proposed rule to designate critical habitat. During the third comment 
period, we received one comment letter directly addressing our proposal 
to include an additional 138 ac (56 ha).
    We reviewed all comments we received during all three comment 
periods and at the public hearing for substantive issues and new 
information regarding the designation of critical habitat for the Salt 
Creek tiger beetle. We address these comments in the following summary, 
and have incorporated them into the final rule as appropriate.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we solicited expert opinions from 10 knowledgeable individuals 
with scientific and economic expertise with the subspecies, the 
geographic region in which the subspecies occurs, the economic 
analysis, and relative conservation biology principles. We received 
responses from 6 of the 10 peer reviewers.

Peer Reviewer Comments

    (1) Comment: One peer reviewer commented that we should include a 
segment of Little Salt Creek in the critical habitat designation 
because it contains the largest known population of the Salt Creek 
tiger beetle.
    Our Response: We agree that we should include that segment of 
Little Salt Creek in the designation, and we have included an 
additional 138 ac (56 ha) of critical habitat (74 FR 19167) that 
includes that segment. In recognition of the importance of saline seeps 
to the Salt Creek tiger beetle, we have included currently occupied 
segments of Little Salt Creek within the critical habitat units. We 
solicited comments from the public on the addition of these areas in 
the Federal Register (74 FR 19167).
    (2) Comment: One peer reviewer commented that the proposed rule 
contained no discussion of the role of groundwater in supplying the 
needed salinity to wetlands which sustain the Salt Creek tiger beetle, 
nor does the proposed rule use groundwater discharge locations or 
regional flow conditions to designate critical habitat areas. The peer 
reviewer also recommended making reference in the proposed rule to the 
saline recharge area and its influence on saline habitats used by the 
Salt Creek tiger beetle. The peer reviewer also suggested the inclusion 
of buffer areas encompassing saline wetlands or implementation of 
restrictions to limit the amount of freshwater intrusion in saline 
wetland habitats.
    Our Response: We agree with the peer reviewer about the importance 
of discussing and considering groundwater, salinity, and saline 
recharge areas and their involvement in maintaining habitat for this 
subspecies. However, groundwater that supplies the needed salinity to 
saline wetland habitats, groundwater discharge locations, and regional 
flow conditions were not used to identify critical habitat areas, 
because this information is currently not available at the resolution 
required to identify critical habitat boundaries. We will continue to 
carefully consider the influence of groundwater discharge during the 
development of a recovery plan for the Salt Creek tiger beetle.
    We also concur with the peer reviewer's comment that buffers 
provide an important function to prevent excess freshwater and sediment 
intrusion into saline wetland habitats. Freshwater intrusion is a 
threat to the habitat; however, a critical habitat designation is not 
the proper forum for implementing restrictions to prevent freshwater 
and sediment intrusion that result from impacts outside of the critical 
habitat boundaries. Site-specific recommendations to address freshwater 
and sediment intrusion can be developed when the Service reviews 
proposed Federal actions that may impact saline wetlands and streams 
within the critical habitat areas. For example, Federal actions that 
are proposed to occur outside of the boundaries of critical habitat, 
but could still result in the destruction or adverse modification of 
critical habitat, would be considered a component of the effects 
analysis when the Service conducts a review of a proposed Federal 
action.
    (3) Comment: One peer reviewer indicated that he and other 
biologists familiar with the Salt Creek tiger beetle believed that 
15,000 ac (6,070 ha) should be included in the critical habitat 
designation based on site inspections, geographic information system 
analyses, soil maps, and an evaluation of the presence of the primary 
constituent elements at each of these sites. However, the peer reviewer 
said that we proposed only 1,742 ac (705 ha) as critical habitat in the 
proposed rule. Five public commenters also stated that the proposed 
rule falls short of that which is essential for the conservation of the 
Salt Creek tiger beetle. A peer reviewer questioned our scientific 
rationale for the decrease in acreage and further pointed out that 
having multiple critical habitat units in multiple stream systems 
reduces the risk of extinction.
    Our Response: An evaluation completed by a team of biologists 
identified approximately 15,000 ac (6,070 ha) of habitat that could 
potentially be critical habitat for the Salt Creek tiger beetle. 
Critical habitat is defined in section 3(5)(A) 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 that are essential to the 
conservation of the species and which 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. We are designating all the areas occupied by the 
subspecies at the time of listing because we determined that they 
contain the physical and biological features essential to the 
conservation of the subspecies, and that they require special 
management considerations and protection. In delineating critical 
habitat we focused on: (1) Areas known to be occupied that contain the 
primary constituent elements in the appropriate quantity and spatial 
arrangement that form the features essential for the conservation of 
the tiger beetle; or (2) unoccupied areas that are essential to 
conservation of the Salt Creek tiger beetle.
    We determined that most of the 15,000 ac (6,070) do not presently 
have the ability to support sustainable populations of beetles. For 
example, we eliminated the Oak Creek, Middle Creek/Haines Branch, 
Ashland, Upper Salt Creek, and Roca areas from further consideration 
because these areas contain degraded saline wetlands and

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stream segments, and are currently unable to support the Salt Creek 
tiger beetle. Further, with the exception of Oak Creek, we have no 
information that the Salt Creek tiger beetle ever inhabited these 
areas. We also eliminated palustrine (inland wetland lacking flowing 
water) freshwater wetlands and contiguous stream segments between 
populations from further consideration because these areas may not 
presently have the ability to support sustainable populations of 
beetles. Our evaluation conducted for the proposed rule resulted in the 
identification of 1,795 ac (727 ha) of habitat that are essential for 
the conservation of the Salt Creek tiger beetle. Subsequent to further 
evaluation and based upon the comments received, we now include an 
additional 138 ac (56 ha) of stream habitat along Little Salt Creek in 
Units 1, 2, and 3 to encompass occupied habitat, protect saline seeps, 
and ensure that a movement corridor is maintained for the beetle. This 
inclusion increases the area of critical habitat to 1,933 ac (782 ha).
    We agree that multiple areas should be considered to reduce the 
risk of extinction that could be conveyed to a single population of the 
Salt Creek tiger beetle. Ensuring the existence of a potential refugium 
in a different watershed than the three currently occupied units is 
essential to the conservation of the subspecies, should an event or 
series of events threaten the existence of the remaining three 
populations. Consequently, we have identified a currently unoccupied 
area on Rock Creek (associated with the Jack Sinn Wildlife Management 
Area of the Nebraska Game and Parks Commission (NGPC)) as an additional 
unit for final critical habitat designation. This area was known to be 
occupied as recently as 1998 (Spomer et al. 2001, p. 1) and contains 
all the features essential to the conservation of the subspecies. We do 
not include other saline wetlands in the critical habitat designation 
based on a determination that they are not essential to the 
conservation of the subspecies, because they do not contain the 
features essential to the conservation of the subspecies and do not 
support sustainable populations of the Salt Creek tiger beetle. 
However, with restoration efforts, these areas could be important for 
the recovery of the Salt Creek tiger beetle.
    (4) Comment: One peer reviewer recommended the inclusion of 
additional unoccupied areas as critical habitat to augment currently 
available habitat for the Salt Creek tiger beetle that is under heavy 
development pressure.
    Our Response: We have included an additional 138 ac (56 ha) of 
habitat along Little Salt Creek in Units 1, 2, and 3 in the critical 
habitat designation to increase the final designation from 1,795 to 
1,933 ac (727 to 782 ha). This additional acreage includes an area 
along Little Salt Creek currently occupied by the Salt Creek tiger 
beetle, and currently under heavy development pressure, and protects 
important saline seep and movement corridor habitats along Little Salt 
Creek for the subspecies. Regarding the inclusion of unoccupied 
habitat, see our response to Comment 3 above.

Public Comments

Comments related to the rationale for determining acreage of critical 
habitat
    (5) Comment: One commenter stated that we did not provide 
scientific rationale for how the proposed designation would allow for 
the recovery and long-term maintenance of the Salt Creek tiger beetle.
    Our Response: Designation of critical habitat in and of itself will 
likely not ensure the recovery and long-term maintenance of the Salt 
Creek tiger beetle. Designation of critical habitat; preparation and 
implementation of a recovery plan; and partnerships with private 
landowners; State, Federal, and local resource agencies; and city and 
county entities will support important long-term recovery goals. We 
believe the final critical habitat designation is adequate in size and 
distribution to provide for the conservation and recovery of the Salt 
Creek tiger beetle.
Comments related to inclusion of occupied habitat and movement 
corridors as critical habitat
    (6) Comment: Three commenters pointed out that we did not include 
all populations of the Salt Creek tiger beetle in the proposed rule, 
and that proposed critical habitat areas along Little Salt Creek are 
too fragmented and do not provide corridors for movement of the Salt 
Creek tiger beetle. Three commenters stated that the proposed rule 
acreage is inadequate in distribution to provide for the protection of 
extant populations and recovery of the subspecies.
    Our Response: Information we received during the public comment 
period identified that habitats occupied by the Salt Creek tiger beetle 
were not included in our proposed critical habitat designation. 
Consequently, as discussed in our response to Comment 1, we have added 
another 138 ac (56 ha) to the final critical habitat designation. In 
regard to the commenter's assertion about fragmentation, this 
additional area includes an area currently occupied by the Salt Creek 
tiger beetle that contains important saline seep and movement corridor 
habitats along Little Salt Creek (Units 1, 2, and 3). Furthermore, the 
critical habitat designation includes an unoccupied area along Rock 
Creek (Unit 4) that includes saline seep and movement corridor 
habitats. We believe that the final critical habitat designation is 
sufficient in size and distribution to provide for the conservation and 
recovery of the Salt Creek tiger beetle. We do not include other saline 
wetlands in the area in the critical habitat designation due to their 
inability to provide the PCEs in the appropriate quantity and spatial 
arrangement that form the features essential to the conservation of the 
subspecies, and to support a sustainable population of the Salt Creek 
tiger beetle.
    (7) Comment: One commenter stated that saline wetlands are 
dependent on a highly saline source of groundwater that mixes with 
surface water to create saline wetland complexes. The protection of 
critical habitat must consider those factors outside of the immediate 
saline habitat that impact the entire saline wetland.
    Our Response: Although groundwater is always recognized as an 
important factor in the ecology of saline wetlands and streams, little 
research is currently available to ascertain the influence of 
groundwater on the saline and stream system. However, we will carefully 
consider the influence of groundwater during the development of a 
recovery plan for the Salt Creek tiger beetle. Federal actions that are 
proposed to occur outside of the boundaries of critical habitat, but 
could still adversely affect critical habitat through groundwater 
impacts, can still be considered a component of the effects analysis 
when we conduct a review of a proposed Federal action to determine 
whether the proposed action would destroy or adversely modify critical 
habitat.
    (8) Comment: One commenter stated that maps showing critical 
habitat are unclear and acreage stated in the proposed rule is 
inconsistent with that stated in the press release.
    Our Response: The maps shown in the proposed rule lacked readily 
identifiable landmarks making identification of critical habitat 
difficult. In response to this, we prepared maps showing individual 
property parcels and the proposed critical habitat boundaries and made 
several sets of these maps available for public review at the public 
open house and hearing. The area in the proposed rule 1,795 ac

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(727 ha) is correct, whereas the area reported in the press release was 
in error. In recognition of this, we provided the correct acreage 
during media interviews and during a presentation and informal 
discussions at the public open house and hearing on July 1, 2008, in 
Lincoln, Nebraska. This final rule contains the correct area for the 
designation.
    (9) Comment: A commenter suggested we recognize that local 
government agencies, including the City of Lincoln and the Lower Platte 
South Natural Resource District, as part of the Saline Wetland 
Conservation Partnership, own or control 221 ac (89 ha) of proposed 
critical habitat.
    Our Response: We appreciate the suggestion and have made the 
appropriate addition to Table 1 of this rule.
    (10) Comment: One commenter inquired if other areas in Kansas and 
Oklahoma were available where the Salt Creek tiger beetle could be 
introduced.
    Our Response: The Salt Creek tiger beetle is endemic to the eastern 
saline wetland complex of Nebraska and survives under a narrow set of 
habitat characteristics that must include saline and stream habitats, 
appropriate hydrology, a prey base for adults and larvae, and movement 
corridors. We are considering possible future reintroductions of the 
Salt Creek tiger beetle at other saline wetlands in the eastern saline 
wetland complex of Nebraska. However, we are not considering other 
States because suitable habitat is not available and they are not known 
to be part of the historic range of the subspecies.
    (11) Comment: One commenter stated the proposed critical habitat 
does not provide the primary constituent elements (PCEs) needed to 
support existing populations.
    Our Response: In delineating critical habitat, we included areas 
either known to be occupied and containing the features essential to 
the conservation of the subspecies, or believed to be unoccupied but 
determined to be essential to conservation of the subspecies. The 
critical habitat designation provides the essential features identified 
as the PCEs in the appropriate quantity and spatial arrangement 
essential to the conservation of the subspecies. We discuss the PCEs 
for the Salt Creek tiger beetle in the ``Physical and Biological 
Features'' section below.
    (12) Comment: A commenter requested that we provide written 
assurances that their private business would not be affected by the 
critical habitat designation.
    Our Response: We cannot provide written assurances that the 
designation of critical habitat will not affect privately owned 
businesses because privately owned businesses can receive a Federal 
permit, funding, or authorization in the future. Critical habitat 
receives protection under section 7 of the Act through the prohibition 
against Federal agencies carrying out, funding, or authorizing 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. The designation of critical 
habitat does not allow the government or public to access private 
lands, nor does it require implementation of restoration, recovery, or 
enhancement measures by private landowners.
Comments related to the economic analysis (EA)
    (13) Comment: One peer reviewer stated that the estimated economic 
impacts of the critical habitat designation are unrealistically high 
given the lack of actual land sale transaction data used in the 
evaluation and failure to consider whether the land included in the 
proposed designation is developable. Additionally, the peer reviewer 
and two public commenters recommended consideration of environmental 
amenities in the Draft EA, including flood control and conveyance, 
benefits to other wildlife species, protection of green space, the 
development of public recreation areas, the increase in real estate 
values resulting from proximity to green space, increased revenues to 
the city in terms of visits by the public for wildlife viewing and 
outdoor recreation, generally increased recreational and amenity 
values, and increases in commodity prices.
    Our Response: We disagree with the peer reviewer's assertion that 
the estimated economic impacts of the critical habitat designation are 
unrealistically high. The Final EA relies upon land value data provided 
by the Lancaster County Assessor Department. These values are based on 
parcel market value assessments on comparable sales and its ``special 
value'' (i.e., agricultural value) assessments are based on soil types 
and production capabilities. Therefore, the land values used take into 
account all characteristics of the land, including any development 
restrictions.
    In regard to accrued environmental amenities or benefits, where 
sufficient information is available, the Final EA attempts to measure 
costs imposed on landowners or other users of the resource, less any 
offsetting gains experienced by these individuals associated with these 
conservation efforts.
    The analysis does not attempt to incorporate broader social and 
economic net benefits that may result incidentally from species 
conservation. The primary purpose of the rulemaking is the potential to 
enhance conservation of the species. As stated in the Draft EA, 
``[r]ather than rely on economic measures, the Service believes that 
the direct benefits of the proposed rule are best expressed in 
biological terms that can be weighed against the expected cost impacts 
of the rulemaking.'' Thus, the Service utilizes cost estimates from the 
economic analysis as one factor against which biological benefits are 
compared during the weighing process under section 4(b)(2) of the Act. 
The Service agrees that, to the extent that additional economic and 
social benefits such as protection of green space and development of 
public recreation areas, improvement of flood control, and enhanced 
quality of life, result from conservation measures for the beetle, such 
improvements could also benefit human communities.
    (14) Comment: One commenter stated that the Draft EA assumes 
critical habitat designation will include a 500-foot wide buffer, and 
all cropland included in critical habitat will be converted to pasture 
following critical habitat designation. The commenter pointed out that 
this assumption is incorrect, because the 500-foot buffer was put into 
place by the Lincoln-Lancaster County Planning Department, and is not 
required by the critical habitat designation. Further, the conversion 
of cropland to pasture is not a requirement of critical habitat, so 
this land use conversion assumption is not supported. The commenter 
also suggested the economic analysis should consider existing 
development restrictions, given that most of the proposed critical 
habitat is located within the 100- to 500-year floodplain.
    Our Response: The Final EA acknowledges some measures that protect 
the Salt Creek tiger beetle from development impacts, such as the 500-
foot wide buffer, were in place prior to the designation of critical 
habitat, and are not solely for conservation of the subspecies (ENTRIX 
2008a, p. 16). The Final EA clearly distinguishes between the ``without 
critical habitat'' and ``with critical habitat'' scenarios in Appendix

[[Page 17470]]

F. The ``without critical habitat'' scenario represents the baseline 
for the analysis, considering protections already accorded the 
subspecies, such as those under the Federal listing and other Federal, 
State, and local regulations. The ``with critical habitat'' scenario 
describes the incremental impacts associated specifically with the 
designation of critical habitat for the subspecies. The incremental 
conservation efforts and associated impacts are only those expected to 
occur from the designation of critical habitat for the subspecies. The 
costs associated with the protection of the saline wetlands, including 
the 500-foot buffer, are considered baseline impacts (ENTRIX 2008a, p. 
21).
    Given the federally listed status of the Salt Creek tiger beetle, 
landowners are likely to take necessary steps to avoid take of the 
species, to be in compliance with the Act. While all levels of crop 
cultivation may result in take of the beetle, grazing on pasture lands 
may result in take only if carried out beyond a certain threshold 
(i.e., overgrazing) (70 FR 58335, October 6, 2005). Given that the 
critical habitat mostly consists of saline wetlands and is not 
considered productive agricultural land, most landowners are likely to 
use their lands as pasture rather than cropland. Therefore, the Final 
EA's consideration of this land-use conversion in the economic analysis 
is reasonable.
    In response to the commenter's assertion on development 
restrictions, the economic analysis relies upon land value data 
provided by the Lancaster County Assessor Department. These values are 
based on parcel market value assessments on comparable sales, and the 
County's ``special value'' (i.e., agriculture value) assessments are 
based on soil types and production capabilities (ENTRIX 2008a, p. 19). 
Therefore, the land values used take into account all characteristics 
of the land, including any development restrictions.
    (15) Comment: One commenter stated that the public was unable to 
access the draft environmental assessment and Draft EA for review and 
comment.
    Our Response: The proposed rule (72 FR 70716) and the two documents 
that reopened the comment period (73 FR 31665; 74 FR 19167) indicated 
that the documentation for the proposed rule, including the Draft EA 
and draft environmental assessment, was available for public inspection 
on https://www.regulations.gov, or by appointment, during normal 
business hours, at our Nebraska Ecological Services Field Office. We 
included a mailing address and phone number for the office for anyone 
seeking further information.

Summary of Changes from the Proposed Rule

    We added another 138 ac (56 ha) of habitat to the original 
proposal, increasing the final critical habitat from 1,795 to 1,933 ac 
(727 to 782 ha). This additional area has been determined to contain 
features essential to the conservation of the subspecies along Little 
Salt Creek in Units 1, 2, and 3, and includes important saline seep and 
movement corridor habitats for the subspecies along Little Salt Creek. 
We are finalizing the following final critical habitat designation in 
accordance with section 4(b)(2) of the Act.

Critical Habitat

    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 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.
    Conservation, as defined under section 3 of the Act, means the use 
of all methods and procedures that are necessary to bring an endangered 
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 
pressures within a given ecosystem cannot be otherwise 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 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 
non-Federal landowners. Where a landowner seeks or requests Federal 
agency funding or authorization for an action that may affect a listed 
species or critical habitat, the consultation requirements of section 
7(a)(2) of the Act would apply, but even in the event of a destruction 
or adverse modification finding, the Federal action agency's and 
applicant's obligation under section 7(a)(2) of the Act 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 included in a critical habitat designation, habitat within 
the geographical area occupied by the species at the time it was listed 
must contain the physical and biological features that are essential to 
the conservation of the species, and will be included only if those 
features may require special management considerations or protection. 
Critical habitat designations identify, to the extent known using the 
best scientific and commercial data available, habitat areas that 
provide essential life cycle needs of the species (i.e., areas on which 
are found the physical and biological features laid out in the 
appropriate quantity and spatial arrangement for the conservation of 
the species). Under the Act and regulations at 50 CFR 424.12, we can 
designate critical habitat in areas outside the geographical area 
occupied by the species at the time of listing as critical habitat 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

[[Page 17471]]

available, to use primary and original sources of information as the 
basis for recommendations to designate critical habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information developed during the listing process for the species. 
Additional information sources may include the recovery plan 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 often dynamic, and species may move from one area to 
another over time. Furthermore, 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 area is 
unimportant or may not be required for recovery of the species.
    Areas that are important to the conservation of the species, but 
are outside the critical habitat designation, will continue to be 
subject to conservation actions implemented by the Service and other 
Federal agencies under section 7(a)(1) of the Act. They may also be 
subject to the regulatory protections afforded by the section 7(a)(2) 
jeopardy standard, as determined on the basis of the best available 
scientific 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), or other species conservation 
planning efforts if new information available at the time these 
planning efforts calls for a different outcome.

Physical and Biological Features

    In accordance with sections 3(5)(A)(i) and 4(b)(1)(A) of the Act 
and the regulations at 50 CFR 424.12, in determining which areas within 
the geographical area occupied by the species at the time of listing to 
designate as critical habitat, we consider the physical or biological 
features essential to the conservation of the species that may require 
special management considerations or protection. We consider the 
essential physical or biological features to be the primary constituent 
elements (PCEs) laid out in the appropriate quantity and spatial 
arrangement for the conservation of the species. These 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, or rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historic, geographical, and ecological 
distributions of a species.
    We derive the PCEs required for the Salt Creek tiger beetle from 
its biological needs as described below and in the proposed rule to 
designate critical habitat published in the Federal Register on 
December 12, 2007 (70 FR 70716). Additional information can also be 
found in the final listing rule published in the Federal Register on 
October 6, 2005 (70 FR 58335).
Space for Individual and Population Growth and for Normal Behavior

Space and Dispersal Requirements

    Salt Creek tiger beetles require non-vegetated stream banks and 
mid-channel areas, located adjacent to and between saline stream edges 
and barren salt flats in saline and freshwater wetlands, to allow 
movement for thermoregulation, hunting, and dispersal. Salt Creek tiger 
beetles move between habitats consisting of saline wetlands and streams 
(Allgeier et al. 2003, pp. 6-7), but open salt flats must be separated 
by a reasonable dispersal distance for the subspecies (Gowan and 
Knisley 2005, p. 9). Two Salt Creek tiger beetles were documented 
moving distances of 1,509 and 1,198 feet (ft) (460 and 365 meters (m)), 
respectively, between a saline stream and saline wetland, through a 
small assemblage of saline banks, presumably to meet the life 
requirements described above (Allgeier et al. 2003, pp. 6-7). Salt 
Creek tiger beetles also have been observed moving among salt flats and 
seeps along saline stream edges, using barren mid-channel and scoured 
bank habitats (Spomer 2005, pers. comm.; Harms 2003, pers. comm.). Mid-
channel habitats and scoured bank lines are created through natural 
hydrological processes in streams with sufficient flow to cause 
sediment scour, transport, and redeposition. Salt Creek tiger beetles 
can disperse from one mid-channel bar to the next, which enables them 
to move up and down stream courses in response to habitat changes. 
These short-range movement corridors are necessary to repopulate areas 
extirpated due to habitat loss or extreme weather events (Murphy et al. 
1990, pp. 41-51; Fahrig and Merriam 1994, pp. 50-59; Ruggerio et al. 
1994, pp. 364-372; Noss 2002, pp. 10-19).
    The Salt Creek tiger beetle probably has some long-range dispersal 
capability, an adaptation that has been documented in other tiger 
beetle species and is thought to enable colonization of transient or 
well-separated habitat that may be important for long-term species 
survival (USFWS 1994, p. 15). Although we have no data on long-range 
dispersal distances, the approximately 14-mi (22-km) separation between 
previously occupied habitats on Oak and Rock Creeks suggests that the 
Salt Creek tiger beetle may be capable of some level of aerial 
dispersal. Other tiger beetle species are capable of long-range 
dispersal. For example, mark-recapture studies completed for the 
Northeastern beach tiger beetle (Cicindela dorsalis) resulted in the 
recovery of marked tiger beetles 5 to 12 mi (8 to 19 km) from sites 
where they were marked (USFWS 1994, p. 15). Puritan tiger beetles (C. 
puritana) are known to have dispersed distances of 25 to 30 mi (40 to 
48 km) from known populations (USFWS 1993, p. 12). A population 
viability analysis for the Puritan tiger beetle in the Chesapeake Bay 
region also supports the theory that tiger beetles are capable of 
aerial dispersal (Gowan and Knisley 2005, pp. 8-22). In that analysis, 
the authors modeled beetle dispersal among subpopulations using data 
from the Northeastern beach tiger beetle (C. dorsalis). They concluded 
that populations less than 4 mi (6 km) apart tended to exchange 
individuals, which decreases the risk of extinction by allowing extant 
subpopulations to repopulate nearby extirpated areas (Gowan and Knisley 
2005, p. 11).
    We consider both short-range and long-range dispersal distances to 
be important factors in identifying features and habitats essential for 
the conservation of the Salt Creek tiger beetle. However, because 
specific data are not available to precisely define either short-range 
or long-range dispersal distances for this subspecies, we find that the 
best available science is Gowan and Knisley's (2005, pp. 8-22) study 
results, which indicate that Puritan tiger beetle populations separated 
by less than 4 mi (6 km) can

[[Page 17472]]

exchange individuals. We conclude that areas providing suitable 
habitat, located on more than a single stream, and separated by a 
maximum of 4 mi (6 km), should be maintained for the subspecies in 
order to decrease the risk of extinction by allowing extant 
subpopulations to exchange individuals and to repopulate nearby 
extirpated areas.
    Based on the information above, we identify non-vegetated 
streambanks and mid-channel areas, located adjacent to and between 
saline stream edges and barren salt flats in saline and freshwater 
wetlands, in assemblages that are within 4 mi (6 km) of one another as 
a PCE for this subspecies.
Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements

Moist, Barren Salt Flats

    Salt Creek tiger beetles require moist, barren salt flats for 
thermoregulation, reproduction, and foraging. Tiger beetle species are 
generally habitat-specific because of oviposition (the act of laying 
eggs) and larval sensitivities to soil moisture, salinity (measured by 
electroconductivity), composition, and temperature (Pearson 1988, pp. 
136-137; Pearson and Cassola 1992, p. 380). In field measurements, Salt 
Creek tiger beetles were found using areas with a mean soil 
electroconductivity of 2,504.1 conductivity per meter (mS/m), with a 
lower confidence limit of 2,016.0 mS/m and an upper confidence limit of 
2,992.2 mS/m (Allgeier 2005, p. 72). Field measurements also 
demonstrate that Salt Creek tiger beetles prefer mean soil moistures of 
47.6 percent, with a lower confidence limit of 43.5 percent and an 
upper confidence limit of 51.7 percent (Allgeier 2005, p. 72). The 
ability to occupy areas with specific habitat requirements (such as 
soil salinities and moisture levels) enables Salt Creek tiger beetles 
to coexist among conspecific or congeneric tiger beetles that have 
different specific habitat requirements.
    These reported soil salinity and moisture preferences are available 
within saline wetland and stream habitats in the Salt Creek basin. The 
following discussion provides specific details about saline soils, 
evaporative processes, and recharge zones required to create and 
maintain moist, barren salt flats within saline wetlands and streams.
    (a) Saline soils--Salmo and Saltillo soils or Lamo, Gibbon-Saltine, 
Obert, and Zoe soils with Salmo and Saltillo inclusions provide salt in 
sufficient content to result in the creation of salt barrens (U.S. 
Department of Agriculture 1980, p. 93). The Salt Creek tiger beetle is 
found in association with Salmo soils (Allgeier 2005, p. 18), and 
probably is also found in association with Saltillo soils when barren 
salt flats are present. Although Salmo and Saltillo soils are known to 
contain sufficient salt to result in the creation of salt barrens, 
Salmo soils tend to be better drained than Saltillo soils (NRCS 2009, 
pp. 3, 6). However, for the purpose of this rule, we will consider both 
of these classes of soils to be used by the Salt Creek tiger beetle. 
Soils in stream channels are not mapped because they can take on saline 
characteristics as they pass through areas with the saline soils 
described above, or through areas that may have historically contained 
saline soils (e.g., urban areas where the saline soils were covered 
over by fill materials and thus not mapped).
    (b) Evaporation--The soils identified above must have 
electroconductivity within the range of 2,016.0 mS/m to 2,992.2 mS/m to 
be used by the Salt Creek tiger beetle. In addition, the process of 
evaporation also must occur to create exposed salt on the soil surface, 
resulting in the formation of barren salt flats. Specifically, 
evaporation of groundwater (through differential hydraulic pressures) 
and surface water from the soils listed above results in the creation 
of a thin salt crust on the soil surface (Schainost 2005, pers. comm.).
    (c) Recharge Zone--Freshwater and saline wetlands contiguous with 
Salt Creek tiger beetle habitat function as a recharge zone for barren 
salt flats and stream banks by regulating surface water flows that are 
often charged with sediment and freshwater. Without recharge zones, 
barren salt flats and stream banks required by Salt Creek tiger beetles 
do not persist (LaGrange 2005, pers. comm.; Stutheit 2005, pers. 
comm.). A reduction in salinity concentration can result in the 
germination of aggressive invasive species such as cattail (Typha 
angustifolia) and reed canarygrass (Phalaris arundinacea), which are 
tolerant of a somewhat reduced salt content. These plant species shade 
previously open, sunny areas (i.e., barren salt flats and stream banks) 
required by Salt Creek tiger beetles for thermoregulating, foraging, 
and ovipositing (Fritz 2001, pers. comm.). Changes in salinity and 
hydrology may alter the abundance of prey and cause the loss of 
suitable larval habitat for saline wetland/stream-dependent tiger 
beetles, including the Salt Creek tiger beetle (Hoback et al. 2000, pp. 
184-186). Increased vegetative encroachment is the primary factor 
attributed to the extirpation of several populations of other Cicindela 
species (e.g., C. abdominals and C. debilis) (Knisley and Hill 1992, 
pp. 135-142), and is one of the main threats to the endangered Ohlone 
tiger beetle (C. ohlone) (66 FR 0340).
    Based on the information above, we identify moist, barren salt 
flats with appropriate soil characteristics to be a PCE for this 
subspecies.

Water Availability and Hydrologic Regime

    Salt Creek tiger beetles require water to prevent larval 
desiccation, to maintain moist conditions at larval burrows for 
breeding and foraging activities, and for drinking (Spomer and Higley 
1993, p. 396). Adult Salt Creek tiger beetles are confined to moist, 
muddy areas within a few meters of wetlands and stream edges, and 
larval burrows are only found in association with hydrated salt flats 
located along saline stream edges and saline wetlands (Spomer 2005, 
pers. comm.). A natural hydrologic regime resulting in annual high 
flows in saline streams in the early spring and summer is essential to 
maintain these areas, and to provide groundwater or surface water 
sources for the Salt Creek tiger beetle. Further, natural elevation 
changes in groundwater levels are important to hydrate saline wetlands 
located on the floodplain.
    Larvae of the Salt Creek tiger beetle have adapted to elevated 
flows, inundation, and anaerobic conditions resulting from 
precipitation events that can occur during the summer (e.g., localized 
thunderstorms). This adaptation is thought to provide access to limited 
prey resources in areas where other predacious insects cannot compete; 
in addition, it may help the Salt Creek tiger beetle avoid parasites 
and other insect predators (e.g., robberflies) after flows recede 
(Hoback 2005, pers. comm.). Salt Creek tiger beetle larvae likely plug 
their burrows and switch from aerobic to anaerobic respiration to avoid 
short-duration inundation by floods (Spomer 2005, pers. comm.). 
Although no studies have confirmed these hypotheses, Hoback et al. 
(1998, p. 31) found that larvae of Cicindela togata, a tiger beetle 
found in close association with the Salt Creek tiger beetle, were able 
to survive without oxygen for an average of 6 days at 25 \o\C (57 
\o\F). An adaptation to survive without oxygen during floods may allow 
the Salt Creek tiger beetle to persist along stream systems subject to 
regular flooding cycles. Brust et al. (2005, pp. 11-16) concluded that 
C.

[[Page 17473]]

hirticollis is able to survive along river systems subject to regular 
flooding cycles because its larvae could survive several days of 
hypoxia, although extended inundation results in decline of the 
species.
    Based on the information above, we identify a natural hydrologic 
regime resulting in annual high flows in saline streams in the early 
spring and summer, and natural elevation changes in groundwater levels 
to hydrate saline wetlands located on the floodplain as a PCE for this 
subspecies.

Prey Availability

    Salt Creek tiger beetles require an abundant and diverse prey base 
consisting of flying and non-flying invertebrates. Tiger beetles have 
been observed to eat insects from many orders and families (Larochelle 
1974, pp. 21-43). Most common are prey belonging to the orders 
Coleoptera, Orthoptera, Hemiptera, Hymenoptera, Odonata, Diptera, and 
Lepidoptera. Ants (Formicidae) are the most commonly observed prey of 
adult Salt Creek tiger beetles in the field (Allgeier 2005, p. 5). 
Although adults can prey on a greater diversity of available prey than 
larvae, both adults and larvae are predators of similar-sized insects. 
Adults can capture flying insects; larval prey consists only of insects 
and arthropods living on the soil surface that wander within striking 
distance of their burrows (Allgeier 2005, p. 5; Spomer 2005, pers. 
comm.). Typical prey of larval tiger beetles includes dragonflies 
(Shelford 1908, pp. 157-184; McNamara 1922, pp. 241-246; Smith 1971, p. 
80), millipedes (Labonte and Johnson 1988, pp. 53-54), earthworms, and 
amphibians (Larochelle and Lariviere 2001, pp. 41-122).
    Based on the information above, we identify the presence of 
abundant and diverse flying and non-flying invertebrate prey species as 
a PCE for this subspecies.

Primary Constituent Elements (PCEs) for the Salt Creek Tiger Beetle

    Under the Act and its implementing regulations, we are required to 
identify the physical and biological features within the geographical 
area occupied by the Salt Creek tiger beetle at the time of listing, 
that are essential to the conservation of the subspecies, and which may 
require special management considerations or protection. The physical 
and biological features are those PCEs laid out in a specific spatial 
arrangement and quantity determined to be essential to the conservation 
of the subspecies. We are designating critical habitat in areas within 
the geographical area occupied by the subspecies at the time of 
listing, and continue to be occupied today, and that contain the PCEs 
in the quantity and spatial arrangement to support life history 
functions essential for the conservation of the subspecies. We are 
designating areas outside the geographical area occupied by the 
subspecies at the time of listing that are not occupied, but are 
essential to the conservation of the subspecies.
    We believe conservation of the Salt Creek tiger beetle is dependent 
upon multiple factors, including the conservation and management of 
areas to maintain ``normal'' ecological functions where existing 
populations survive and reproduce. The areas designated as critical 
habitat provide all of the physical or biological features essential 
for the conservation of the subspecies. Based on the above needs and 
our current knowledge of the life history, biology, and ecology of the 
subspecies and the habitat requirements for sustaining the essential 
life history functions of the subspecies, we have determined the PCEs 
for the Salt Creek tiger beetle are:
    (1) Non-vegetated streambanks and mid-channel areas, located 
adjacent to and between saline stream edges and barren salt flats in 
saline and freshwater wetlands, in assemblages that are within 4 mi (6 
km) of one another.
    (2) Moist, barren salt flats with:
    (a) Salmo and Saltillo soils or Lamo, Gibbon-Saltine, Obert, and 
Zoe soils with Salmo and Saltillo inclusions;
    (b) Soil electroconductivity ranging from 2,016.0 mS/m to 2,992.2 
mS/m;
    (c) Soil moisture ranging from 43.5 percent to 51.7 percent; and
    (d) Differential hydraulic pressures that create evaporation and 
result in exposed salt on soil surfaces.
    (3) A natural hydrologic regime resulting in annual high flows in 
saline streams in the early spring and summer, and natural elevation 
changes in groundwater levels to hydrate saline wetlands located on the 
floodplain.
    (4) The presence of abundant and diverse flying and non-flying 
invertebrate prey species belonging to the orders Coleoptera, 
Orthoptera, Hemiptera, Hymenoptera, Odonata, Diptera, or Lepidoptera.
    With this designation of critical habitat, we intend to conserve 
the physical and biological features that are essential to the 
conservation of the subspecies, through the identification of the 
appropriate quantity and spatial arrangement of the PCEs sufficient to 
support the life history functions of the subspecies. All occupied 
units designated as critical habitat contain the PCEs in the 
appropriate quantity and spatial arrangement essential to the 
conservation of this subspecies and support multiple life processes for 
the Salt Creek tiger beetle.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing that contain the physical and biological features essential 
to the conservation of the species may require special management 
considerations or protection. Special management is required in these 
areas to reduce threats. Threats common to all four critical habitat 
units for the Salt Creek tiger beetle include: (a) Stream 
channelization and bank armoring; (b) wetland draining and filling 
(including excessive sedimentation); (c) excessive freshwater input; 
and (d) overgrazing (70 FR 58335, October 6, 2005). The first three of 
the above threats are caused primarily by urban development and 
agricultural practices in the watershed.
    Stream channelization and bank armoring projects in the area of all 
four critical habitat units have resulted in headcutting (a sharp break 
in the profile of a stream which forms an in-channel scarp called a 
headcut) and entrenchment (lowering of the stream bed into a restricted 
channel) of Little Salt and Rock Creeks. These impacts have the effect 
of lowering the water table in the local area, resulting in the 
drainage of adjacent saline and freshwater wetlands. The ultimate 
effect has been the gradual lowering of the water table and subsequent 
loss of evaporation processes essential for the development of moist, 
barren salt flats. Stream entrenchment, a direct consequence of stream 
channelization and bank armoring projects, has resulted in bank 
sloughing along saline streams. Bank sloughing, in turn, smothers 
saline seeps and salt flats used by Salt Creek tiger beetles. Bank 
armoring projects in all four units have resulted in smothered barren 
salt flats and seeps along saline streams. Stream channelization and 
bank armoring continue to be significant threats to Salt Creek tiger 
beetles in all four critical habitat units.
    Wetland draining and filling projects, including ditch excavation 
and drainage tile installation, substantially affect Salt Creek tiger 
beetle habitat, rendering formerly occupied habitat unusable. In 
addition, these projects often lead to the conversion of wetlands to 
other land uses (e.g., hay production or pasture, and urban 
development), thereby

[[Page 17474]]

limiting restoration potential. Saline and freshwater wetlands have 
been filled as a result of sediment deposits from local runoff events. 
These deposits contain excessive nutrients, encouraging colonization by 
aggressive, invasive vegetation that is tolerant of saline conditions 
(i.e., cattail or reed canarygrass).
    Excessive surface water runoff from nearby development has resulted 
in the dilution of saline wetlands, loss of barren salt flats, and 
modifications to site hydrological characteristics. Excessive sediment 
or freshwater runoff can encourage vegetation encroachment on barren 
salt flats, reducing the long-term viability of the area for Salt Creek 
tiger beetle use. These impacts have occurred on all four critical 
habitat units.
    Livestock with access to saline streams trample larvae and larval 
habitat on salt-encrusted soil surfaces associated with barren salt 
flats and seeps. Livestock continue to pose a significant threat to 
Salt Creek tiger beetles, primarily because too many animals are often 
grazed in a given area, and they are not prevented from lingering in 
stream habitat. Additionally, overgrazing can encourage soil erosion 
and smothering of larval habitat in saline wetland and saline stream 
edges. Adverse impacts from excessive livestock grazing have occurred 
at the Upper Little Salt Creek North and Little Salt Creek--Arbor Lake 
Units.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(2) of the Act, we use the best 
scientific and commercial data available in determining within the 
geographical area occupied at the time of listing the specific areas on 
which are found the features essential to the conservation of the Salt 
Creek tiger beetle which may require special management considerations 
or protection, as well as determining if any specific areas outside the 
geographical area occupied by the subspecies are essential for the 
conservation of the Salt Creek tiger beetle. Important sources of 
information included the available literature and information from 
biologists with the NGPC and University of Nebraska at Lincoln.
    We also have reviewed available information that pertains to the 
habitat requirements of this subspecies, including material and data 
from 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; and regional Geographic Information System coverages.
    The Salt Creek tiger beetle has one of the most restricted ranges 
of any insect in the United States (Spomer and Higley 1993, p. 392), 
and the habitat currently occupied by the subspecies is highly limited 
and isolated. Surveys conducted over a 15-year period establish that 
the Salt Creek tiger beetle is extremely rare, numbering only in the 
low hundreds, and confined to three small populations along a single 
drainage (Little Salt Creek) in eastern Nebraska (see the October 6, 
2005, final listing rule for more information on population status of 
the Salt Creek tiger beetle (70 FR 58335)). Because of low population 
numbers and the limited number of populations, both of which place the 
subspecies at a high risk of extinction and make it highly susceptible 
to stochastic events, designated critical habitat includes all three 
extant populations. The close proximity of the three currently occupied 
areas on Little Salt Creek (within 4 mi (6.4 km) of each other) 
increases the risk of extinction of the subspecies due to a single 
human or natural event. Therefore, it is essential to the conservation 
of the subspecies to ensure the existence of a potential refugium in a 
different watershed than the three currently occupied units, should an 
event or series of events threaten the existence of the remaining three 
populations.
    We have identified a currently unoccupied area on Rock Creek 
(associated with the Jack Sinn Wildlife Management Area of the NGPC) as 
an additional unit for critical habitat designation. This area was 
known to be occupied as recently as 1998, and contains all the PCEs in 
the appropriate quantity and spatial arrangement essential to the 
conservation of the subspecies. The Jack Sinn--Rock Creek Unit (Unit 4) 
is a location where the subspecies can be reintroduced, and where it 
would not be susceptible to human or natural events that occur on 
Little Salt Cree