Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Salt Creek Tiger Beetle (Cicindela nevadica lincolniana, 58335-58351 [05-20049]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 70, Number 193 (Thursday, October 6, 2005)]
[Rules and Regulations]
[Pages 58335-58351]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-20049]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AJ13


Endangered and Threatened Wildlife and Plants; Determination of 
Endangered Status for the Salt Creek Tiger Beetle (Cicindela nevadica 
lincolniana)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
endangered status for the Salt Creek tiger beetle (Cicindela nevadica 
lincolniana), pursuant to the Endangered Species Act (Act) of 1973, as 
amended (Act). This species is endemic to the saline wetlands of 
eastern Nebraska (NE) and associated streams in the northern third of 
Lancaster County and southern margin of Saunders County. Only three 
small populations of this subspecies remain, and the known adult 
population size in 2005 was only 153 individuals. This final rule 
extends Federal protection and recovery provisions of the Act to the 
Salt Creek tiger beetle.

DATES: This final rule is effective November 7, 2005.

ADDRESSES: The complete file for this final rule is available for 
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, Second Floor, Grand Island, 
NE 68801.

FOR FURTHER INFORMATION CONTACT: Mr. Steve Anschutz, Field Supervisor, 
at the above address (telephone (308) 382-6468, extension 12; facsimile 
(308) 384-8835)).

SUPPLEMENTARY INFORMATION:

Background

    Please see the proposed rule to list the Salt Creek tiger beetle as 
endangered (February 1, 2005; 70 FR 5101) for detailed information on 
the subspecies' taxonomy, natural history, distribution, and population 
status. We include a brief synopsis of that information here, along 
with new information that has been obtained since publication of the 
proposed rule.
    The Salt Creek tiger beetle (Cicindela nevadica lincolniana) is an 
active, ground-dwelling, predatory insect that captures small 
arthropods in a ``tiger-like'' manner by grasping prey with its 
mandibles (mouthparts). Salt Creek tiger beetle larvae live in 
permanent burrows in the ground. They are voracious predators, 
fastening themselves by means of abdominal hooks to the tops of their 
burrows and rapidly extending outward to seize passing prey. Adult Salt 
Creek tiger beetle are metallic brown to dark olive-green above, with a 
metallic dark green underside, and measure 1.3 centimeters (cm) (0.5 
inch (in.)) in total length.

Taxonomy

    The Salt Creek tiger beetle is a member of the family Cicindelidae, 
genus Cicindela. Eighty-five species and more than 200 subspecies of 
tiger beetles in the genus Cicindela are known from the United States 
(Boyd et al. 1982, Freitag 1999). Originally, the Salt Creek tiger 
beetle was described by Casey (1916) as a separate species, C. 
lincolniana. Willis (1967) identified C. n. lincolniana as a subspecies 
of C. nevadica, which evolved from C. n. knausii. This is the currently 
accepted taxonomic classification. The evolution of C. n. lincolniana 
was a result of its isolation some time after the Kansan glaciation 
(435,000 to 300,000 years before the present), but possibly during the 
Yarmouth glaciation (300,000 to 265,000 years before the present). 
Busby (2003) recently examined populations of C. nevadica and confirmed 
that C. n. lincolniana is distinctive from other populations of C. 
nevadica in the central Great Plains.

Life History

    Allgeier et al. (2004) and Spomer et al. (2004a) indicated that the 
Salt Creek tiger beetle has a 2-year life cycle, not uncommon for tiger 
beetles. Spomer and Higley (2001) and Spomer et al. (2004a) described 
the life cycle of the Salt Creek tiger beetle in detail through egg, 
larval, and adult stages. Adults are first observed as early as the end 
of May or as late as mid-June, peak in late June or early July, and 
disappear by mid-to late July. By August, almost all adults have died 
in the field (Spomer et al. 2004a). Females lay their eggs along 
sloping banks of creeks in areas where the salt layer is exposed in the 
soil horizon, in barren salt flats of saline wetlands, or along saline 
stream edges that are found in close association with water, near a 
seep or stream. During the night, female Salt Creek tiger beetles lay 
about 50 eggs in burrows (Farrar 2003, Allgeier et al. 2004). After the 
egg hatches and the young larva emerges from the burrow, the larva digs 
a burrow and uses its head to scoop out soil. Larval burrows can occur 
throughout a saline streambank and on barren salt flats of saline 
wetlands. Based on field observations, numerous saline seeps cause 
variation in soil moisture and salinity in the streambanks that allow 
burrows to occur away from the water's edge (W. Allgeier, pers. comm. 
2005).
    The small larva waits at the top of its burrow and ambushes prey 
that passes near the burrow entrance. The larva will plug its burrow 
and retreat inside during periods of high water, very hot weather, or 
very dry conditions. As the larva grows, it molts to a larger instar (a 
life stage between molts), enlarging and lengthening its burrow. For 
the most part, a Salt Creek tiger beetle larva will remain active until 
cold weather, at which time it plugs its burrow and hibernates. The 
Salt Creek tiger beetle has three instars. It probably overwinters as a 
third instar, pupates in May, and emerges as an adult. Before pupation, 
the larva seals its burrow entrance and digs a side chamber about 5 to 
8 cm (2 to 3 in.) below the soil surface. After the adult emerges from 
the pupa, it remains in the chamber until its cuticle hardens.

Habitat

    Tiger beetle species occur in many different habitats, including 
riparian habitats, beaches, dunes, woodlands, grasslands, and other 
open areas (Pearson 1988; Knisley and Hill 1992). Individual tiger 
beetle species are generally highly habitat-specific because

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of oviposition (i.e., the act of laying eggs) and larval sensitivity to 
soil moisture, composition, and temperature (Pearson 1988, Pearson and 
Cassola 1992). A common component of tiger beetle habitat appears to be 
open sunny areas for hunting and thermoregulation (an adaptive behavior 
to use sunlight or shade to regulate body temperature) (Knisley et al. 
1990, Knisley and Hill 1992).
    The Salt Creek tiger beetle occurs in saline wetlands--on exposed 
saline mudflats and along mud banks of streams and seeps that contain 
salt deposits (Carter 1989, Spomer and Higley 1993, LaGrange 1997). 
These saline habitats occur within the floodplain of Salt Creek and its 
tributaries in northern Lancaster and southern Saunders Counties. The 
habitats, especially the saline wetlands, receive their salinity from 
groundwater passing through an underground rock formation containing 
salts deposited by an ancient sea that once covered Nebraska (LaGrange 
1997). Saline wetlands of eastern Nebraska are characterized by saline 
soils and halophytes (plants adapted to saline conditions). They 
usually contain a central area that is devoid of vegetation and, when 
dry, exhibit salt-encrusted mudflats (barren salt flats) (LaGrange 
1997). These saline wetlands are used by Salt Creek tiger beetles and 
numerous other saline-adapted insects.
    The Salt Creek tiger beetle has very narrow habitat requirements 
for breeding; they occur in saline wetlands, on exposed saline mud 
flats and gravel bars, or along mud banks of streams and seeps that 
contain salt deposits and are sparsely vegetated (Carter 1989; Spomer 
and Higley 1993; LaGrange 1997; Nebraska Game and Parks Commission 
(NGPC) 1999; Spomer et al. 2004a). Larvae have been found only on the 
moist salt-encrusted banks of Little Salt Creek in northern Lancaster 
County (Spomer et al. 2004a). The density of larval burrows decreases 
as vegetative cover increases (S. Spomer, University of Nebraska--
Lincoln (UNL), pers. comm. 2002). Spomer et al. (2004a) indicated that 
adults show little flexibility in their selection of breeding habitat.
    The earliest emerging adults sometimes move from creek banks to the 
salt flats, presumably for early prey. However, a week or two into 
emergence, this behavior stops and adults are found almost exclusively 
in wetter areas, like creek edges or seeps along the creek (Spomer et 
al. 2004a). During peak emergence, adults often wander from their 
emergence sites, presumably looking for new areas to colonize or search 
for prey (Spomer et al. 2004a). It is during this time that adults 
often appear on sand or gravel bars, or on less saline soils along the 
stream. Salt Creek tiger beetles require these open barren areas to 
construct larval burrows, thermoregulate, and forage, and for use as 
dispersal corridors (Spomer and Higley 1993; L. Higley, UNL, pers. 
comm. 2002; S. Spomer, UNL, pers. comm. 2002). The Salt Creek tiger 
beetle is adapted to brief periods of high-water inundation and highly 
saline conditions (Spomer and Higley 1993).

Distribution and Status Overview

    The Salt Creek tiger beetle currently has one of the most 
restricted ranges of any insect in the United States (Spomer and Higley 
1993, Spomer et al. 2004a); it only occurs along limited segments of 
Little Salt Creek and adjacent remnant salt marshes in Lancaster 
County, Nebraska. To assess the historical and current distributions 
and populations of Salt Creek tiger beetle, we have analyzed private 
and public insect collections, NGPC's Heritage database records, and 
surveys conducted over the past 15 years, as well as sought the 
professional opinions of UNL entomologists who have studied or are 
studying the Salt Creek tiger beetle. Please see the proposed rule (70 
FR 5101; February 1, 2005) for additional details about the historical 
records we consulted, and the historical distribution of the 
subspecies.

Recent Distribution and Abundance

    Pearson and Cassola (1992) found that tiger beetle population size 
can be accurately estimated through visual counting due to the relative 
ease of observing and counting individuals, and because of their 
specialized habitat requirements. Visual counts have limitations (Horn 
1976), but if they are conducted in a similar manner every year, they 
can provide relative population estimates and a good estimate of the 
health and stability of the populations surveyed (Allgeier et al. 
2003). Intensive visual surveys conducted from 1991 through 2005 found 
Salt Creek tiger beetles at a total of 13 sites; although beetles were 
not found, nor were surveys conducted, at all 13 sites in all 15 years 
(Spomer et al. 2002, 2004a, 2004b; S. Spomer, UNL, pers. comm. 2005). 
Please see the proposed rule (70 FR 5101) for a description of the 
visual survey techniques used. In addition to visual count surveys, in 
2002, researchers undertook a mark/recapture study of the Little Salt 
Creek--Arbor Lake population. The small sample size hampered the mark/
recapture study, thereby making conclusions about population size 
uncertain. This study has not been continued in subsequent years due to 
limited resources. Results obtained from this study in 2002 are 
discussed in the proposed rule (70 FR 5101).
    Surveys conducted over a 15-year period establish that the Salt 
Creek tiger beetle is an extremely rare insect, numbering only in the 
hundreds and confined to an extremely small range. Visual surveys 
conducted from 1991 to 2005 show substantial annual fluctuations of 
total adult tiger beetles with 229, 150, 115, 473, 637, 631, 550, 308, 
271, 309, 519, 777, 745, 558, and 153 found each year, respectively, 
although not all sites were surveyed in all years (Spomer and Higley 
1993; Spomer et al. 1997, 1999, 2001, 2002, 2004a, 2004b; Allgeier et 
al. 2003, S. Spomer, UNL, pers. comm. 2005). The 2005 surveys found 
only 153 Salt Creek tiger beetles. This ranks as the third lowest count 
since 1991 and the lowest in the past 12 years. Over the last two 
years, the total number of Salt Creek tiger beetles observed through 
visual surveys has declined by about 80 percent (from 745 individuals 
in 2003 to 153 individuals in 2005).
    We determined that some of the 13 ``sites'' could be combined into 
``populations'' of Salt Creek tiger beetles when the following criteria 
were met--(1) close proximity of sites to each other (i.e., nearby, 
contiguous, or neighboring); (2) distances less than 805 meters (m) 
(2,640 feet (ft)) between sites; and (3) the presence of both suitable 
saline wetland (i.e., barren salt flats) and stream (saline edges) 
habitats that form a saline wetland/stream complex. The distance in 
criteria 2 above (805 m (2,640 ft)) is based on the 2002 mark/recapture 
study by Allgeier et al. (2003), which established that Salt Creek 
tiger beetles can move among nearby suitable habitats, as well as the 
distance at which Salt Creek tiger beetles may be attracted to 
artificial sources of light.
    On the basis of the above criteria, our evaluation of the 13 survey 
sites resulted in the delineation of 6 different populations of Salt 
Creek tiger beetles, half of which have been extirpated since annual 
surveys began in 1991 (a population is considered extirpated after 2 
consecutive years of negative survey results). The six Salt Creek tiger 
beetle populations, including the three that have been extirpated, are 
described below in order of abundance based on visual surveys conducted 
from 1991 to 2005--(1) Little Salt Creek--Arbor Lake; (2) Little Salt 
Creek--Roper; (3) Upper Little Salt Creek--North; (4) Upper Little Salt 
Creek--South; (5) Jack Sinn

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Wildlife Management Area (WMA); and (6) Capitol Beach.
    The last 3 populations on the above list are considered to be 
extirpated. The Upper Little Salt Creek--South population was located 
approximately 5 km (3 mi) upstream from the Little Salt Creek--Arbor 
Lake population. Degraded and nonfunctioning saline wetlands exist 
adjacent to Little Salt Creek, and although once devoid of vegetation, 
saline stream edge habitats are now vegetated at this site. The Upper 
Little Salt Creek--South population is considered extirpated because no 
Salt Creek tiger beetles have been found there since 1995. The Jack 
Sinn WMA population was made up of one survey site located on Rock 
Creek in southern Saunders and northern Lancaster Counties, 
approximately 20 km (10 mi) northeast of the Little Salt Creek--Arbor 
Lake population. Salt Creek tiger beetles from sites comprising the 
Jack Sinn WMA population have not been found since 1998 (Spomer et al. 
1999, 2001, 2002, 2004a, 2004b; Allgeier et al. 2003, S. Spomer, UNL, 
pers. comm. 2005). This population is considered extirpated because no 
Salt Creek tiger beetles have been found there since 1998. Capitol 
Beach was once one of the largest saline wetland tracts in eastern 
Nebraska, with a size of approximately 150 ha (400 ac) (Cunningham 
1985). Museum records between 1900 and 1972 indicate large numbers of 
Salt Creek tiger beetles at this site historically. In 1984, 
researchers conducted visual searches for the Salt Creek tiger beetle 
at Capitol Beach and other sites that appeared to provide suitable 
habitat (Spomer and Higley 2001). They found a low number of adults at 
Capitol Beach and noted that the habitat had been degraded (Spomer and 
Higley 1993). Today, all that remains of suitable habitat at Capitol 
Beach is a 10- to 20-m (40- to 50-ft) wide ditch that parallels 
Interstate 80 for approximately 0.8 km (0.5 mi), located southwest of 
the Interstate 80 and Airport Interchange. No individuals have been 
found at Capitol Beach since 1998 (Spomer et al. 2002, 2004a, 2004b; 
Allgeier et al. 2003; S. Spomer, UNL, pers. comm. 2005), leading us to 
conclude that this population is now extirpated. Please see the 
proposed rule (70 FR 5101) for additional information on these 3 
populations.
    We briefly describe the remaining 3 extant populations, with 
emphasis on new information. Please see the proposed rule (70 FR 5101) 
for additional details on these 6 populations.

Little Salt Creek--Arbor Lake Population

    The Little Salt Creek--Arbor Lake area is a large, relatively 
intact saline wetland complex that contains the largest population of 
Salt Creek tiger beetles. The Little Salt Creek--Arbor Lake population 
is located approximately 1.6 km (1 mi) north of the Interstate 80 and 
North 27th Street Interchange on the northern city limits of Lincoln, 
NE. It exists along the saline stream edge of Little Salt Creek and on 
the barren salt flats of an adjacent saline wetland. This population 
was monitored from 1991 to 2005, and the adult population averaged 315 
individuals per year over that 15-year period (Spomer and Higley 1993; 
Spomer et al. 1997, 1999, 2001, 2002, 2004a, 2004b; Allgeier et al. 
2003; S. Spomer, UNL, pers. comm. 2005). The 2005 survey results were 
the third lowest count since 1991 and the lowest in the past 12 years. 
Over the last two years, visual surveys of Salt Creek tiger beetles in 
the Little Salt Creek--Arbor Lake population declined by about 80 
percent.

Little Salt Creek--Roper Population

    The Little Salt Creek--Roper population is the second largest 
remaining population of Salt Creek tiger beetles, based on visual 
surveys conducted from 1994 to 2005. This population is located 
immediately south of the Interstate 80 and North 27th Street 
Interchange, approximately 1.6 km (1 mi) downstream of the Little Salt 
Creek--Arbor Lake population. Similar to the Little Salt Creek--Arbor 
Lake population, this population is associated with a saline wetland 
and stream complex located along Little Salt Creek. Visual surveys were 
conducted from 1994 to 2005, and the population counts were 54, 161, 
151, 144, 45, 55, 80, 85, 258, 162, 154, and 22 respectively (Spomer et 
al. 1997, 1999, 2001, 2002, 2004a, 2004b; Allgeier et al. 2003, S. 
Spomer, UNL, pers. comm. 2005). The 2005 survey results were the lowest 
count since monitoring began. Over the last two years, visual surveys 
of Salt Creek tiger beetles in the Little Salt Creek--Roper population 
declined by about 86 percent.

Upper Little Salt Creek--North Population

    The Upper Little Salt Creek--North population is the third and last 
extant (i.e., existing) population of Salt Creek tiger beetles. This 
population is located approximately 7.2 km (4.5 mi) upstream from the 
Little Salt Creek--Arbor Lake population, and exists only on the saline 
stream edges of Little Salt Creek. Although former saline wetlands 
(i.e., barren salt flats) exist adjacent to this population, these 
wetlands are degraded (drained because of the incisement of Little Salt 
Creek) and no longer provide suitable habitat for the Salt Creek tiger 
beetle. This population encompasses four sites along Little Salt Creek 
that were surveyed at various times during the period 1991 to 2005. 
Over the course of the 15-year survey period, 2 of the survey sites 
that comprise this population were surveyed at least 10 times. From 
1991 to 1996, the number of adult beetles found in the Upper Little 
Salt Creek--North population averaged 32 individuals per year (Spomer 
and Higley 1993; Spomer et al. 1997). Since then, the number of adult 
beetles surveyed in the population has averaged about 6 individuals per 
year; the total number found in 2005 was 16 adult individuals (Spomer 
and Higley 1993; Spomer et al. 1997, 1999, 2001, 2002, 2004a, 2004b; 
Allgeier et al. 2003; S. Spomer, UNL, pers. comm. 2005). Higley and 
Spomer (pers. comm. 2002) presumed that this population was threatened 
with extirpation in the near future because of the low and decreasing 
number of adults found during surveys.

Conclusion of Salt Creek Tiger Beetle Population Review

    The Salt Creek tiger beetle, highly specialized in habitat use, has 
probably always had a localized distribution. Visual surveys and mark-
recapture results indicate that the number of Salt Creek tiger beetles 
is extremely small, even when compared to other federally listed tiger 
beetle taxa. Population numbers are even smaller than the federally 
listed threatened Northeastern beach tiger beetle (Cicindela dorsalis 
dorsalis) and Puritan tiger beetle (C. puritana). From 1989 to 1992, 
the number of Northeastern beach tiger beetles found during annual 
surveys at 65 sites in Maryland and Virginia ranged from 9,846 to more 
than 17,480 beetles (USFWS 1994). Surveys of Puritan tiger beetles in 
Maryland in 1989, 1991, 1992, and 1993 found an average of 6,389 
beetles at 15 sites annually (USFWS 1993). Both the Northeastern beach 
tiger beetle and Puritan tiger beetle are well-studied insects and were 
listed as threatened under the Act in 1989 (55 FR 32088).
    Museum collections and surveys conducted from 1991 through 2005 
show that the number of known populations has declined from 6 to 3 in 
the last 9 years. Salt Creek tiger beetles were last found in the Upper 
Little Salt Creek--South population in 1995, and

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no individuals have been found in either the Jack Sinn WMA or the 
Capitol Beach populations since 1998. Based on our analysis of the best 
available scientific information, including private and public insect 
collections, NGPC's Heritage database records, surveys conducted over 
the past 15 years, and professional opinions of UNL entomologists who 
have studied or are studying the Salt Creek tiger beetle, we conclude 
that the number of Salt Creek tiger beetle populations is declining and 
that the three remaining populations are immediately threatened with 
extinction. This is discussed further below in the Summary of Factors 
Affecting the Species section of this rule.

Previous Federal Action

    For more information on previous Federal actions concerning the 
Salt Creek tiger beetle prior to 2002, please refer to the proposed 
rule to list the subspecies as endangered (70 FR 5101; February 1, 
2005). On October 7, 2002, as part of an agreement regarding other 
species, the U.S. Department of the Interior reached an out-of-court 
settlement with several conservation organizations and agreed to make a 
final determination for listing the Salt Creek tiger beetle by no later 
than September 30, 2005. In the May 4, 2004, Candidate Notice of Review 
published in the Federal Register (69 FR 24876), the Salt Creek tiger 
beetle remained as a priority 3 candidate for Federal listing. On 
February 1, 2005, we published a proposed rule in the Federal Register 
(70 FR 5101) to list the Salt Creek tiger beetle as endangered. This 
final rule complies with the court order. We have updated the proposed 
rule to reflect new information concerning changes in distribution, 
status, and threats to the subspecies since publication of the proposed 
rule.

Summary of Comments and Recommendations

    In the proposed rule published on February 1, 2005, we requested 
interested parties to submit factual reports or information that might 
contribute to the development of a final rule. A 60-day comment period 
closed on April 4, 2005. We contacted appropriate Federal agencies, 
State agencies, county and city governments, scientists, and other 
interested parties to request information and comments. A newspaper 
notice was printed in the Lincoln Journal Star on February 20, 2005. 
There were no requests for a public hearing during the comment period. 
Finally, we requested peer review in compliance with our peer review 
policy (59 FR 34270; July 1, 1994).
    During the public comment period, we received written comments 
(i.e., letters, facsimiles, and electronic messages) from 64 
individuals, businesses, schools, organizations, and State and local 
government entities; and 1 request for an extension of the comment 
period. In all, 56 commenters supported the protection of the Salt 
Creek tiger beetle through a Federal listing, while 8 commenters 
opposed the listing. Of the 56 commenters supporting the listing, 3 
letters were signed by 32 organizations and individuals. We treated 
these as 3 individual comments of support. Issues and concerns raised 
by the commenters, and our responses to each are summarized below:
    Issue 1: Some commenters believed that, due to the few remaining 
populations of Salt Creek tiger beetles and the extensive habitat loss, 
immediate protection under the Act is necessary. In addition, a number 
of commenters expressed the need for the Service to also designate 
critical habitat.
    Our Response: We determined that emergency listing was not 
necessary for this subspecies. However, we believe listing is 
warranted. Additionally, we have pursued numerous steps to protect the 
beetle prior to listing. These actions are discussed below. Regarding 
the designation of critical habitat for the Salt Creek tiger beetle, we 
believe critical habitat is both prudent and determinable. However, 
because of the critically imperiled status of Salt Creek tiger beetle, 
limited financial and personnel resources available to work on this 
taxon, and the Service's belief that listing confers greater protection 
on a species than does critical habitat, we have assigned a higher 
priority to promptly publishing the final rule for Salt Creek tiger 
beetle than to proposing and designating critical habitat, as allowed 
pursuant to section 4(b)(6)(C)(i). Funds have been budgeted for 
identification of critical habitat and work on a proposed designation 
is underway. We plan to publish a proposed rule to designate critical 
habitat for Salt Creek tiger beetle in the near future.
    Issue 2: One commenter provided a photograph of a tiger beetle 
along the Missouri River at Ponca State Park in Dixon County, Nebraska, 
and asserted that ``Salt Creek tiger beetles'' were common in the area.
    Our Response: A tiger beetle expert at the University of Nebraska-
Lincoln identified the tiger beetle in the photograph as Cicindela 
formosa, which is not the Salt Creek tiger beetle.
    Issue 3: Several commenters feared the potential effects that 
listing the Salt Creek tiger beetle could have on their use of private 
lands.
    Our Response: On non-Federal property, if Salt Creek tiger beetles 
are not present and activities on the property do not result in take, 
the Act's section 9 prohibitions on take would not come into play. If 
Salt Creek tiger beetles are present on non-Federal property, but 
activities on the property would not result in take, section 9 
prohibitions also would not come into play. If Salt Creek tiger beetles 
are present on non-Federal properties and activities on the property 
are likely to result in take, an incidental take permit may be 
available under section 10(a)(1)(B). As noted elsewhere in this rule, 
critical habitat has not been designated for this species. Once 
designated, additional regulations will regulate adverse modification 
of occupied and unoccupied critical habitat. The Service will provide 
technical assistance to landowner(s) and operator(s) to help them 
avoid, minimize, or mitigate any adverse impacts to the Salt Creek 
tiger beetle and its habitat.
    Proposed activities authorized, funded, or carried out by a Federal 
agency are subject to the consultation requirements prescribed in 
section 7 of the Act. Circumstances under which a proposed Federal 
action or Federal nexus may affect the Salt Creek tiger beetle will be 
handled through consultation with the involved Federal agency and 
applicant(s), as necessary, on a case-by-case basis, in accordance with 
section 7 of the Act.
    Issue 4: Concerns were raised that listing the Salt Creek tiger 
beetle under the Act would have adverse economic and social effects on 
the City of Lincoln and Lancaster County by limiting residential, 
commercial, and industrial developments and agricultural use of lands. 
These commenters requested that the Service consider and analyze the 
possible socioeconomic impacts of the listing action.
    Our Response: Under section 4(b)(1)(A) of the Act, we must base a 
listing decision solely on the basis of the best scientific and 
commercial data available. The legislative history of this provision 
clearly states the intent of Congress to ``ensure'' that listing 
decisions are ``based solely on biological criteria and to prevent non-
biological criteria from effecting such decisions'' (H. Rept. 97-835). 
The Conference Report on the 1982 amendments to the ESA notes that 
economic considerations have no relevance to determinations regarding 
the status of species.

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Economic considerations will be taken into full account when 
designating critical habitat, as required by the Act.
    Issue 5: A few commenters noted that the Salt Creek tiger beetle is 
insignificant to mankind and that insects should not be protected under 
the Act.
    Our Response: The Act recognizes the importance of all species to 
properly functioning ecosystems and requires us to protect species in 
danger of extinction and the ecosystems on which they depend. Section 
3(8) of the Act defines ``the term `fish or wildlife' (as) * * * any 
member of the animal kingdom, including without limitation any mammal, 
fish, bird (including any migratory, nonmigratory, or endangered bird 
for which protection is also afforded by treaty or other international 
agreement), amphibian, reptile, mollusk, crustacean, arthropod or other 
invertebrate, and includes any part, product, egg, or offspring 
thereof, or the dead body or parts thereof.'' Based on the best 
available scientific information, we have determined that the Salt 
Creek tiger beetle is in danger of extinction and warrants protection 
as an endangered species.
    Issue 6: One commenter referenced ``Tiger Beetles: The Evolution, 
Ecology, and Diversity of Cicindelas'' (Pearson and Vogler 2001) and 
concluded that: (1) There is nothing unique about the Salt Creek tiger 
beetle, including its biology; (2) there are many other species of 
tiger beetles; and (3) other tiger beetle species have gone extinct 
without any human-related causes.
    Our Response: (1) As noted above, Busby (2003) examined populations 
of Cicindela nevadica in the central Great Plains and confirmed that C. 
n. lincolniana is distinctive from other populations of C. nevadica in 
the central Great Plains. (2) We do not dispute this claim. As noted 
above, 85 species and more than 200 subspecies of tiger beetles in the 
genus Cicindela are known from the United States (Boyd et al. 1982; 
Freitag 1999). (3) The Service does not dispute the assertion that 
other species of tiger beetles have gone extinct without human related 
causes. However, the Act requires the Service to take action to 
conserve endangered and threatened species, and the ecosystems on which 
they depend, regardless of the cause. The Salt Creek tiger beetle faces 
an imminent risk of extinction.
    Coincidentally, Dr. David L. Pearson, co-author of ``Tiger 
Beetles,'' was asked to provide a peer review of the proposed rule. In 
his review, he stated, ``The present proposal for the Salt Creek tiger 
beetle is by far the most detailed study of potentially threatened or 
endangered tiger beetles I have seen. The population levels, local 
extinction, and robust data on surviving remnant colonies are 
scientifically sound and reliable. There is little doubt in my mind 
reading this document that the Salt Creek tiger beetle will most likely 
go extinct in a relatively short time if no action is taken.''
    Issue 7: Several commenters dispute the Service's claim that cattle 
grazing is a threat to the Salt Creek tiger beetle and its habitat.
    Our Response: Landowners who employ sound grazing management 
practices, including watering sources, generally do not adversely 
impact Salt Creek tiger beetles. However, uncontrolled congregation of 
cattle in areas where Salt Creek tiger beetle larvae exist can result 
in the trampling of both larvae and their burrows. In addition, areas 
that are overgrazed are susceptible to both rain and wind erosion, 
which can result in sediment covering Salt Creek tiger beetle burrows. 
Further, erosion of sediment into Salt Creek tiger beetle habitat from 
overgrazed areas can change the topographic elevation of the habitat 
and render it unsuitable.
    Issue 8: One commenter objected to the use of the term ``applied 
annually'' in the pesticides portion of Factor E in the Summary of 
Factors Affecting the Species section below.
    Our Response: We have modified the sentence and eliminated the word 
``annually.''
    Issue 9: Several commenters expressed their view that agriculture 
is more environmentally friendly today than it traditionally was in the 
past. Some stated that they rarely use pesticides, especially 
insecticides. They also mentioned the use of crop rotation between 
soybeans, grain sorghum, and corn to help manage pest problems on a 
yearly basis. Additionally, they referred to the current existence of 
buffer strips along Little Salt Creek that serve to ``handle'' any 
contamination problems. Another commenter stated that agriculture and 
croplands in the watershed have little effect on Salt Creek tiger 
beetle survival since ``insecticide use is very limited and controlled 
and water conservation structures continue to be installed.''
    Our Response: We are pleased to hear about instances where farmers 
minimize the use of pesticides. However, this does not fully address 
our concern with pesticides, especially insecticides, and their 
potential impacts to Salt Creek tiger beetles. As long as there are 
registered pesticides licensed for use on field crops (including 
soybeans, grain sorghum, and corn), there will be a potential for 
pesticide use in areas where Salt Creek tiger beetles are found. 
Pesticides also are used for purposes other than controlling pests in 
field crops. A primary example is mosquito control, particularly due to 
the presence of West Nile Virus in Nebraska. Buffer strips and other 
water control structures provide some level of protection from this 
factor. Farmers who do not utilize pesticides, or who use ground 
applicators and buffer strips, or other considerations for the Salt 
Creek tiger beetle, are not likely to ``take'' tiger beetles, and so 
are not likely to be impacted by the listing.
    Issue 10: One commenter referred to a water study that the Nebraska 
Department of Environmental Quality (NDEQ) conducted in Little Salt 
Creek from 1977 to 1994. The commenter stated that ``the study 
confirmed that no pesticides of concern were found that would [a]ffect 
the Salt Creek tiger beetle according to John Bender of NDEQ.''
    Our Response: The NDEQ study consisted of one sediment sample and 
one water sample, taken at one location and analyzed for a limited 
number of insecticides. More information regarding the Service's 
concerns with insecticides (including, but not limited, to those 
associated with agriculture) is provided in response to Issue 8 above 
and in the pesticides portion of Factor E in the Summary of Factors 
Affecting the Species section below.
    Issue 11: One commenter stated that there are beetles in Africa 
that feed upon corn stocks. This commenter implied that the Salt Creek 
tiger beetle also could become a pest if allowed to increase its 
numbers.
    Our Response: While some species of beetles are known to be 
agricultural pests, no evidence exists to indicate that tiger beetles 
and specifically, Salt Creek tiger beetles, are agricultural pests. As 
mentioned above in the Background section, the Salt Creek tiger beetle 
is a predatory insect that captures small arthropods. They are not 
known to eat corn stocks or other vegetation.
    Issue 12: One commenter indicated that the Salt Creek tiger beetle 
is in danger of extinction because of the natural changes to the 
habitat in Little Salt Creek as opposed to human-induced changes.
    Our Response: The human-induced impacts that have caused the loss 
and degradation of the Salt Creek tiger beetle's habitat in the Salt 
Creek watershed are documented under Factor A in the Summary of Factors 
Affecting the Species section below.
    Issue 13: It was suggested that: (1) Our references cited should be 
listed in the proposed rule; and (2) that a number of the references 
cited in the proposed rule

[[Page 58340]]

had not been peer reviewed and should have been prior to being used in 
the proposed rule.
    Our Response: (1) As noted in the proposed rule, a complete list of 
references cited is available upon request. Accordingly, we provided 
the commenter with a compact disk that contained the list of references 
cited as well as copies of all documents on the list. (2) The Act 
requires us to make listing determinations on the basis of the best 
scientific and commercial data available. Peer review is a 
consideration in determining what constitutes the best data available, 
but not the sole consideration. However, the Service is committed to 
ensuring reliance upon accurate, reliable, and unbiased information. To 
the greatest extent practicable and appropriate, information that we 
rely upon is internally reviewed for quality, including objectivity, 
utility and integrity. Additionally, in accordance with our July 1, 
1994, Interagency Cooperative Policy for Peer Review in Endangered 
Species Act Activities (59 FR 34270), we solicited peer reviews from 
seven experts in the field of entomology who have extensive experience 
with tiger beetles, to help ensure that our listing decision was based 
on scientifically sound data, assumptions, and analyses. Five of these 
experts provided peer reviews. The results of the peer review are 
discussed below in the Peer Review section of this rule.
    Issue 14: It was suggested that historical data are lacking and 
that recent counts are suspect.
    Our Response: We have no reason to believe that the information we 
have used to make our determination is suspect. The commenter did not 
provide specific examples supporting shortcomings in historic records 
or current sampling methods. Peer reviews of this rule support our 
conclusion that based on best scientific and commercial data available, 
the Salt Creek tiger beetle faces imminent extinction unless preventive 
conservation measures are employed to reverse the current trend.
    Issue 15: A few commenters stated that the Salt Creek tiger beetle 
should not be listed until a recovery plan or action plan is developed 
and approved. In addition, there needs to be an ``estimated 
probability'' that the Salt Creek tiger beetle will be saved by the 
recovery/action plan.
    Our Response: Listing the Salt Creek tiger beetle will initiate 
recovery planning. During the Federal recovery planning process, a 
recovery team develops a recovery plan that establishes a framework for 
the conservation of the species. A recovery plan sets objectives and 
priorities, such as habitat restoration or enhancement, development of 
reintroduction protocols, and identification of potential release 
sites. It also assigns responsibilities to achieve those objectives, 
and estimates the associated costs of completion. Due to the countless 
variables involved, estimating the probability of recovery may not be 
possible. That said, the ultimate purpose of the recovery plan is to 
identify the necessary steps needed to conserve and recover the Salt 
Creek tiger beetle.
    Issue 16: One commenter requested an additional 120-day comment 
period based on scientific uncertainty and economic impact of the 
proposed listing action.
    Our Response: For the following reasons we denied an extension of 
the comment period: (1) economic impacts can not be considered in a 
final listing determination; (2) the Service does not believe there is 
any scientific uncertainty regarding the status of this subspecies, nor 
did the commenter provide any substantive information to illuminate 
this claim; and (3) the time constraints of an out-of-court settlement 
agreement required a final determination regarding the proposed listing 
action by September 30, 2005.
    Issue 17: A few commenters said that the State and local 
governments were doing an adequate job of protecting the Salt Creek 
tiger beetle under their existing authorities and that Federal 
protection under the Act was unnecessary.
    Our Response: We acknowledge that the City of Lincoln, Lancaster 
County and the State of Nebraska have been undertaking actions 
beneficial to the Salt Creek tiger beetle. Existing regulatory 
mechanisms that provide protection for the Salt Creek tiger beetle 
include: federally-implemented regulatory mechanisms such as the 
National Environmental Policy Act (NEPA) and section 404 of the Clean 
Water Act (CWA); State-implemented regulatory mechanisms such as the 
Nebraska State Water Quality Standards (as required by section 401 of 
the CWA) and the Nebraska Nongame and Endangered Species Conservation 
Act (NESCA); and local conservation planning efforts such as the 2002 
City of Lincoln and Lancaster County Comprehensive Plan (Comprehensive 
Plan), the Little Salt Creek Valley Planning Cooperative Agreement co-
sponsored by The Nature Conservancy (TNC), NGPC, and the Saline Wetland 
Conservation Partnership (SWCP) (a local conservation plan). However, 
Federal, State, and local laws, regulations, and policies have not been 
sufficient to prevent past and ongoing losses of Salt Creek tiger 
beetle habitat. Federal listing under the Act will provide additional 
protections. This issue is discussed under Factor D in the Summary of 
Factors Affecting the Species section below.
    Also of significance to this issue, the Nebraska Game and Parks 
Commission recently commented on the proposed rule, ``* * * for the 
agencies to ultimately be successful in preventing the extinction of 
this highly endangered species, the Commission believes that it is 
necessary to utilize the regulatory oversight and funding resources 
that can be made available by (Federal) listing the Salt Creek tiger 
beetle as a federal endangered species.''
    Issue 18: The City of Lincoln requested that the Service proceed 
with a final decision on whether to list the Salt Creek tiger beetle to 
eliminate the existing uncertainty, and to allow the City to move 
forward with planning decisions and development proposals.
    Our Response: We understand the City's desire for a decision on 
this matter. In this action, the Service has finalized the proposal to 
list the Salt Creek tiger beetle as endangered under the Act.
    Issue 19: The City of Lincoln identified numerous conservation 
measures and actions it has taken to protect and preserve the saline 
wetlands of eastern Nebraska and the Salt Creek tiger beetle. The City 
expressed conditional support for listing the Salt Creek tiger beetle, 
provided that there would be adequate Federal funding to establish 
science-based habitat needs to guide future growth of the City and 
Lancaster County while protecting the tiger beetle.
    Our Response: We appreciate the efforts of the City of Lincoln and 
Lancaster County to work with us and other government entities, 
organizations, and landowners to protect the Salt Creek tiger beetle 
and its habitat. To date, the Service has provided funds under 
authority of section 6 of the Act to the City and County, to help with 
the purchase of high-priority habitats for the Salt Creek tiger beetle. 
In addition, section 6 funds have been made available to the University 
of Nebraska-Lincoln for research studies. We also have provided 
technical assistance to the City/County Planning Department by 
providing comments and recommendations for authorized or funded 
projects and activities that may impact the Salt Creek tiger beetle and 
its habitat. We look forward to continued work with the City/County and 
their partners in the

[[Page 58341]]

future, to allow for future growth of the City/County while protecting 
the Salt Creek tiger beetle and saline wetlands of eastern Nebraska. 
Although we cannot guarantee Federal funding will be provided in the 
future, we will make every effort to secure it.

Peer Review

    In accordance with our July 1, 1994, Interagency Cooperative Policy 
for Peer Review in Endangered Species Act Activities (59 FR 34270), we 
solicited peer reviews from experts in the field of entomology who have 
extensive experience with tiger beetles. The purpose of such a review 
is to ensure that listing decisions are based on scientifically sound 
data, assumptions, and analyses, including input from appropriate 
experts. We received comments from five expert reviewers; four of the 
five experts have provided the Service with peer reviews on previous 
listing actions involving tiger beetles. Three research professors 
(from Denison University, Granville, Ohio; Arizona State University, 
Tempe, Arizona; and Randolph-Macon College, Ashland, Virginia) provided 
independent peer review. These experts have had direct experience with 
rare and federally listed tiger beetles throughout the United States 
and the world. In addition, two Salt Creek tiger beetle experts--a 
research technologist in entomology (with an M.S. degree) in the 
Entomology Department of the University of Nebraska-Lincoln, and a UNL 
entomology graduate student (who subsequently received an M.S. for his 
work on the Salt Creek tiger beetle)--reviewed the rule, particularly 
in regard to our interpretation of data on the status, trends, habitat 
requirements, and other biological requisites of the Salt Creek tiger 
beetle. The UNL research technologist has more direct field research 
experience on the Salt Creek tiger beetle than anyone, and the graduate 
student has conducted important research on the life history, habitat 
requirement, and captive rearing potential of the beetle. Both have 
published peer-reviewed scientific articles on the Salt Creek tiger 
beetle. Their review of the rule has helped ensure the scientific 
soundness of our interpretations and analyses.
    All five experts strongly supported listing of the Salt Creek tiger 
beetle as endangered, based on the best available scientific 
information. Two experts provided corrections on minor factual issues, 
interpretation of the data, and citations. One reviewer identified that 
the proposed rule lacked information regarding a molecular phylogeny 
study that could be used to indicate the relationship within Cicindela 
nevadica and between other species of tiger beetles. However, his 
comments indicated that the lack of this information does not diminish 
the information presented in the proposed rule and the need to list the 
Salt Creek tiger beetle. The expert further stated that molecular 
phylogenetic studies of the Salt Creek tiger beetle could prove that 
this tiger beetle is a separate species, thus strengthening the 
argument for protection. All of the experts' information has been 
incorporated into this final rule where appropriate.
    We also received comments from entomologists across the United 
States who have conducted research on tiger beetles, including the 
federally threatened Northeastern beach tiger beetle and Puritan tiger 
beetle. These reviewers also supported the listing of the Salt Creek 
tiger beetle under the Act, based on the information in the proposed 
rule.
    In summary, no information was received from scientific experts to 
indicate that the Salt Creek tiger beetle is more widespread or less 
threatened than we had previously determined in the proposed rule. All 
peer reviewers support the endangered listing.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533) and regulations (50 CFR part 
424) promulgated to implement the listing provisions of the Act set 
forth procedures for determining a species or subspecies to be 
endangered or threatened due to one or more of the five factors 
described in section 4(a)(1) of the Act. These factors and their 
application to the Salt Creek tiger beetle are as follows:

A. Present or Threatened Destruction, Modification, or Curtailment of 
Habitat or Range

Background

    As discussed in the proposed rule (70 FR 5101; February 1, 2005), 
the greatest threat to the Salt Creek tiger beetle is habitat 
destruction (Ratcliffe and Spomer 2002). Like many insects, the Salt 
Creek tiger beetle's close association with specific habitats--salt 
barrens and stream edges--leaves it particularly vulnerable to habitat 
destruction and alteration through direct and indirect means (Pyle et 
al. 1981). The saline wetlands of eastern Nebraska, associated saline 
streams, and freshwater wetlands used by the Salt Creek tiger beetle as 
dispersal habitat have undergone extensive degradation and alteration 
for commercial, residential, transportation, and agricultural 
development since the late 1800s, and are the most restricted and 
imperiled natural habitat type in the State (Gersib and Steinauer 
1991).
    In order to understand the complexity and immediacy of threats to 
the Salt Creek tiger beetle, it is necessary to understand when and how 
the destruction and degradation of the beetle's saline wetland and 
associated stream habitats took place. This is discussed at length in 
the proposed rule (70 FR 5101), and we refer the reader to that 
proposal for additional details beyond what is summarized here. The 
saline wetlands and associated streams of eastern Nebraska began to be 
ditched, drained, and filled beginning in the 1800s, (Murphy 1992; Russ 
et al. 2003). From the 1930s to the 1950s, saline wetlands continued to 
be destroyed for the development of Lincoln (Farrar and Gersib 1991), 
and in the 1960s, the construction of Interstate 80 resulted in 
additional filling, dredging, diking, draining, and diversion in the 
heart of the remaining Salt Creek tiger beetle habitat (Farrar and 
Gersib 1991). Commercial and residential developments, along with road 
construction, have resulted in the loss or degradation of the vast 
majority of barren salt flat and saline stream edge habitat for the 
Salt Creek tiger beetle.
    The three remaining Salt Creek tiger beetle populations are being 
surrounded by commercial and residential development (Ratcliffe and 
Spomer 2002). Although the construction of buildings, homes, roads, 
schools, and parking lots is not occurring directly on salt flats and 
saline stream edges, these projects are occurring adjacent to these 
habitats. Such projects have resulted in the creation of impervious 
surfaces (e.g., access roads, parking lots) that do not allow 
precipitation to seep into the ground. Instead, these surfaces create 
frequent, high-volume freshwater runoff flows that enter the saline 
wetlands and associated streams, diluting their salinity and altering 
hydrology. In addition, runoff originating from other nearby, but not 
necessarily adjacent, residential and commercial developments and 
associated roads flows through constructed drainages, storm sewers, and 
tributaries, and contributes to an increase of freshwater inflow into 
saline wetlands and their associated streams.
    Reduced salinity concentrations and increased sedimentation on 
barren salt flats and along saline stream edges have allowed the 
invasion of vegetation such as Typha angustifolia (cattail) and 
Phalaris arundinacea (reed canary

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grass) into habitats used by the Salt Creek tiger beetle. These plants, 
ordinarily unable to tolerate high salinity, are aggressive invaders 
that convert sunny, barren salt flats into habitat that is dominated by 
an herbaceous overstory. Additionally, sedimentation from runoff at 
construction sites allow for fine silts to deposit on flats allowing 
for increased vegetation encroachment. The resulting vegetated habitat 
is unsuitable for use by the Salt Creek tiger beetle. The overstory 
shades out open, sunny areas required by the Salt Creek tiger beetle to 
thermoregulate, forage, and oviposit (M. Fritz, NGPC, pers. comm. 
2001). Increased vegetative encroachment is the primary factor 
attributed to the extirpation of several populations of other Cicindela 
species (Knisley and Hill 1992).
    Reduced salinity concentrations have resulted in other direct 
impacts. Based on field and laboratory studies using Cicindela 
circumpicta and C. togata, two tiger beetle species that are co-
inhabitants with the Salt Creek tiger beetle on salt flats, Hoback et 
al. (2000) found that salt is required for ovipositing. Allgeier et al. 
(2004) concluded that a species-specific preference for salt and soil 
moisture regimes is important to habitat partitioning and reduction in 
competition between the Salt Creek tiger beetle and other tiger 
beetles. Hoback et al. (2000) also discovered that changes in salinity 
and hydrology may alter the abundance of prey and cause the loss of 
suitable larval habitat for saline wetland-dependent species of tiger 
beetles, including the Salt Creek tiger beetle. Once the hydrologic 
regimes of these saline wetlands and associated streams used by the 
Salt Creek tiger beetle are altered by salinity changes (oftern leading 
to vegetation encroachment), stream incisement (which lowers the water 
table), or other impacts such as bank stabilization, restoration and 
recovery of the habitats can be difficult (Langendoen et al. 2000) and 
expensive (see, for example, https://www.environmentaltrust.org/work/
awards.htm).

Past and Present Habitat Quality and Quantity

    A number of studies have attempted to quantify the amount and rate 
of habitat loss for the saline wetlands of eastern Nebraska. All of 
these studies confirm the extensive loss of saline wetlands, but vary 
in terms of their estimates for the total acres lost due to differences 
in data and methods of analysis. These various studies are discussed at 
length in the proposed rule (70 FR 5101). In 1993 and 1994, a team of 
biologists from various Federal and State agencies completed an 
intensive assessment, inventory, and categorization of the saline 
wetlands of eastern Nebraska. This assessment identified 98 sites that 
could be categorized as Category 1 saline wetlands comprising 
approximately 1,346 ha (3,327 ac) (Gilbert and Stutheit 1994). Category 
1 saline wetlands provide saline wetland functions of high value or 
have the potential to provide high value following restoration or 
enhancement (Gilbert and Stutheit 1994). LaGrange (2003) further 
examined the Gilbert and Stutheit (1994) analysis, and divided Category 
1 saline wetlands into three sub-classes: (1) not highly degraded and 
still functioning--totaling 85 ha (210 ac) (6 percent); (2) degraded, 
but still functioning as a saline wetland, and capable of restoration 
to full function--totaling 1,249 ha (3,087 ac) (93 percent); and (3) 
degraded and not functioning as a saline wetland, but restorable to 
full function--totaling 12 ha (30 ac) (1 percent).
    Although it is important to discuss the overall loss of saline 
wetlands, the impact of that loss on the Salt Creek tiger beetle can 
only be fully assessed by considering the loss of barren salt flat and 
saline stream edge habitats that occur within the confines of Category 
1 saline wetlands. We expanded on the analyses completed by LaGrange 
(2003) and Gilbert and Stutheit (1994) to complete such an assessment. 
Using a Geographic Information System (GIS), we did a habitat 
assessment of the remaining barren salt flat and saline stream edge 
habitats present within the remaining Category 1 saline wetlands. Using 
National Hydrography Dataset information (available online at https://
nhd.usgs.gov) and all known locations of Salt Creek tiger beetles, we 
delineated saline stream edge habitat (J. Runge, USFWS, pers. comm. 
2003). Next, we delineated barren salt flat habitat through the use of 
a feature-extraction process that would select areas containing similar 
spectral signatures of known barren salt flats. Finally, we evaluated 
our GIS analysis qualitatively by ground-truthing select polygons 
within the barren salt flat GIS layer.
    Results from our assessment indicate that the total remaining areas 
of barren salt flat and saline stream edge habitat that exist within 
the saline wetlands of the Little Salt Creek and Rock Creek watersheds 
plus the remnant Salt Basin (i.e., Capitol Beach) are approximately 15, 
33, and 1 ha (38, 81, and 3 ac), respectively, for an overall total of 
49 ha (122 ac). In consideration of the analysis completed by LaGrange 
(2003), we then conducted a spatial analysis to determine the amount of 
habitat currently available for the Salt Creek tiger beetle that is not 
highly degraded. The analysis separated coded barren salt flats into 
Category 1 subclasses identified by LaGrange (2003). Our analysis 
revealed that only approximately 6 ha (15 ac) out of the total 49 ha 
(122 ac) of coded salt barrens are not highly degraded. It is these 
remaining 6 ha (15 ac) of not highly degraded barren salt flats and 
saline stream edges that provide habitat for the Salt Creek tiger 
beetle.
    As the quality of saline habitat continues to decline through 
reduction in size, encroachment of herbaceous species, and modification 
to hydrology, so too does the likelihood that the Salt Creek tiger 
beetle can survive and avoid extinction. Most of the habitat delineated 
in our analysis is composed of extremely small habitat complexes (i.e., 
less than 0.04 ha (0.09 ac)) that are unlikely to provide all of the 
necessary life history requirements that the Salt Creek tiger beetle 
needs to survive. Further, these small habitats are in clusters 
resembling mosaics, separated by herbaceous overstory. This spatial 
dispersion precludes the use of these small areas by the Salt Creek 
tiger beetle. In addition, the loss of saline and freshwater wetlands 
further reduces the connectivity between populations. The loss of 
travel corridors eliminates genetic interchange and the ability to 
repopulate after catastrophic events (Murphy et al. 1990; Fahrig and 
Merriam 1994; Ruggerio et al. 1994; Noss et al. 2002). Spomer et al. 
(2004) reported that no Salt Creek tiger beetles were found in these 
small habitats in the 13 years that surveys were conducted. Carter 
(1989), NGPC (1999), Ratcliffe and Spomer (2002), Spomer and Higley 
(1993 and 2001), Spomer et al. (1997), and Allgeier et al. (2003) all 
concluded that the declining number of populations of Salt Creek tiger 
beetles is due to the loss of suitable saline wetland and stream 
habitat.

Urban Development and Road Construction

    Commercial and residential urban development and road construction 
are the greatest threats to the saline wetlands of eastern Nebraska and 
the plant and animal species that depend upon these habitats (Gilbert 
and Stutheit 1994; Ratcliffe and Spomer 2002). Urban expansion of the 
City of Lincoln (Lincoln) and Lancaster County, fueled by growth in the 
human population of both the City and County, has contributed to the 
decline of the saline

[[Page 58343]]

wetlands of eastern Nebraska and associated streams, and the potential 
extinction of endemic taxa that use these areas, such as the Salt Creek 
tiger beetle. This growth and expansion was discussed in detailed in 
the proposed rule (70 FR 5101), and that rule should be consulted for 
more specifics. The accelerated population growth rate of the region 
has become particularly evident in the last year, as illustrated by 
urban and infrastructure developments (discussed below) that threaten 
the continued existence of the Salt Creek tiger beetle and its limited 
remaining habitat.
    All three extant populations of Salt Creek tiger beetles may be 
threatened with extirpation as a result of expansion of urban 
development and road construction in Lincoln and Lancaster County. A 
review of 1989 and 2002 aerial photographs revealed that over 50 
percent of the area surrounding the Little Salt Creek--Roper population 
(a 1,300-ha (3,200-ac) area bounded by Interstate 80 to the North, Salt 
Creek to the South, North 27th Street to the West, and Highway 77 to 
the East) has been developed within the last 5 years. The 2005 
population survey results for this population were the lowest since 
monitoring began in 1991, with significant declines observed in each of 
the last three years. We reviewed the Comprehensive Plan and found that 
an additional 30 to 40 percent of the area surrounding the Little Salt 
Creek--Roper population has been planned for residential and commercial 
development over the next 25 years. However, given the current rate of 
growth and development surrounding this population, this additional 
area will likely be developed more quickly. In some cases, the local 
municipal development permits for the expansion have already been 
acquired (including some floodplain permits from Lincoln) (R. Harms, 
pers. obs. 2002 and 2003).
    Development is currently underway in areas adjacent to the 
remaining segments of habitat for all three Salt Creek tiger beetle 
populations. These developments have already changed the drainage 
patterns in some areas, resulting in the introduction of excess 
freshwater, sediment, and contaminated urban runoff to saline habitats 
occupied by the Salt Creek tiger beetle. There also are planned highway 
projects which could adversely impact the species due to increases in 
freshwater runoff, vegetative encroachment, risks of toxic spills, and 
alteration of drainage patterns.
    Increased vehicle traffic due to road improvements can increase the 
amount of contaminated runoff flowing into Little Salt Creek from 
vehicles and roadway surfaces. Highway runoff contains a variety of 
chemical constituents, many of which can be harmful to the environment 
when washed from roads by rain and snowmelt into adjacent surface 
waters, groundwater, and ecosystems (Bricker 1999). Contaminated runoff 
can impact the Salt Creek tiger beetle through toxic effects to the 
beetle, its prey base, and its habitat. For the expansion of Interstate 
80, the Federal Highway Administration (FHWA) and Nebraska Department 
of Roads have identified measures that reduce concentrations of 
hazardous and toxic contaminants in highway runoff, and a contingency 
plan for accidental spills that would threaten two populations of Salt 
Creek tiger beetles (FHWA 2003). However, other planned non-Federal 
road and street projects that will be constructed after the Interstate 
80 expansion do not currently address impacts to Salt Creek tiger 
beetle populations from road runoff.

Agriculture

    Agricultural practices in the area also may threaten the limited 
Salt Creek tiger beetle habitat, especially for the Upper Little Salt 
Creek--North and Little Salt Creek--Arbor Lake populations. Livestock 
over-grazing can destroy or substantially degrade habitats for adult 
and larval forms of the Salt Creek tiger beetle through trampling, 
which can destroy Salt Creek tiger beetle larvae burrows and the larvae 
that inhabit them (Spomer and Higley 2001). Cattle grazing also can 
compact soil and modify soil hydrology, gradually drying out a site and 
making it unsuitable for adults and larvae (which prefer moist, muddy 
sites with encrusted salt on soil surfaces). Further, erosion of 
sediment into Salt Creek tiger beetle habitat from overgrazed areas can 
change the topographic elevation of the habitat and render it 
unsuitable. The Upper Little Salt Creek--North population occurs along 
a segment of Little Salt Creek that flows through a pasture, and one of 
these population survey sites may have been negatively impacted by 
cattle grazing (Spomer and Higley 2001; Spomer et al. 2004a). After 
cattle grazing was halted at this site in 2004, the habitat improved 
and observed population numbers increased (Spomer et al. 1997, 1999, 
2001, 2002, 2004a, 2004b; Allgeier et al. 2003; S. Spomer, UNL, pers. 
comm. 2005).
    Cultivation also poses a threat to the largest remaining population 
of Salt Creek tiger beetles, the Little Salt Creek--Arbor Lake 
population. Cultivation can increase sediment erosion that can cover 
larval burrows as well as change soil salinity and encourage vegetative 
encroachment. Such areas may no longer be suitable for ovipositing, 
larval, or foraging habitat. When an area of larval habitat becomes 
degraded and then disappears, so does the species that it supports 
(Dunn 1998). The data now support this assertion. After one such site 
adjacent to a cultivated field was plowed in the fall/winter of 2002/
2003, the habitat be