# Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Nine Bexar County, Texas, Invertebrates

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2011-3038

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** February 22, 2011
- **Citation:** 76 FR 9872

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R2-ES-2010-0091; MO 92210-0-009]
RIN 1018-AX11
Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Nine Bexar County, Texas, Invertebrates

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), propose to revise critical habitat designation for the
Rhadine exilis
(ground beetle, no common name);
Rhadine infernalis
(ground beetle, no common name); Helotes mold beetle (
Batrisodes venyivi
); Cokendolpher Cave harvestman (
Texella cokendolpheri
); Robber Baron Cave meshweaver (
Cicurina baronia
); Madla Cave meshweaver (
Cicurina madla
); and Braken Bat Cave meshweaver (
Cicurina venii
) under the Endangered Species Act of 1973, as amended (Act). We also propose to designate critical habitat for the Government Canyon Bat Cave meshweaver (
Cicurina vespera
) and Government Canyon Bat Cave spider (
Neoleptoneta microps
). These species are collectively known as the nine Bexar County invertebrates. In total, we are proposing approximately 6,906 acres (ac) (2,795 hectares (ha)) as critical habitat for these invertebrates. The proposed critical habitat is located in Bexar County, Texas.

DATES:

We will consider comments received or postmarked on or before April 25, 2011. We must receive requests for public hearings, in writing, at the address shown in the
FOR FURTHER INFORMATION CONTACT
section by April 8, 2011.

ADDRESSES:

You may submit comments by one of the following methods:

•
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the instructions for submitting comments on Docket No. FWS-R2-ES-2010-0091.

•
U.S. mail or hand-delivery:
Public Comments Processing,
Attn:
Docket No. FWS-R2-ES-2010-0091; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203.

We will not accept e-mail or faxes. We will post all comments on
http://www.regulations.gov.
This generally means that we will post any personal information you provide us (
see
the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT:

Adam Zerrenner, Field Supervisor, U.S. Fish and Wildlife Service, Austin Ecological Services Field Office, 10711 Burnet Road, Suite 200, Austin, TX 78758; by telephone at 512-490-0057 x248; or by facsimile at 512-490-0974. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

This document consists of: (1) A proposed rule to revise designated critical habitat for the
Rhadine exilis
(ground beetle, no common name);
Rhadine infernalis
(ground beetle, no common name); Helotes mold beetle (
Batrisodes venyivi
); Cokendolpher Cave harvestman (
Texella cokendolpheri
); Robber Baron Cave meshweaver (
Cicurina baronia
); Madla Cave meshweaver (
Cicurina madla
); and Braken Bat Cave meshweaver (
Cicurina venii
); and (2) A proposed rule to designate critical habitat for Government Canyon Bat Cave meshweaver (
Cicurina vespera
) and Government Canyon Bat Cave spider (
Neoleptoneta microps
).

We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or information from other concerned government agencies, the scientific community, industry, or other interested parties concerning this proposed rule. We particularly seek comments concerning:

(1) The reasons why we should or should not designate habitat as “critical habitat” under section 4 of the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531
et seq.
) including whether there are threats to the species from human activity, the degree of which can be expected to increase due to the designation, and whether that increase in threat outweighs the benefit of designation such that the designation of critical habitat may not be prudent.

(2) Specific information on:

• The amount and distribution of any of the nine Bexar County invertebrates' habitat;

• What areas occupied at the time of listing and that contain features essential to the conservation of the species should be included in the designation and why;

• Special management considerations or protections that the features essential to the conservation of the nine Bexar County invertebrates identified in this proposal may require, including managing for the potential effects of climate change;

• What areas not occupied at the time of listing are essential for the conservation of the species and why; and

• Site-specific information on subsurface geologic barriers to movement of the species or lack thereof.

• The taxonomy and status of the ground beetle previously identified as
Rhadine exilis
in Black Cat Cave (proposed Unit 13) and the value of the cave and unit for conservation of the species.

(3) Land use designations and current or planned activities in the subject areas and their possible impacts on proposed critical habitat.

(4) Any probable economic, national security, or other relevant impacts of designating any area that may be included in the final designation. We are particularly interested in any impacts on small entities or families, and the benefits of including or excluding areas that exhibit these impacts.

(5) Information on whether the benefit of an exclusion of any particular area outweighs the benefit of inclusion under section 4(b)(2) of the Act, in particular for those management plans covering specified lands used as mitigation under the La Cantera Habitat Conservation Plan (HCP) and lands on which impacts to the species have been authorized under that HCP. Copies of the La Cantera HCP are available from the Austin Ecological Services Field Office (
see

FOR FURTHER INFORMATION CONTACT
).

(6) Information on the projected and reasonably likely impacts of climate change on any of the nine Bexar County invertebrates and the critical habitat areas we are proposing.

(7) Information related to our 90-day finding on the July 8, 2010, petition to remove critical habitat Unit 13 from designation (
see Previous Federal Actions
below).

(8) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

You may submit your comments and materials concerning this proposed rule by one of the methods listed in the
ADDRESSES
section. We will not accept

comments sent by e-mail or fax or to an address not listed in the
ADDRESSES
section. We will post your entire comment—including your personal identifying information—on
http://www.regulations.gov.
You may request at the top of your document that we withhold personal information such as your street address, phone number, or e-mail address from public review. However, we cannot guarantee that we will be able to do so.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on
http://www.regulations.gov,
or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Austin Ecological Services Field Office (
see

FOR FURTHER INFORMATION CONTACT
).

Background

It is our intent to discuss only those topics directly relevant to the designation and revised designation of critical habitat in this proposed rule. For more information on the
Rhadine exilis
(ground beetle, no common name),
Rhadine infernalis
(ground beetle, no common name), Helotes mold beetle, Cokendolpher Cave harvestman, Robber Baron Cave meshweaver, Madla Cave meshweaver, Braken Bat Cave meshweaver, Government Canyon Bat Cave meshweaver, and Government Canyon Bat Cave spider, refer to the final listing rule published in the
Federal Register
on December 26, 2000 (65 FR 81419), the proposed critical habitat designation published August 27, 2002 (67 FR 55063), and the final critical habitat designation published April 8, 2003 (68 FR 17155).

The nine species for which we are proposing to designate critical habitat or to revise critical habitat are collectively known as the nine Bexar County invertebrates, and they inhabit caves or other features known as “karst.” The term karst refers to a type of terrain that is formed by the slow dissolution of calcium carbonate from limestone bedrock by mildly acidic groundwater. This process creates numerous cave openings, cracks, fissures, fractures, and sinkholes, and the bedrock resembles Swiss cheese. All of these species are subterranean-dwelling, non-aquatic species of local distribution in north and northwest Bexar County, Texas. They spend their entire lives underground, but surface features are very important as they provide links to drainage into the caves. The following information relates to the designation for all nine species.

Individuals comprising the nine Bexar County invertebrates are small, ranging in length from 0.04 inch (in) (1 millimeter (mm)) to 0.4 in (1 centimeter (cm)). They are eyeless, or essentially eyeless, and most lack pigment or coloration. Adaptations to cave life may include adjustments to the low quantities of food, including low metabolism; long legs for efficient movement; and loss of eyes, possibly as an energy-saving trade-off (Howarth 1983, pp. 374-376). These invertebrates may be able to survive from months to years existing on little or no food (Howarth 1983, p. 375). Average life spans of the listed Bexar County invertebrates in central Texas are unknown, but are likely multiple years for some species (
Cicurina
spp.), based on observations of juveniles kept in captivity (Veni and Associates 1999, p. 165). Reproductive rates of troglobites (small, cave-dwelling animals that have adapted to their dark surroundings), such as these nine invertebrates, are typically very low (Poulson and White 1969, p. 977; Howarth 1983, p. 375).

Based on surveys conducted by Krejca and Weckerly (2007, pp. 286-288), Culver (1986, p. 429), Elliott (1994a, p. 15), and Hopper (2000, p. 459), population sizes of troglobitic invertebrates in humanly-accessible karst features are typically low, with most species known from only a few specimens (Culver
et al.
2000, p. 2350). While very little is known about the ecology of the nine Bexar County invertebrates, they are known to be top predators in their ecosystem (Service 2008, p. 1.4-5) and are dependent on the stability of their prey base that make up the lower trophic levels of the karst ecosystem (Taylor
et al.
2004, p. 28).

Because sunlight is absent or only present in extremely low levels in caves, most karst ecosystems depend on nutrients derived from the surface (organic material brought in by animals, washed in, or deposited through root masses), or imported through the feces, eggs, and carcasses of trogloxenes (species that regularly inhabit caves for refuge, but return to the surface to feed) and troglophiles (species that may complete their life cycle in the cave, but may also be found on the surface) (Barr 1968, pp. 47-48; Poulson and White 1969, pp. 971-972; Howarth 1983, pp. 376-377; Culver 1986, p. 429). Primary sources of nutrients include leaf litter, cave crickets (
Ceuthophilus
spp.), small mammals, and other vertebrates that defecate or die in the cave. While the life habits of the nine invertebrates are not well known, the species probably prey on the eggs, larvae, or adults of other cave invertebrates, such as cave crickets (Mitchell 1971b, p. 250).

Subsurface Environment

The nine Bexar County invertebrates require stable temperatures and constant, high humidity (Barr 1968, p. 47; Mitchell 1971b, p. 250). They have lost the adaptations needed to prevent desiccation in drier habitats (Howarth 1983, p. 368) and the ability to detect or cope with more extreme temperatures (Mitchell 1971a, pp. 300-301). Temperatures in caves are typically the average annual surface temperature with little variation (Howarth 1983, p. 373; Dunlap 1995, p. 76). Relative humidity is typically near 100 percent in caves that support troglobitic invertebrates (Elliott and Reddell 1989, p. 6; Zara 2010, pp. 9-10).

Microhabitat is an important component of features occupied by the nine Bexar County karst invertebrates and has been quantified for three of the listed species that occur on Camp Bullis,
R. exilis, R. infernalis,
and Madla Cave meshweaver (Zara and Veni 2009, pp. 499-505). In observations made in 13 caves,
R. exilis
was seldom found near an entrance (11 out of 147 instances), occasionally found further from the cave entrance in the twilight zone (typified by very little light and more stable humidity and temperatures than the entrance area) (44 out of 147 instances), and more often found deeper in the caves' dark zones (typified by total darkness, stable humidity and temperature) (91 out of 147 instances). The recorded microhabitats (53 instances) occupied by
R. exilis
were varied, with about 66 percent of them on top of the substrate and 34 percent under rocks or on the undersides of rocks or other materials (Zara and Veni 2009, pp. 497, 503).

From measurements made in three caves,
R. infernalis
was found in the entrance (6 out of 23 instances) and twilight zone (10 out of 23 instances) more often that the dark zone (7 out of 23 instances). The species was found under rocks 85 percent of the time (Zara and Veni 2009, pp. 504-505).

From 75 observations made in 2 caves, Madla Cave meshweavers were found 3 times in the twilight and 72 times in the dark. The species was always found among loose rocks or mud balls. In 117 of the 135 instances where location in respect to substrate was recorded, they were underneath or on the underside of rocks. The other times they were on top of rocks (Zara and Veni 2009, pp. 506-512).

During temperature extremes, the nine Bexar County invertebrates may retreat into small, human-inaccessible,

interstitial spaces (mesocaverns), where the physical environment is more conducive to their humidity and temperature preferences (Howarth 1983, p. 372). These species may spend the majority of their time in interstitial spaces, only leaving them to forage in the larger cave passages (Howarth 1987, p. 377). Krejca and Weckerly (2007, p. 287) recommended 14 surveys to determine the presence of
R. exilis
(one of the nine Bexar County invertebrates) in a cave. Krejca and Weckerly (2007, pp. 287-288) hypothesized that when the species are not detected during surveys the invertebrates are in mesocaverns. Therefore, the mesocaverns should be considered a priority for conservation (Krejca and Weckerly 2007, pp. 287-288).

Connectivity of mesocaverns with larger features is needed to maintain gene flow through karst habitat, serve as a conduit for recolonization of features in the future if current habitat becomes unsuitable, provide refuge during times of extreme temperatures and low humidity, and allow for adaptive management of the species as new information becomes available. The Draft Bexar County Invertebrates Recovery Plan recommended good connectivity with mesocaverns for population dynamics of troglobites as a goal for maintaining a healthy karst ecosystem (Service 2008, p. B-1), but did not specify the area needed, because so little is known about the life-history requirements of these invertebrates.

The extent to which the species use mesocaverns between or around caves is not fully known. White (2006, pp. 76-78) studied the distribution of Bexar County karst invertebrates in detail and found that Hilger Hole, Eagle's Nest, Root Canal, and several other caves within and adjacent to Camp Bullis likely functioned as a single habitat patch, and the species had common genetic signatures between caves. The farthest distance between the entrances of these caves is about 1.5 miles (mi) (2.4 kilometers (km)). However, the area around Camp Bullis is different from many of the other Bexar County caves. All of the Camp Bullis area caves were formed within the damage zone of a fault where interconnected mesocaverns and entrance-less caves occur. Because the area is a faults zone, there are long distances of connectivity between mesocaverns. In another part of Bexar County, two caves (Robber's Cave and Hills and Dales Pit) have entrances about 0.3 mi (0.5 km) apart, have high similarity (although not identical) genetics of Madla Cave meshweavers (White 2006, pp. 97-99), and have mesocaverns that are connected (White, SWCA, pers. comm., 2010). Many of the caves where the nine Bexar County invertebrates occur are interconnected with mesocaverns, and some caves have no entrances.

The northern portion of Bexar County is located on the Edwards Plateau, a broad, flat expanse of Cretaceous carbonate rock that ranges in elevation from 1,100 feet (ft) (335 meters (m)) to 1,900 ft (580 m) (Veni 1988, p. 11; Soil Conservation Service 1966, p. 1). This portion of the Edwards Plateau is dissected by numerous small streams. To the southeast of the Edwards Plateau lies the Balcones Fault Zone, a 16-mi (25-km) wide fault zone that extends from the northeast corner of the County to the western County line. The many streams and karst features of this zone recharge the Edwards Aquifer.

The principal cave-containing rock units of the Edwards Plateau are the upper Glen Rose Formation, Edwards Limestone, Austin Chalk, and Pecan Gap Chalk (Veni 1988, p. 24). The Edwards Limestone accounts for one-third of the cavernous rock in Bexar County, and contains 60 percent of the caves. The Austin Chalk outcrop is second to the Edwards in total number of caves. In Bexar County, the outcrop of the upper member of the Glen Rose Formation accounts for approximately one-third of the cavernous rock, but only 12.5 percent of Bexar County caves (Veni 1988, p. 15). In Bexar County, the Pecan Gap Chalk, while generally not cavernous, has a greater than expected density of caves and passages (Veni 1988, p. 24).

Veni (1994, pp. 68-76) delineated six karst areas (karst fauna regions (KFRs)) within Bexar County: Stone Oak, UTSA (University of Texas at San Antonio), Helotes, Government Canyon, Culebra Anticline, and Alamo Heights (Figure 1). These KFRs are bounded by geological or geographical features that may represent obstructions to the movement (on a geologic time scale) of troglobites, which has resulted in the present-day distribution of endemic (restricted to a given region) karst invertebrates in the Bexar County area. The basis for these divisions is the lack of continuity between caves that may form complete barriers or significant restrictions to migration of troglobites over modern or geologic time scales. These discontinuities are defined based on characteristics that affect cave development combined with the geologic history of the area.

BILLING CODE 4310-55-P

Figure 1. Karst Fauna Regions and Karst Zones in Bexar County, Texas.

EP22FE11.000

BILLING CODE 4310-55-C

The KFRs were analyzed using the current range of 19 troglobitic species, including the 9 Bexar County invertebrates (Veni 1994, pp. 72-73). The KFRs are important because they are used to establish recovery criteria for individual species in the Draft Bexar County Karst Invertebrate Recovery Plan. To meet those criteria, specified numbers of preserves of a given quality

must be protected within each KFR in which they occur.

Also, the six KFRs were delineated by Veni (2003, pp. 10-18) into five zones that reflect the likelihood of finding a karst feature that will provide habitat for the endangered invertebrates, based on geology, distribution of known caves, distribution of cave fauna, and primary factors that determine the presence, size, shape, and extent of caves with respect to cave development. As described by Veni (2003, pp. 10-18), these five zones are defined as:

Zone 1:
Areas known to contain one or more of the nine Bexar County invertebrates (areas where species are present).

Zone 2:
Areas having a high probability of suitable habitat for the invertebrates (areas that may contain one or more invertebrates, but have not been fully surveyed).

Zone 3:
Areas that probably do not contain the invertebrates (because there is very little suitable karst habitat).

Zone 4:
Areas that require further research, but are generally equivalent to Zone 3, although they may include sections that could be classified as Zone 2 or 5 (areas where less is known about the karst structure than with Zone 3).

Zone 5:
Areas that do not contain the Bexar County invertebrates (areas with units of rock that do not contain karst habitat).

Surface Environment

Animal Community

Cave Crickets

Cave crickets are a critical source of nutrient input for karst ecosystems (Barr 1968, p. 48; Reddell 1993, p. 2). Cave crickets in the genus
Ceuthophilus
occur in most caves in Texas (Reddell 1966, pp. 32-34). Sensitive to temperature extremes and dry environments, cave crickets forage on the surface at night and roost underground during the day. Taylor
et al.
(2005, p. 103) found that cave crickets lay their eggs in the cave, providing food for a variety of karst species (Mitchell 1971b, p. 250). Some karst species also feed on cave cricket feces (Barr 1968, p. 51; Poulson
et al.
1995, p. 226), and on adults and juveniles directly (Elliott 1994a, p. 16). Cave crickets are scavengers or detritivores (animals that feed on decomposing organic matter), feeding on dead insects, carrion, and some fruits, but not on foliage (Elliott 1994a, p. 16; Taylor
et al.
2004, p. 29).

Elliott (1994a, p. 8) evaluated cave cricket foraging within 164 ft (50 m) of cave entrances. In a more recent study, Taylor
et al.
(2005, p. 97) found that cave crickets foraged much farther, up to 344 ft (105 m) from a cave entrance.

Other Surface Animals

Many central Texas caves with endangered invertebrate species are frequented by mammals, reptiles, and amphibians (Reddell 1967, p. 184). Although there are no studies documenting the role of mammals in central Texas cave ecology, the presence of a large amount of animal materials (such as scat, nesting materials, and dead bodies) indicates they are probably important sources of nutrients. In particular, important sources of nutrients for the cave species may be the fungus, microbes, and other troglophiles and troglobites that grow or feed on animal feces (Elliott 1994b, p. 16; Gounot 1994, p. 204).

For predatory troglobites (such as the nine Bexar County karst invertebrates), invertebrates that accidently occur in the caves may also be an important nutrient source (Hopper 2000, p. 2349). Documented accidental species include snails, earthworms, terrestrial isopods (commonly known as pillbugs or potato bugs), scorpions, spiders, mites, collembola (primitive wingless insects that are commonly known as springtails), thysanura (commonly known as bristletails and silverfish), harvestmen (commonly known as daddy-long-legs), ants, leafhoppers, thrips, beetles, weevils, moths, and flies (Reddell 1965, pp. 146-179; 1966, pp. 27-29; 1999, pp. 40-41).

The imported red fire ant (
Solenopsis invicta
) (fire ant) is an aggressive predator, which has had a devastating and long-lasting impact on native ant populations and other arthropod communities (Vinson and Sorenson 1986, p. 17; Porter and Savignano 1990, p. 2095) and is a threat to the nine Bexar County invertebrates (Elliott 1994b, p. 15; Service 1994, pp. 63-64). Fire ants have been observed building nests both within and near cave entrances as well as foraging in caves, especially during the summer. Shallow caves inhabited by the nine Bexar County invertebrates make them especially vulnerable to invasion by fire ants and other exotic species. Fire ants have been observed preying on several cave species (Elliott 1994b, p. 15). Karst fauna that are most vulnerable to fire ant predation are the eggs, nymphs, and slower-moving adults (James Reddell, Texas Memorial Museum, pers. comm., 2006). The presence of fire ants in and around karst areas could have a drastic detrimental effect on the karst ecosystem through loss of both surface and subsurface species that are critical links in the food chain. Besides direct predation, fire ants threaten listed invertebrates by reducing the nutrient input carried in by cave crickets and other trogloxenes. Because fire ants are voracious, they can out-compete crickets for food resources (Taylor
et al.
2003, pp. 109-110), leading to a reduction in overall productivity in the caves.

The invasion of fire ants is known to be aided by “any disturbance that clears a site of heavy vegetation and disrupts the native ant community” (Porter
et al.
1988, p. 916). Porter
et al.
(1991, p. 873) state that control of fire ants in areas greater than 12 ac (5 ha) may be more effective than in smaller areas, because multiple queen fire ant colonies reproduce primarily by “budding,” where queens and workers branch off from the main colony and form new sister colonies. Maintaining large, undisturbed areas of native vegetation may also help sustain the native ant communities (Porter
et al.
1988, p. 916; 1991, p. 869).

Vegetation Community

Surface vegetation is an important element of the karst habitat for several reasons, including its role in providing nutrients from: (1) Direct flow of plant material into the karst with water; (2) habitat and food sources provided for the animal communities that contribute nutrients to the karst ecosystem (such as cave crickets, small mammals, and other vertebrates); and (3) roots that extend into subsurface areas. Surface vegetation also acts as a buffer for the subsurface environment against drastic changes in temperature and moisture, and serves to filter pollutants before they enter the karst system (Biological Advisory Team 1990, p. 38). In some cases, healthy native plant communities also help control certain exotic species (such as fire ants) (Porter
et al.
1988, p. 916) that may compete with or prey upon the listed species and other species (such as cave crickets) that are important nutrient contributors (Elliott 1994a, pp. 95-96; Lavoie
et al.
2007, p. 126).

Tree roots may provide a major energy source in shallow caves (Howarth 1983, p. 373). Jackson
et al.
(1999, p. 11387) investigated rooting depth in 21 caves on the Edwards Plateau to assess the below-ground vegetational community structure and the functional importance of roots. They observed roots of plateau live oak (
Quercus fusiformis
) penetrating up to 82 ft (25 m) into the interior of one of the caves. The roots of five other tree species, post oak (
Q. sinuata
), cedar elm (
Ulmus crassifolia
), American elm (
U. americana
), sugar hackberry (
Celtis laevigata
), and Ashe juniper (
Juniperus asheii
), penetrated to

below 16 ft (5 m) into caves. These are all common species in the plateau. Most of the caves in Bexar County are less than 20 ft (6 m) deep, so roots have the potential to penetrate many of them.

Karst ecosystems are heavily reliant on surface plant and animal communities to maintain nutrient flows, reduce sedimentation, and resist exotic and invasive species. As the surface around a cave entrance becomes developed, native plant communities are often replaced with impermeable cover or exotic plants from nurseries. The abundance and diversity of native animals may decline due to decreased food and habitat combined with increased competition and predation from urban, exotic, and pet species. As native surface plant and animal communities are destroyed, food and habitat once available to trogloxenes decreases. It is unknown whether exotic species could contribute the same quantity and quality of nutrients to the karst ecosystem.

Woodland-Grassland Community

Because of the various roles played by surface vegetation in maintaining the cave and karst ecosystem, including the nine Bexar County invertebrate species that are part of the ecosystem, we examined the best available scientific information to estimate the surface vegetation needed to support ecosystem processes. The woodland-grassland mosaic community typical of the Edwards Plateau is a patchy environment composed of many different plant species. Van Auken
et al.
(1980, p. 23) studied the woody vegetation of the Edwards and Glen Rose formations in the southern Edwards Plateau in Bexar, Bandera, and Medina Counties. They encountered a total of 24 species of plants on the Edwards or Glen Rose geologic formations, two of the principal, cave-containing rock units of the Edwards Plateau.

To maintain natural vegetation communities over the long term, enough individuals of each plant species must be present for successful reproduction. The number of reproductive individuals necessary to maintain a viable or self-reproducing plant population is influenced by needs for satisfactory germination (Menges 1995, p. 123), genetic variation (Bazzaz 1983, pp. 267-268; Menges 1995, p. 123; Young 1995, pp. 154-155), and pollination (Groom 1998, p. 487; Jennersten 1995, p. 130; Bigger 1999, p. 239). Pavlik (1996, p. 136) stated that long-lived, self-fertilizing, woody plants with high fecundity would be expected to have minimum viable population sizes in the range of 50 to 250 reproductive individuals. Fifty reproductive individuals is a reasonable minimum figure for one of the dominant species of the community, Ashe juniper, based on reproductive profiles (Van Auken
et al.
1979, p. 170; Van Auken
et al.
1980, pp. 30-31; Van Auken
et al.
1981, pp. 1251-1253). This figure would likely be an underestimate for other woody species present in central Texas woodlands, because other woody species are more sensitive to environmental changes and do not meet several of the life-history criteria needed for the lowest minimal viable population size. Although other woody species may require population sizes at the higher end of the range (near 250 individuals) to be viable, as suggested by Pavlik (1996, p. 136), we do not have the data to support that contention. Therefore, on the basis of our review of information available to us, and after soliciting input from a botanist with expertise in the Edwards Plateau (Dr. Kathryn Kennedy, Center for Plant Conservation, pers. comm., 2002), we consider a minimum viable population size for individual plant species composing a typical oak/juniper woodland found in central Texas to be 80 individuals per species. This estimate is based on a habitat type that, as a whole, is fairly mature, and on knowledge that the species are relatively long-lived and reproductively successful.

Based on an analysis of recorded densities, corrected for non-reproductive individuals, we then calculated the area needed to support 80 mature reproductive individuals per species for the 24 species reported by Van Auken
et al.
(1980, p. 23). We determined that the 4 highest area requirements to maintain at least 80 mature individuals were for species that occur at lower densities. These included 198 ac (80 ha) for brasil (
Condalia hookeri
), and approximately 80 ac (32 ha) for each of hoptree (
Ptelea trifoliata
), Mexican buckeye (
Ungnadia speciosa
), and chittamwood (
Bumelia lanuginosa
). Our calculations indicate that the area needed to maintain the seven species with the highest average dominance values, Ashe juniper, Texas live oak, Texas red oak (
Quercus texana
), catclaw acacia (
Acacia greggii
), evergreen sumac (
Rhus virens
), agarita (
Mahonias trifoliata
), and cedar elm (
Ulmus crassifolia
), is approximately 33 ac (13 ha). An area of 33 ac (13 ha) would maintain 80 reproductive individuals for 15 of the 24 species. The area needed to maintain the nine rarest plant species ranges from approximately 49 to 198 ac (20 to 80 ha) with 7 of species in the 65 to 80 ac (26 ha to 32 ha) range.

The Bexar County Invertebrates Draft Recovery Plan used a minimum viable population size of 80 individuals of the top 15 to 20 woodland species and recommended 80 ac (32 ha) of woodland habitat for establishing a high-quality preserve that maintains a diverse community of woody vegetation for at least 100 years (Service 2008, pp. B-9 to B-11).

Most literature found for central Texas native grasslands was descriptive and not quantitative in its treatment of species composition and dispersion. No literature was located that provided grassland species area curves or quantitative species density tables for the central Texas area. Two papers by Lynch (1962, p. 679; 1971, p. 890) examined grassland species on an 8-ac (3.2-ha) tract over time with 123 species and high species turnover. High species turnover can be indicative of a habitat area which is too small; however, pre- and post-drought conditions may also have affected this situation. In a slightly more mesic grassland habitat, Robertson
et al.
(1997, p. 65) found that a 10-ac (4-ha) site captured most of the grassland species diversity (100 species) present, although it does not address population sizes and persistence in isolation, and an increase to a 14-ac (6-ha) tract increased species representation to 140. Another paper on a grassland in a more westerly and drier location in central Texas recorded 157 taxa in a 40-ac (16-ha) enclosure between 1948 and the mid-1970s (Smeins
et al.
1976, pp. 24-25).

The Draft Bexar County Invertebrates Recovery Plan recommends that 10 ac (4 ha) of total grassland area within a woodland-grassland mosaic is needed in the preserves. This figure was derived by adding a 2 ac (0.8 ha) margin to the 8 ac (3 ha) tract (
see
previous paragraph) with typical species diversity based on Lynch's (1962, p. 679; 1971, p. 890) studies to provide additional area that would aid community stability if the high species turnover there was not due to regional drought influences alone.

Edge Effects

To maintain a viable vegetative community, including woodland and grassland species, an undisturbed area is needed to shield the core habitat from impacts associated with edge effects or disturbance from adjacent urban development (Lovejoy
et al.
1986, p. 284; Yahner 1988, pp. 333-334). In this context, edge effects refer to the adverse changes to natural communities (primarily from increases in invasive species and pollutants, and changes in

microclimates) from nearby areas that have been modified for human development.

The changes caused by edge effects can occur rapidly. For example, vegetation 6.6 ft (2 m) from a newly created edge can be altered within days (Lovejoy
et al.
1986, pp. 258-259). Edges may allow invasive plant species to gain a foothold where the native vegetation had previously prevented their spread (Saunders
et al.
1991, p. 23; Kotanen
et al.
1998, p. 669; Suarez
et al.
1998, pp. 2041-2042; Meiners and Steward 1999, p. 261). When plant species composition is altered as a result of an edge effect, changes also occur in the surface animal communities (Lovejoy and Oren 1981, p. 11; Harris 1984, pp. 72, 74; Mader 1984, p. 90; Thompson 1985, pp. 526-527; Lovejoy
et al.
1986, pp. 283-284; Yahner 1988, p. 335; Fajer
et al.
1989, p. 1199; Kindvall and Ahlen 1992, pp. 523, 528; Tscharntke 1992, pp. 534-535; Hanski 1995, p. 204; Lindenmayer and Possingham 1995, p. 236; Bowers
et al.
1996 p. 188; Hill
et al.
1996, p. 726; Kozlov 1996, pp. 99-100, 102; Kuussaari
et al.
1996, pp. 791, 798; Turner 1996, p. 204; Mankin and Warner 1997, pp. 140-142; Burke and Nol 1998, p. 96; Didham 1998, p. 404; Suarez
et al.
1998, p. 2041; Crist and Ahern 1999, p. 687; Kindvall 1999, p. 181). Changes in plant and animal species composition because of edge effects may unnaturally change the nutrient cycling processes required to support cave and karst ecosystem dynamics. To minimize edge effects, the area needed to support a native plant and animal community must have a sufficient perimeter area to protect it.

One recommendation for protecting forested areas from edge effects that are in proximity to clear-cut areas is use of the “three tree height” approach (Harris 1984, p. 110) for estimating the width of the perimeter area needed. We used this general rule to estimate the width of perimeter areas needed to protect the habitat areas. The average height of native mature trees in the Edwards woodland association in Texas ranges from 10 to 30 ft (3 to 9 m) (Van Auken
et al.
1979, p. 177). Applying the “three tree height” general rule, and using the average value of 21.6 ft (6.6 m) for tree height, we estimated that a perimeter width of at least 66 ft (20 m) is needed around a core habitat area to protect the vegetative community from edge effects. Based on this rule, 10 ac (4 ha) is necessary to protect a 79-ac (32-ha) circular core area. We recognize that the “three tree height” approach described by Harris (1984, pp. 110-111) was based on the distance that effects of storm events (“wind-throw”) from a surrounding clear-cut “edge” will penetrate into an old-growth forest stand. Although the effects of edge on woodland/grassland mosaic communities have not been well studied, we believe that the “three trees height” recommendation is the best available peer-reviewed science to protect woodland areas from edge effects (Dr. Kathryn Kennedy, Center for Plant Conservation, pers. comm., 2003).

Animal communities also should be protected from impacts associated with edge effects or disturbance from adjacent urban development. Edges can act as a barrier to dispersal of birds and mammals (Yahner 1988, p. 336; Hansson 1998, p. 55). Invertebrate species are affected by edges. Mader
et al.
(1990, p. 214) found that carabid beetles and lycosid spiders avoided crossing unpaved roads that were even smaller than 9 ft (3 m) wide. Saunders
et al.
(1990, p. 23) suggested that as little as 330 ft (100 m) of agricultural fields may be a complete barrier to dispersal for invertebrates and some species of birds. In general, for animal communities, species need buffers of 164 to 330 ft (50 to 100 m) or greater to ameliorate edge effects (Lovejoy
et al.
1986, p. 263; Wilcove
et al.
1986, pp. 249-250; Laurance 1991, p. 206; Laurance and Yensen 1991, pp. 78-79; Kapos
et al.
1993, p. 425; Andren 1995, p. 237; Reed
et al.
1996, p. 1102; Burke and Nol 1998, p. 96; Didham 1998, p. 397; Suarez
et al.
1998, p. 2047).

Nonnative fire ants are known to be harmful to many species of invertebrates and vertebrates. In coastal southern California, Suarez
et al.
(1998, p. 2041) found that densities of the exotic Argentine ant (
Linepithema humile
), which has similar life-history and ecological requirements to the red imported fire ant (Dr. Richard Patrock, University of Texas at Austin, pers. comm., 2003), are greatest near disturbed areas. Native ant communities tended to be more abundant in native vegetation and less abundant in disturbed areas. Based on the association of the Argentine ant and distance to the nearest edge in urban areas, core areas may only be effective at maintaining natural populations of native ants when there is a buffer area of at least 660 ft (200 m) (Suarez
et al.
1998, pp. 2050, 2052).

We do not have site-specific information on the area needed to maintain populations of animal species, including cave crickets, found in central Texas. Therefore, we are relying on information from other areas. Based on that information, animal communities should be protected by areas of 164 to 330 ft (50 to 100 m) or greater to ameliorate edge effects, and by areas of 660 ft (200 m) to protect against the effects of fire ants. From this data, we determined that a distance of 330 ft (100 m), in addition to the 344-ft (105-m) cave cricket foraging area, would be the minimum needed to protect the cave cricket foraging area from the effects of edge and nonnative species invasions.

Dispersal

The ability of individuals to move between preferred habitat patches is essential for colonization and population viability (Eber and Brandl 1996, p. 621; Fahrig and Merriam 1994, p. 52; Hill
et al.
1996, pp. 725-726; Kattan
et al.
1994, pp. 139, 143; Kindvall 1999, p. 172; Kozlov 1996, pp. 95-96; Kuussaari
et al.
1996, p. 791; Turner 1996, p. 205). Patch shapes allowing connection with the highest number of neighboring patches increase the likelihood that a neighboring patch will be occupied (Fahrig and Merriam 1994, p. 53; Kindvall 1999, p. 172; Kuussaari
et al.
1996, p. 791; Tiebout and Anderson 1997, p. 620). If movement among populations is restricted and a population is isolated, the habitat patch size must be large enough to ensure that the population can survive (Fahrig and Merriam 1994, p. 54).

Summary

The conservation of the endangered Bexar County karst invertebrates depends on a self-sustaining karst ecosystem, surface and subsurface drainage basins to maintain adequate quantity and quality of moisture, and a viable surface animal and plant community for nutrient input and protection of the subsurface from adverse impacts. The area needed to conserve such an ecosystem includes a minimum core area of 100 ac (40 ha) of healthy, native woodland-grassland mosaic comprised of 80 ac (32 ha) of woodland, 10-ac (4-ha) of grassland, and a 10-ac (4-ha) buffer to protect against edge effects. The 100-ac (40-ha) core area should encompass the surface and subsurface drainage basins of the occupied feature, the 344-ft (105-m) cave cricket foraging distance from the entrance to the cave, and a 330-ft (100-m) distance from the cave cricket area to protect against edge effects.

Listed Bexar County Invertebrates' Distribution

By 2000, about 400 caves were known from Bexar County (SWCA 2000). Of the 400 caves, 57 were known to contain 1 or more of the 9 Bexar County invertebrates at the time the species

were listed in 2000 (65 FR 81419; December 26, 2000). Currently, we are aware of 89 caves in Bexar County that contain 1 or more of the 9 Bexar County invertebrates (Table 1).

Table 1—Caves Known To Contain One or More of the Nine Listed Bexar County Karst Invertebrates
[We include subspecies in this table in order to show genetic diversity by cave]

Species (# of caves)
Cave name
Karst fauna

Rhadine exilis
(51)

40 mm Cave *
Stone Oak.

B-52 Cave *

Backhole *

Banzai Mud Dauber Cave *

Black Cat Cave

Blanco Cave

Boneyard Pit *

Bunny Hole *

Constant Sorrow Cave *

Cross the Creek Cave *

Dos Viboras Cave *

Eagle's Nest Cave *

Hairy Tooth Cave

Headquarters Cave *

Hilger Hole *

Hold-Me-Back Cave *

Hornet's Last Laugh Pit

Isocow Cave

Kick Start Cave

MARS Pit *

MARS Shaft *

Pain in the Glass Cave *

Peace Pipe Cave *

Platypus Pit *

Poor Boy Baculum Cave *

Ragin' Cajun Cave

Root Canal Cave *

Root Toupee Cave *

Springtail Crevice

Strange Little Cave *

Up the Creek Cave *

Christmas Cave
Helotes.

Helotes Blowhole

Helotes Hilltop Cave

Logan's Cave

unnamed cave
1/2
mile N. of Helotes

Creek Bank Cave
Government Canyon.

Government Canyon Bat Cave

Lithic Ridge Cave

Pig Cave

San Antonio Ranch Pit

Tight Cave

Hills and Dales Pit
UTSA.

John Wagner Ranch Cave No. 3

Kamikazi Cricket Cave

La Cantera Cave No. 1

La Cantera Cave No. 2

Mastodon Pit

Robber's Cave

Three Fingers Cave

Young Cave No. 1

R. infernalis ewersi
(3)

Flying Buzzworm Cave *
Stone Oak.

Headquarters Cave *

Low Priority Cave *

R. infernalis
new subspecies (9)

Braken Bat Cave
Caracol Creek Coon Cave

Culebra Anticline.

Game Pasture Cave No. 1

Isopit

King Toad Cave

Max and Roberts Cave

Obvious Little Cave

Stevens Ranch Trash Hole Cave

Wurzbach Bat Cave

R. infernalis infernalis
(28)

Bone Pile Cave
10 K Cave.

Government Canyon.

Canyon Ranch Pit

Continental Park Cave

Dancing Rattler Cave

Fat Man's Nightmare Cave

Government Canyon Bat Cave

Hackberry Sink

Lithic Ridge Cave

Pig Cave

San Antonio Ranch Pit

Scenic Overlook Cave

Sure Sink

Surprise Sink

Christmas Cave
Helotes.

Helotes Blowhole

Logan's Cave

Madla's Cave

Madla's Drop Cave

Sir Doug's Cave

Genesis Cave
Stone Oak.

John Wagner Ranch Cave No. 3
UTSA.

Kamikazi Cricket Cave

Mattke Cave

Robber's Cave

Scorpion Cave

Three Fingers Cave

Crownridge Canyon Cave

Helotes mold beetle (8)

San Antonio Ranch Pit
Scenic Overlook Cave.

Government Canyon.

Tight Cave

Christmas Cave
Helotes.

Helotes Hilltop Cave

Unnamed Cave
1/2
mile N of Helotes

Unnamed Cave
1/2
mile NE of Helotes

Unnamed Cave 5 miles NE of Helotes
UTSA.

Cokendolpher Cave harvestman (1)
Robber Baron Cave
Alamo Heights.

Robber Baron Cave meshweaver (2)

Robber Baron Cave meshweaver (2)
OB3

Alamo Heights.

Madla Cave meshweaver (20)
Christmas Cave
Helotes.

Madla's Cave

Madla's Drop Cave

Helotes Blowhole

Helotes Hilltop Cave

Headquarters Cave *
Stone Oak.

Breathless Cave
UTSA.

Feature No. 50

Hills and Dales Pit

John Wagner Ranch Cave No. 3

La Cantera Cave No. 1

Robber's Cave

Unnamed Cave Helotes Area

Fat Man's Nightmare Cave
Government Canyon.

Lithic Ridge Cave

Lost Pothole

Pig Cave

San Antonio Ranch Pit

Scenic Overlook Cave

Surprise Sink

Braken Bat Cave
Braken Bat Cave
Culebra Anticline.

Government Canyon
Government Canyon Bat Cave
Government.

Government Canyon
Government Canyon Bat Cave
Government.

Surprise Sink

* Cave located on Camp Bullis.

Previous Federal Actions

We published a proposed rule to list the nine Bexar County karst invertebrate species as endangered in the
Federal Register
on December 30, 1998 (63 FR 71855). On November 1, 2000, the Center for Biological Diversity filed a complaint against the Service alleging that we exceeded our 1-year obligation to publish a final listing rule and make a determination whether to designate critical habitat for the nine Bexar County karst invertebrates. We published a final listing rule on December 26, 2000 (65 FR 81419). In the final listing rule, we determined that critical habitat designation was prudent. On August 27, 2002, we proposed that 25 units encompassing approximately 9,516 ac (3,857 ha) in Bexar County, Texas, be designated as critical habitat for the 9 karst invertebrates (67 FR 55063). The final critical habitat rule, designating approximately 1,063 ac (431 ha) in 22 units, was published on April 8, 2003 (68 FR 17155).

On July 17, 2007, the Center for Biological Diversity, Citizens Alliance for Smart Expansion, and Aquifer Guardians in Urban Areas provided us with a 60-day notice of intent to sue on the final critical habitat rule. On January 14, 2009, the plaintiffs (
CBD
v.
FWS,
case number 1:09-cv-00031-LY) filed suit in Federal Court (Western District of Texas) alleging that the Service failed to use the best available science and incorrectly made exclusions according to sections 3(5)(A) and 4(b)(2) of the Act. On December 18, 2009, the parties filed a settlement agreement where we agreed to submit a revised proposed critical habitat determination for publication in the
Federal Register
on or before February 7, 2011, and a final revised determination by February 7, 2012. This proposed rule is published in accordance with that agreement.

On July 8, 2010, we received a petition from Capital Foresight Limited Partnership to revise designated critical habitat for
Rhadine exilis
by removing Unit 13. The petitioner alleges that the original specimens collected from Black Cat Cave were never positively identified as
R. exilis,
another species of
Rhadine
with a slender body form similar to
R. exilis
occurs in a cave a short distance from Black Cat Cave that is likely connected by mesocaverns, and that two species of
Rhadine
with similar body forms have never been documented to occur in the same location. In addition, the petitioner asserts that drinking water is leaking into Black Cat Cave and that the habitat has been highly degraded by the Bulverde Road rending the area no longer suitable for conservation of the species. In reference to the petitioner's claims, more information is needed for us to make a determination. Information in our files indicates that a species expert has identified the original specimen collected from Black Cat Cave as
R. exilis
(T. Barr, pers. comm., 2010). At this time, we find that the petitioner presents substantial scientific or commercial information indicating that revising critical habitat for
R. exilis
may be warranted, but more information is needed. Therefore, with the publication of this rule, we are initiating a review to determine if revising critical habitat for
R. exilis
is warranted. For this proposed critical habitat rule, we believe that Unit 13 continues to meet the definition of critical habitat as discussed in the
Criteria Used to Identify Critical Habitat
section below. Thus, Unit 13 continues to be part of this proposed critical habitat rule, but changes may be made in the final rule based upon new information. This document constitutes our 90-day finding on the petitioned action. We request public comment on this finding. We will issue a 12-month finding on the petition in conjunction with the final critical habitat rule for the nine Bexar County invertebrates, which will address whether the petitioned action is warranted, as provided in section 4(b)(3)(B) of the Act.

Critical Habitat

Background

Critical habitat is defined in section 3 of the Act as:

(1) The specific areas within the geographical area occupied by the species, at the time it is listed in accordance with the 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 to use and 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 actions likely to result in the destruction or adverse modification of critical habitat. Section 7(a)(2) 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) would apply, but even in the event of a destruction or adverse modification finding, Federal action agency's and the applicant's obligation is not to restore or recover the species, but to implement reasonable and prudent alternatives to avoid destruction or adverse modification of critical habitat.

For inclusion in a critical habitat designation, the habitat within the geographical area occupied by the species at the time it was listed must contain the physical and biological features essential to the conservation of the species, and 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 (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 it is listed only when we determine that those areas are essential for the conservation of the species and that designation limited to those areas occupied at the time of listing would be inadequate to ensure the conservation of the species.

Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific and commercial data available. Further, our Policy on Information Standards under the Endangered Species Act (published in the
Federal Register
on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), and our associated Information Quality Guidelines, provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific data available. They require our biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat.

When we are determining which areas 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. Climate change will be a particular challenge for biodiversity because the interaction of additional stressors associated with climate change and current stressors may push species beyond their ability to survive (Lovejoy 2005, pp. 325-326). The synergistic implications of climate change and habitat fragmentation are the most threatening facet of climate change for biodiversity (Hannah
et al.
2005, p. 4). Current climate change predictions for terrestrial areas in the Northern Hemisphere indicate warmer air temperatures, more intense precipitation events, and increased summer continental drying (Field
et al.
1999, pp. 1-3; Hayhoe
et al.
2004, p. 12422; Cayan
et al.
2005, p. 6; Intergovernmental Panel on Climate Change (IPCC) 2007, p. 1181). Climate change may lead to increased frequency and duration of severe storms and droughts (Golladay
et al.
2004, p. 504; McLaughlin
et al.
2002, p. 6074; Cook
et al.
2004, p. 1015).

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 we implement under section 7(a)(1) of the Act. Areas that support populations are also subject to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best available 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, HCPs, or other species conservation planning efforts if new information available at the time of 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 at the time of listing to propose as critical habitat, we consider the physical and biological features essential to the conservation of the species that may require special management considerations or protection. 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 specific physical and biological features required for the nine Bexar County invertebrates from studies of these species' habitat, ecology, and life history as described below.

Space for Individual and Population Growth and for Normal Behavior

The nine Bexar County invertebrates are terrestrial troglobites that require underground passages with stable temperatures (Howarth 1983, p. 373; Dunlap 1995, p. 76) and constant, high humidity (Barr 1968, p. 47; Mitchell 1971a, p. 250). In addition to the larger cave passages that are accessible by humans where the species are collected, the species also need mesocaverns (tiny voids that are connected to larger cave passages) (Howarth 1983, p. 371), which

provide additional habitat to sustain viable populations for the species (White 2006, pp. 100-101). During temperature extremes, small mesocavernous spaces connected to caves may have more favorable humidity and temperature levels than the cave (Howarth 1983, p. 371). However, the abundance of food may be less in mesocaverns than in the larger cave passages. Therefore, the nine Bexar County invertebrates may spend the majority of their time in mesocaverns, only leaving during temporary forays into the larger cave passages to forage (Howarth 1987, p. 377). Based on the information above, we identify karst-forming rock containing subterranean spaces (caves and connected mesocaverns) with stable temperatures, high humidities (near saturation), and suitable substrates (spaces between and underneath rocks for foraging and sheltering) to be a physical and biological feature needed by these species.

Food, Water, Air, Light, Minerals, or Other Nutritional or Physiological Requirements

Surface Water

The nine Bexar County invertebrates need clean water that is free of pollutants to maintain stable humidity and temperatures. In order to maintain stable humidity, the amount of clean water varies depending on the size of the drainage basin, caves, and mesocaverns. Water enters the karst ecosystem through surface and subsurface drainage basins. Well-developed pathways, such as cave openings and fractures, rapidly transport water through the karst with little or no purification. Caves are susceptible to pollution from contaminated water entering the ground because karst has little capacity for self-purification. The route that has the greatest potential to carry water-borne contaminants into the karst ecosystem is through the drainage basins that supply water to the ecosystem. Because cave fauna require material washed in through entrances (including humanly inaccessible cracks), and because they require generally high humidity, it is critical to have drainage basins with unpolluted water. The surface drainage basin consists of the cave entrance and other surface input sources, such as neighboring sinkholes and soil percolation. The subsurface or groundwater drainage basin includes mesocaverns, subterranean streams, and sinkholes that have a connection to the surface, even though the groundwater drainage basin is not always observable from the surface. It is also important to note that the surface and subsurface drainage basins do not necessarily overlap. They may be of different size and direction (Veni 2003, pp. 7-8).

In conclusion, we identify clean surface water that flows into the karst features to be a physical and biological feature needed by these species. Sources may include runoff that flows into the caves' entrances or associated features through sinkholes or fractures, and through-ground flows via fractures, conduits, and passages.

Surface Plant and Animal Community

Areas around and over caves occupied by the nine Bexar County invertebrates need healthy surface plant and animal communities (
see
discussion in Background). Surface vegetation provides nutrients that support trogloxene and accidental species and provides nutrients through leaf litter and root masses that grow directly into caves (Howarth 1983, p. 373; Jackson
et al.
1999, p. 11387). Because listed troglobites are at the top of their food chain (Service 2008, p. 4.1-5), habitat changes that affect their food sources (including plants and cave crickets) can affect troglobites (Culver
et al.
2000, p. 395). Surface vegetation also protects the subsurface environment against drastic changes in the temperature and moisture regime. It serves to filter pollutants (to a limited degree) before they enter the karst system and protects against nonnative species invasions (Biological Advisory Team 1990, p. 38). Surface invertebrates provide food for trogloxenes, such as cave crickets, bats, toads, and frogs. Other animals wash or accidentally stumble into caves and are food sources for cave-limited species. A healthy native arthropod community may better stave off fire ants, a threat to the karst ecosystem (Porter
et al.
1988, p. 914).

As discussed in the background section, cave crickets are an important source of nutrient input for karst ecosystems (Barr 1968, p. 48; Reddell 1993, p. 2). The cave crickets forage on the surface at night and roost in the cave during the day. Cave crickets provide food for karst species, which feed on their eggs, young, and feces (Mitchell 1971b, p. 250; Barr 1968, pp. 51-53; Poulson
et al.
1995, p. 26).

Many of the vertebrate species that occasionally use caves bring in a significant amount of energy in the form of scat, nesting material, and carcasses. Natural quantities of all of these components are an important part of a functioning ecosystem. Therefore, based on the information above, we identify a healthy surface community of native plants (juniper-oak woodland) and animals (cave crickets) living in and near the karst feature that provides nutrient input and protects the karst ecosystem from adverse effects (nonnative species invasions, contaminants, and fluctuations in temperature and humidity), as being a necessary biological feature.

Primary Constituent Elements for the Nine Bexar County Invertebrates

Under the Act and its implementing regulations, we are required to identify the physical and biological features essential to the conservation of the nine Bexar County invertebrates in areas occupied at the time of listing, focusing on the features' primary constituent elements (PCEs). We consider primary constituent elements to be the elements of physical and biological features that, when laid out in the appropriate quantity and spatial arrangement to provide for a species' life-history processes, are essential to the conservation of the species.

Based on the above needs and our current knowledge of the life history, biology, and ecology of these species and the habitat requirements for sustaining the essential life-history functions of the species, we have determined that the nine Bexar County invertebrates' PCEs are:

(1) Karst-forming rock containing subterranean spaces (caves and connected mesocaverns) with stable temperatures, high humidities (near saturation), and suitable substrates (for example, spaces between and underneath rocks for foraging and sheltering);

(2) Surface water free of pollutants that flows into the karst features. Sources may include surface runoff that flows directly into the caves' entrances, or water that flows through associated features, such as sinkholes and fractures known to connect to the karst features, or water that flows through the connected subsurface drainage area and subsequently into caves and passages; and

(3) A healthy surface community of native plants (for example, juniper-oak woodland) and animals (for example, cave crickets) living near the karst feature that provides nutrient input and protects the karst ecosystem from adverse effects (for example, from nonnative species invasions, contaminants, and fluctuations in temperature and humidity).

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 contain features that are essential to the conservation of the species and that may require special management considerations or protection. The following information provides discussion of the threats to essential features and the special management considerations and protections needed to alleviate those threats.

The Bexar County human population is projected to increase 13.8 percent from 2010 to 2020, and 45.2 percent by 2050 (San Antonio Planning Department 2005, p. 1). Most of the threats to the PCEs are the result of this continued rapid population growth and associated urbanization. Threats include: Filling and collapsing of caves; alteration of drainage patterns, causing decreased water infiltration and karst drying or increased flooding; removal of native vegetation and replacement with impervious cover and nonnative plants; reducing nutrient input; changes in temperature; decreasing humidity; habitat contamination from human activities in the surface and subsurface drainage basins of caves and in adjacent karst areas; increased human visitation resulting in alteration of the cave habitat and direct mortality of listed species; and infestation by fire ants, a predator and competitor that can cause direct predation on and competition with trogloxenes like cave crickets, ultimately reducing nutrient input into the cave.

Veni (1994, p. 23) estimated in 1991 that about 26 percent of known caves in Bexar County had been destroyed through filling, capping, covering with roads and buildings, or blasting by construction and quarrying operations. Further loss undoubtedly has occurred since that report and will likely continue unless appropriate controls are implemented. Construction and development activities that may not destroy an entrance can still result in collapses of the cave ceiling or other adverse effects on the karst environment. On ranch land or in rural areas, it is not uncommon to use caves as trash dumps (Culver 1986, p. 434; Reddell 1993, p. 2) or to cover the entrances to prevent livestock from falling in (Elliott 2000, pp. 374-375). These activities can be detrimental to the karst ecosystem by causing direct destruction of habitat or altering the natural passage of organisms, water, detritus, and other organic matter into a cave. Quarrying of limestone and road base material is a widespread activity that can remove vegetation and destroy karst habitat. A number of occupied caves in Bexar County have been severely impacted in the past, and an examination of recent aerial photography reveals recent impacts to karst habitat in the vicinity of those areas.

Cave organisms are adapted to live in a narrow range of temperature and humidity. To sustain these conditions, both natural surface and subsurface flow of water and nutrients should be maintained. Decreases in water flow or infiltration can result in excessive drying and may slow decomposition, while increases can cause flooding that drowns air-breathing species and carries away available nutrients. Alterations to surface topography, including decreasing or increasing soil depth or adding nonnative fill, can change the nutrient flow into the cave and affect the cave community (Howarth 1983, p. 381). Changes in the amount of impermeable cover, collection of water in devices like storm sewers, increased erosion and sedimentation, and irrigation and sprinkler systems can affect water flow to caves. Altering the quantity of water, its organic content, the timing and extent of flood pulses, or droughts may negatively impact the listed species.

Karst ecosystems are heavily reliant on surface plant and animal communities to maintain nutrient flows, reduce sedimentation, and resist exotic and invasive species. As the surface around a cave entrance or over the associated karst ecosystem is developed, native plant communities are often replaced with impermeable cover or exotic plants from nurseries. The abundance and diversity of native animals may decline due to decreased food and habitat, combined with increased competition and predation from urban, exotic, and pet species. As native surface plant and animal communities are destroyed, food and habitat once available to trogloxenes decreases. Destruction of native plant communities can lead to increased erosion that causes sedimentation within caves. It is necessary to maintain the native woodland and grassland communities; therefore, a perimeter area is needed to shield the core vegetation habitat from impacts associated with edge effects or disturbance from adjacent urban development (Lovejoy
et al.
1986, p. 284; Yahner 1988, pp. 333-334). Effects from such impacts can include increases in invasive species and pollutants, and changes in microclimates, which can adversely affect the listed species by impacting nutrient cycling processes important in cave/karst dynamics.

Much of the habitat occupied by the Bexar County invertebrates is particularly sensitive to groundwater contamination because little or no filtration occurs, and water penetrates rapidly through bedrock conduits (White 1988, p. 149). The ranges of these species are becoming increasingly urbanized, and, thereby, they are becoming more susceptible to contaminants including sewage, oil, fertilizers, pesticides, herbicides, seepage from landfills, pipeline leaks, or leaks in storage structures and retaining ponds. Activities on the surface, such as disposing of toxic chemicals or motor oil, can contaminate caves (White 1988, p. 388). Materials like cleaning agents, industrial chemicals, and heavy metals can also easily infiltrate subterranean ecosystems. Contamination of karst habitat can also occur from air pollutants and improper disposal of litter, motor oil, batteries, or other household products in or near caves (White 1988, pp. 399-400).

Continued urbanization will increase the likelihood that karst ecosystems are polluted by contamination from leaks and spills, which often have occurred in Bexar County. The Texas Commission on Environmental Quality (TCEQ 2010, pp. TCEQ-5 to TCEQ-8) summarized information on groundwater contamination reported by a number of agencies, and listed 109 groundwater contamination cases that occurred in Bexar County between 1980 and 2000, the majority of them spills or leaks of petroleum products. Groundwater contamination poses a threat to entire karst ecosystems and is particularly difficult to manage because pollutants can originate far from the sensitive karst site and flow rapidly through the subsurface (White 1988, pp. 387-388).

Fire ants are a pervasive, nonnative ant species originally introduced to the United States from South America over 50 years ago, and are an aggressive predator and competitor that has spread across the southern United States. They often replace native species, and evidence shows that overall arthropod diversity, as well as species richness and abundance, decreases in infested areas. Fire ants pose a major threat to the listed invertebrates in Bexar County through direct predation and competition with native species (such as cave crickets) for food resources. This threat is exacerbated by edge effects associated with the soil disturbance and disruption to native communities that accompany urbanization (refer to previous detailed discussion in Background).

Maintaining native vegetation communities greater than 12 ac (5 ha) may help sustain native ant populations and further deter fire ant infestations

(Porter
et al.
1988, p. 914; 1991, p. 869). On Camp Bullis Military Reservation, in Bexar and Comal Counties, Texas, caves are located in large expanses of undeveloped land. Although there is some ground disturbance in portions of the area, caves on Camp Bullis had less fire ant infestation compared to caves in more urbanized areas even prior to beginning a fire ant treatment regime (Veni and Associates 1999, p. 55). In addition, Suarez
et al.
(1998, p. 2041) found that protection of a core area zone at least 330 ft (100 m) wide helps to reduce the severity of fire ant infestations.

Karst invertebrates in central Texas are especially susceptible to fire ant predation because most caves are relatively short and shallow. The hot dry weather may also encourage fire ants to move into caves during summer months, and cold weather may cause them to seek refuge or prey in the caves during the winter. Fire ants have been found within and near many caves in central Texas and have been observed feeding on dead troglobites, cave crickets, and other species within caves (Elliott 1992, p. 13; 1994, p. 15; 2000, pp. 668, 678; Reddell 1993a, p. 10; Taylor
et al.
2003, p. 3). Besides direct predation, fire ants threaten listed invertebrates by reducing the nutrient input that fuels the karst ecosystem. Taylor
et al.
(2003, p. 3) found that cave crickets often arrived before fire ants at baits placed above ground at night, but the arrival of fire ants corresponded to the departure of cave crickets, indicating competition for at least some food resources. Of 36 caves visited during status surveys for the 9 Bexar County karst invertebrates, fire ants were found in 26 of them (Reddell 1993a, p. 32).

In summary, threats to the nine Bexar County invertebrates include clearing of vegetation for commercial or residential development, road building, quarrying, or other purposes. Infestation by nonnative vegetation causes adverse changes in the plant and animal community and possibly in the moisture availability. An increase in fire ants can occur with development and cause competition with and predation on other invertebrates in the karst ecosystem. In addition, filling cave features for construction, ranching, or other purposes can adversely affect the listed invertebrate species by reducing nutrient input, reducing small mammal access, and changing moisture regimes. Excavation for construction or operation of quarries can directly destroy karst features occupied by any of the nine Bexar County invertebrates, including the mesocaverns they use. Examples of management that would alleviate these threats include: (1) Protecting native vegetation around occupied karst features and overlying connected mesocaverns, cave cricket foraging areas, surface and subsurface drainage basins, temperature and humidity in karst features and mesocaverns; (2) protecting subsurface karst habitat around the cave footprint to allow movement of karst invertebrates through mesocaverns; (3) controlling fire ants around cave features and within the cave cricket foraging area; (4) preventing unauthorized access to karst features by installing fencing and cave gates; and (5) keeping the immediate areas surrounding cave features free from sources of contamination.

Criteria Used To Identify Critical Habitat

As required by section 4(b) of the Act, we used the best scientific and commercial data available in determining areas within the geographical area occupied at the time of listing that contain the features essential to the conservation of the nine Bexar County invertebrates, and areas outside of the geographical area occupied at the time of listing that are essential for the conservation of the nine Bexar County invertebrates. We relied on information in presence/absence survey reports submitted during project consultations with the Service, annual reports on research and recovery activities conducted under a section 10(a)(1)(A) scientific permit, annual 10(a)(1)(B) HCP reports, section 6 species status reports, and literature published in peer-reviewed journals. We also used information from the proposed (67 FR 55063; August 27, 2002) and final (68 FR 17155; April 8, 2003) critical habitat rules, draft recovery plan (Service 2008), and other information in our files. We are not currently proposing any areas outside the geographical area presently occupied by the species because occupied areas are sufficient for the conservation of the species.

Critical habitat units were delineated by creating approximate areas for the units by screen-digitizing polygons (map units) using ArcMap (Environmental Systems Research Institute, Inc.). We defined the boundaries of each unit based on the criteria below:

(1) We identified all areas known to be occupied by the species. We used verified identifications of specimens by recognized species experts. In the case of Madla Cave meshweaver, we also used genetic identification (Paquin and Hedin 2004, p. 3244).

(2) We included the cave footprint with the surface and subsurface drainage areas of the cave, where known.

(3) We included the cave cricket foraging area that is a 344-ft (105-m) circle around the cave entrance (Taylor
et al.
2005, p. 97), plus an additional 330-ft (100-m) distance to protect against edge effects from invasive species (Lovejoy
et al.
1986, p. 263; Wilcove
et al.
1986, pp. 249-250; Laurance 1991, p. 206; Laurance and Yensen 1991, pp. 78-79; Kapos
et al.
1993, p. 425; Andren 1995, p. 237; Reed
et al.
1996, p. 1102; Burke and Nol 1998, p. 96; Didham 1998, p. 397; Suarez
et al.
1998, p. 2047).

(4) We included contiguous geological formations of Karst Zone 1 (areas known to contain one or more of the nine Bexar County invertebrates) to protect mesocaverns likely connected to the caves to a distance of 0.3 mi (0.5 km) from the cave entrance (Kemble White, SWCA, pers. comm., 2010; White 2006, pp. 97-99).

(5) We also included native vegetation of an area of at least 100 ac (40 ha) needed to support the diversity of native plant species normally found in the Edwards Plateau communities and in their normal abundance (Service 2008, pp. B-9 to B-12). This number was derived for woodlands by examining studies of Van Auken
et al.
(1979, p. 170), Van Auken
et al.
(1980, pp. 30-31), Van Auken
et al.
(1981, pp. 1251-1253), and analysis by Dr. Kathryn Kennedy (Center for Plant Conservation, pers. comm. 2002), and Lynch (1962, p. 679; 1971, p. 890). Critical Habitat Units 10a, 10b, 11a through d, and 24 have areas less than 100 ac (40 ha) being proposed for critical habitat, but these units still meet the criterion of having at least 100 ac (40 ha) of native vegetation surrounding the karst ecosystems. We reduced these proposed critical habitat units in size because some of their surface area is being exempted based on the Camp Bullis Military Reservation Integrated Natural Resources Management Plan (
see
Exemptions section below).

Using the distances between caves whose mesocaverns are likely connected as a guide, we analyzed distance from a cave through which karst invertebrates are likely to move through mesocaverns in Bexar County as part of this critical habitat proposed rule. We examined the information on the area around Camp Bullis and found it was not representative of many Bexar County caves, because of the unique geological conditions there. All of the Camp Bullis area caves were formed within the damage zone of a fault where

interconnected mesocaverns and entrance-less caves occur. Because the area is a fault zone, there are long distances of connectivity between mesocaverns. Rather than using the greater distance karst invertebrates are likely to move, we found 0.3 mi (0.5 km) to be a more realistic distance over which karst invertebrates potentially move through mesocaverns in Bexar County. We selected 0.3 mi (0.5 km) because of the connection distance of the mesocaverns of Robbers Cave and Hills and Dales Pit, which are located in another part of Bexar County, similar genetics between meshweavers in the caves, and the lack of faulting or other geological anomalies between them. We believe 0.3 mi (0.5 km) is a reasonable distance limit that karst invertebrates could move through mesocaverns. Although the genetics of the species in the caves are not identical, this represents the best available information we have. The 0.3-mi (0.5-km) distance was in Karst Zone 1, and the caves do not have geologic barriers to movement between them. Based on the best available information, we believe it is an appropriate distance to represent potential use of mesocaverns by the nine Bexar County invertebrates.

An area with a 0.3-mi (0.5-km) radius is equal to 179 ac (72 ha). We used this 179-ac (72-ha) area around cave locations with known occurrences as a guide for mapping the physical and biological features essential to the conservation of the nine Bexar County invertebrates. We designated all of Karst Zone 1 within the 0.3-mi (0.5-km) radius of the cave. In units where we needed additional surface habitat to reach the 100-ac (40-ha) target for native vegetation, we included adjacent surface habitat over Karst Zone 1 surface habitat. If native vegetation was not available in a Karst Zone 1 area, we used other Karst Zones to reach the target surface acreage. In units that are all Karst Zone 1 and are fully vegetated, the 179-ac (73-ha) area of native vegetation derived using the 0.3-mi (0.5-km) radius circle around cave entrances is included. In units with high levels of surface impact or with only a small amount of Karst Zone 1, we went outside the 0.3-mi (0.5-km) radius around cave locations to include at least 100 ac (40 ha) of vegetation.

When the 0.3-mi (0.5-km) distance around individual cave entrances in Karst Zone 1 (areas known to contain one or more of the nine Bexar County invertebrates) or the expanded vegetation community overlapped, we included caves in the same unit. We did not include area for cave cricket foraging if it was on the other side of an urban edge like a major roadway because such edges act as barriers to cricket movement.

In this proposed critical habitat for the nine Bexar County invertebrates, we selected areas based on the best scientific data available that possess those physical and biological features essential to the conservation of the species and that may require special management considerations or protection. We identified critical habitat units that are known to be occupied based on one or more surveys that resulted in the collection of a specimen from the karst feature and verification of species by a taxonomic expert. Even though the nine Bexar County invertebrates spend their entire lives underground, we included specific surface features when identifying critical habitat units because they are important drainage links into the caves and because surface habitat is needed to support the plant and animal communities upon which the invertebrates depend. Because some of the rarer species are difficult to collect, and it may take many attempts to collect even more common species, we included all locations with historic records of species occupancy, regardless of date. In the case of the Madla Cave meshweaver, in addition to morphological identifications, we used genetic identification of specimens to verify known locations (Paquin and Hedin 2004, p. 3244). We determined the units based on the presence of one or more of the defined PCEs and the kind, amount, and quality of habitat associated with those occurrences. Some of the units contain the appropriate quantity and distribution of PCEs to support the life cycle stages we have determined as essential to the conservation of the species. Other units or portions of units contain only a portion of the PCEs. We did this because the PCEs that are present can support the listed species, even though not all PCEs are present. For example, surface habitat without a healthy plant and animal community can continue to support listed invertebrates below the surface, and clean water from modified surface areas can provide the humidity needed by the listed invertebrates.

When determining proposed critical habitat boundaries within this proposed rule, we made every effort to avoid including developed areas such as lands covered by buildings, pavement, and other structures which lack the surface PCEs for the nine Bexar County invertebrates. However, we included some developed areas even though such lands lack the surface PCEs for the nine Bexar County invertebrates. We included these developed lands because they contain the subsurface PCEs needed by the invertebrates, such as karst-forming rock containing subterranean spaces. The scale of the maps we prepared under the parameters for publication within the Code of Federal Regulations may not reflect the exclusion of developed lands that did not contain subsurface PCEs. Any such lands that do not contain subsurface PCEs inadvertently left inside critical habitat boundaries shown on the maps of this proposed rule have been excluded by text in the proposed rule and are not proposed for designation as critical habitat. Therefore, if the critical habitat is finalized as proposed, a Federal action involving these lands that do not contain subsurface PCEs would not trigger section 7 consultations with respect to critical habitat and the requirement of no adverse modification unless the specific action would affect the PCEs in the adjacent critical habitat.

We are proposing for designation as critical habitat units that we believe were occupied at the time of listing and which contain one or more PCEs to support life-history functions essential for the conservation of the species. For some units, we did not know at the time of listing that these areas were occupied because surveys had not yet been conducted or the species had not yet been found in previous surveys. These sites not known to be occupied at the time of listing are being proposed for critical habitat because they are essential for the conservation of the species. We are not including any unoccupied areas in this rule. In addition, units are proposed for designation based on sufficient PCEs being present to support any of the nine Bexar County invertebrates' life processes. Some units contain all PCEs and support multiple life processes. Some units contain only a portion of the PCEs necessary to support one or more of the nine Bexar County invertebrates' particular use of that habitat.

Summary of Changes From Previously Designated Critical Habitat

The areas identified in this proposed rule constitute a proposed revision of the areas we designated as critical habitat for the seven Bexar County invertebrates on April 8, 2003 (68 FR 17155). The significant differences between the 2003 rule and this proposal are:

(1) This proposed rule, which is based partly on new occupancy information since we originally proposed critical habitat (Service 2008, pp. D-4-D-12; J. Krejca, Zara Environmental Consultants,

pers. comm., 2010; K. White, SWCA Environmental Consultants, pers. comm. 2010), includes 35 units, totaling 6,906 ac (2,795 ha), with 13 units that were not previously designated. This proposed rule results in an increase of 5,843 ac (2,365 ha) from the currently designated critical habitat (1,063 ac in 22 units). Seven new units are being proposed around Camp Bullis. We are also proposing four new units that were previously excluded on Government Canyon State Natural Area (GCSNA).

(2) Areas where the Government Canyon Bat Cave meshweaver and the Government Canyon Bat Cave spider occur on the GCSNA were previously excluded from the 2003 final critical habitat designation (68 FR 17155; April 8, 2003). In the 2003 designation, we determined that these areas did not meet the definition of critical habitat found in section 3(5)(A)(i) of the Act because the conservation plans for the caves on GCSNA provided adequate management and protection to the level that the area did not require special management. However, the Courts have invalidated this approach. In
Center for Biological Diversity
v.
Norton
(240 F.Supp.2d 1090 (D. Ariz. 2003)), the Court stated the actual presence of a management plan shows that special management is needed. Accordingly, we have reassessed whether these areas meet the definition of critical habitat in light of the Court's ruling. We have determined these areas meet the definition of critical habitat and have included them in this proposal (
see
Proposed Critical Habitat Designation section below).

(3) This proposal critical habitat rule includes a larger subterranean area around each occupied feature than the previous final rule (68 FR 17155; April 8, 2003). In this proposed rule, we use a distance of 0.3 mi (0.5 km) from occupied features in Karst Zone 1 as a criterion to delineate critical habitat. We base this distance on the karst geology and species genetics of Bexar County karst invertebrates (White 2006, pp. 76-78) and have better information available today (
see Subsurface Environment
above). In the 2003 final rule (68 FR 17155; April 8, 2003), we did not use a similar criterion, but stated that the distance that these invertebrates go from the cave into the surrounding karst is unknown.

(4) We increased the cave cricket foraging area from 164 ft (50 m) in the 2003 final rule (68 FR 17155; April 8, 2003) to 344 ft (105 m) in this proposed rule based on the Taylor
et al.
(2005, p. 97) study. In addition, we increased the minimum vegetation area in each unit from 40 ac (16 ha) to 100 ac (40 ha) based on the Draft Bexar County Karst Invertebrate Recovery Plan (2008, p. B-7). We use a combination of woodland, grassland, and a buffer area to protect against edge effects in this proposed rule.

(5) We are proposing as critical habitat all occupied sites for the nine Bexar County invertebrates except those that meet the criteria for exemption, as all of these sites are essential to the conservation of the species.

Proposed Critical Habitat Designation

We are proposing 35 units as critical habitat for the nine Bexar County invertebrates. For comparison, we numbered the units so that they are as consistent as possible with the previous proposed and final critical habitat rules. However, there are 13 additional units. Most additional units were assigned the next highest number, but those adjacent to Camp Bullis were assigned alphanumeric designations. For example, 10a and 10b were assigned to show their relationship to the previously proposed habitat on Camp Bullis. The critical habitat areas described below constitute our current best assessment of areas that meet the definition of critical habitat for the nine Bexar County invertebrates. All units we are proposing for the nine Bexar County invertebrates were occupied at the time of listing and are still currently occupied. Table 2 lists the proposed units, occupied caves, unit ownership, and listed species in each unit.

Table 2—Unit number, names of known occupied caves, unit size, land ownership, and listed species that occur within each proposed critical habitat unit

Unit

Known occupied caves
in unit

Size of unit in acres (hectares)
Land owner-ship type

Listed species
in unit

1a

Bone Pile Cave
Surprise Sink

238 ac (96 ha)
State

R. infernalis.

C. madla.

1b

Government Canyon
Bat Cave

178 ac (72 ha)
State

C. vespera.

N. microps.

R. exilis..

R. infernalis.

1c
Lost Pothole
178 ac (72 ha)
State

C. madla.

1d

Dancing Rattler Cave
Lithic Ridge Cave
Hackberry Sink

349 ac (141 ha)
State

C. madla.

R. exilis.

R. infernalis.

1e

Canyon Ranch Pit *
Continental Park Cave
Creek Bank Cave
Fat Man's Nightmare Cave*
Pig Cave
San Antonio Ranch Pit
Scenic Overlook Cave*
Tight Cave

690 ac (279 ha)

State
City
Private

R. infernalis.

R. exilis.

B. venyivi.

C. madla.

1f
10K Cave
178 ac (72 ha)
State

R. infernalis.

2

Logan's Cave
Madla's Drop Cave

252 ac
(102 ha)

Private

C. madla.

R. exilis.

R. infernalis.

3

Helotes Blowhole *
Helotes Hilltop Cave *

125 ac (51 ha)
Private

C. madla.

R. exilis.

R. infernalis.

B. venyivi.

4

Kamikazi Cricket Cave
Mattke Cave
Scorpion Cave

255 ac (103 ha)
Private

R. exilis.

R. infernalis.

5
Christmas Cave

117 ac
(47 ha)

Private

C. madla.

R. exilis.

R. infernalis.

B. venyivi.

6

John Wagner Ranch
Cave No. 3 *

105 ac (42 ha)

Private
City

C. madla.

R. exilis.

R. infernalis.

7
Young Cave No. 1
158 ac (64 ha)
Private

R. exilis.

8

Three Fingers Cave
Hills and Dales Pit *
Robber's Cave

471 ac (191 ha)

Private
City

C. madla.

R. infernalis.

R. exilis.

9

Mastodon Pit
Feature No. 50
La Cantera Cave No. 1
La Cantera Cave No. 2

286 ac (116 ha)

State
Private

C. madla.

R. exilis.

10a

Low Priority Cave
1

67 ac (27 ha)
City Private

R. infernalis.

10b

Flying Buzzworm Cave
1

66 ac (27 ha)
City

R. infernalis.

11a

Up The Creek Cave
1

21 ac (8.5 ha)
Private

R exilis.

11b

Bunny Hole
1

16 ac 6.5 ha
Private

R. exilis.

11c

Poor Boy Baculum Cave
1

21 ac 8.5 ha
Private

R exilis.

11d

Root Toupee Cave
1

52 ac
21 ha

Private

R. exilis.

11e
Blanco Cave
102 ac (41 ha)
Private

R. exilis.

12

Hairy Tooth Cave
Ragin' Cajun Cave

371 ac (150 ha)
Private

R. exilis.

13
Black Cat Cave
187 ac (76 ha)
Private

R. exilis.

14

Game Pasture Cave No. 1
King Toad Cave
Stevens Ranch Trash Hole Cave

330 ac (134 ha)
Private

R. infernalis.

15

Braken Bat Cave
Isopit
Obvious Little Cave
Wurzbach Bat Cave

339 ac (137 ha)
Private

C. venii.

R. infernalis.

16
Caracol Creek Coon Cave
194 ac (76 ha)
Private

R. infernalis.

17
Madla's Cave *
114 ac (46 ha)
Private

C. madla.

R. infernalis.

19
Genesis Cave
142 ac (57 ha)
Private

R. infernalis.

20
Robber Baron Cave
247 ac (100 ha)
Private

T. cokendolpheri.

C. baronia.

21

Hornet's Last Laugh Pit
Kick Start Cave
Springtail Crevice

396 ac (160 ha)

City
Private

R. exilis.

22
Breathless Cave
178 ac (72 ha)

City
Private

C. madla.

23
Crownridge Canyon Cave
178 ac (72 ha)

City
Private

R. infernalis.

24

Peace Pipe Cave
1

11 ac (4.5 ha)
Private

R. exilis.

25
OB3
177 ac (72 ha)
Private

C. baronia.

26
Max and Roberts Cave
117 ac (47 ha)
Private

R. infernalis.

Totals
62 caves 35 Units
6,906 ac (2,795 ha)

* Indicates caves and associated lands managed under the La Cantera HCP.

1.
Cave is located on Camp Bullis; proposed critical habitat is outside Camp Bullis but most likely includes mesocaverns of the cave.

Note:
Area sizes may not sum due to rounding.

Table 3 shows whether the critical habitat units were known to be occupied at the time of listing. At the time of listing, we were unaware of several caves or whether some of the caves we did know about were occupied. Therefore, a “No” is listed in Table 3 for units where surveys had not yet been conducted or the species had not yet been found in previous surveys. All units are currently occupied.

Table 3—Occupancy of One or More of the Nine Bexar County Invertebrates by Proposed Critical Habitat Units

Unit
Known to be occupied at time of listing?
Currently occupied?

1a
Yes
Yes.

1b
Yes
Yes.

1c
Yes
Yes.

1d
Yes
Yes.

1e
No
Yes.

1f
No
Yes.

2
Yes
Yes.

3
Yes
Yes.

4
Yes
Yes.

5
Yes
Yes.

6
Yes
Yes.

7
Yes
Yes.

8
Yes
Yes.

9
Yes
Yes.

10a
Yes
Yes.

10b
Yes
Yes.

11a
Yes
Yes.

11b
Yes
Yes.

11c
Yes
Yes.

11d
No
Yes.

11e
No
Yes.

12
Yes
Yes.

13
Yes
Yes.

14
Yes
Yes.

15
Yes
Yes.

16
Yes
Yes.

17
Yes
Yes.

19
Yes
Yes.

20
Yes
Yes.

21
No
Yes.

22
No
Yes.

23
No
Yes.

24
No
Yes.

25
No
Yes.

26
No
Yes.

Table 4 shows the units and total area of proposed critical habitat for each of the nine Bexar County invertebrates.

Table 4—Unit Number and Total Area of Proposed Critical Habitat for Each of the Nine Bexar County Invertebrates

Listed species
Critical habitat unit(s)
Total area of critical habitat acres (hectares)

R. exilis
(ground beetle, no common name)

1b, 1d, 1e, 2, 3, 4, 5, 6, 7, 8, 9, 11a, 11b, 11c, 11d, 11e, 12, 13, 21, 24
4,163 ac (1,684 ha).

R. infernalis
(ground beetle, no common name)

1a, 1b, 1d, 1e, 1f, 2, 3, 4, 5, 6, 8, 10a, 10b, 14, 15, 16, 17, 19, 23, 26
4,505 ac (1,823 ha).

Helotes mold beetle (
B. venyivi
)

1e, 3, 5
932 ac (377 ha).

Cokendolpher Cave harvestman (
T. cokendolpheri
)

20
247 ac (100 ha).

Robber Baron Cave meshweaver (
C. baronia
)

20, 25
424 ac (172 ha).

Madla Cave meshweaver (
C. madla
)

1a, 1c, 1d, 1e, 2, 3, 5, 6, 8, 9, 17, 22
3,103 ac (1,256 ha).

Braken Bat Cave meshweaver (
C. venii
)

15
339 ac (137 ha).

Government Canyon Bat Cave meshweaver (
C. vespera
)

1b
178 ac (72 ha).

Government Canyon Bat Cave spider (
N. microps
)

1b
178 ac (72 ha).

We present brief descriptions of all units, and reasons why they meet the definition of critical habitat for the nine Bexar County invertebrates below.

Unit 1a

We are proposing to designate 238 ac (96 ha) of State-owned land in Unit 1a located in northwestern Bexar County in the northwestern part of Government Canyon State Natural Area (GCSNA) in the Government Canyon KFR for the Madla Cave meshweaver and
R. infernalis.
The GCSNA is an area of

approximately 8,622 ac (2,688 ha) owned and managed by the Texas Parks and Wildlife Department (TPWD). The GCSNA is accessible to the public under certain restrictions. This unit is all undeveloped native woodland and is crossed by a wet weather stream and a trail. Unit 1a contains Surprise Sink Cave, which is occupied by Madla Cave meshweaver and
R. infernalis,
and Bone Pile Cave, which is occupied by
R. infernalis.
The Surprise Sink Cave may also be occupied by Government Canyon Bat Cave spider, but the specimen collected has not been confirmed (Zara 2010, p. 2). The caves in this unit were occupied at the time of listing, and the unit contains all the PCEs for the species.

The main threat in this unit is infestation of fire ants. The GCSNA currently has a management plan in place that includes treating for fire ants and managing for the benefit of the Madla Cave meshweaver and
R. infernalis.

The unit was delineated by drawing a radius of 0.3 mi (0.5 ha) around each of the two caves and connecting the edges of the overlapping circles. Unit 1a is all Karst Zone 1.

Unit 1b

In Unit 1b, we are proposing 178 ac (72 ha) of State-owned land located in northwest Bexar County in the western portion of the GCSNA in the Government Canyon KFR for the Government Canyon Bat Cave meshweaver, Government Canyon Bat Cave spider,
R. exilis,
and
R. infernalis.
Land within the proposed unit consists of undeveloped native vegetation. However, there are several one-lane gravel roads that serve primarily as pedestrian trails within the State natural area. A small portion of the vegetation appears to have been cleared for ranching prior to TPWD ownership. The unit contains one cave, Government Canyon Bat Cave, which is the only known cave occupied by the Government Canyon Bat Cave meshweaver. The cave is also occupied by Government Canyon Bat Cave spider,
R. exilis,
and
R. infernalis.
The Government Canyon Bat Cave was occupied at the time of listing, and the unit contains all the PCEs.

The main threat to species in this unit is infestation of fire ants. While GCSNA currently has a management plan in place that includes treating for fire ants and managing for the benefit of the species.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around the cave. The unit is all Karst Zone 1.

Unit 1c

We are proposing 178 ac (72 ha) of State-owned land in Unit 1c located in northwestern Bexar County in the central part of GCSNA in the Government Canyon KFR for the Madla Cave meshweaver. This unit is primarily undeveloped native woodland that is crossed by a hiking trail. There is only one cave in this unit, Lost Pothole Cave. The cave was occupied at the time of listing, and the unit contains all the PCEs for the species. A small amount of the woody vegetation in this unit has been cleared in the past for ranching prior to TPWD ownership.

The main threat to the cave is infestation of fire ants. While GCSNA currently has a management plan in place that includes treating for fire ants and managing for the benefit of the species.

This unit was delineated by drawing a 0.3-mi (0.5-km) radius around the cave. The entire unit is Karst Zone 1.

Unit 1d

In Unit 1d, we are proposing 349 ac (141 ha) of State-owned land located in northwestern Bexar County in the central part of the GCSNA in the Government Canyon KFR for the Madla Cave meshweaver,
R. exilis,
and
R. infernalis
. This unit is wooded and undeveloped. The unit is primarily native vegetation, but small portions of the unit appear to have been thinned in the past for ranching prior to TPWD ownership. Unit 1d contains three caves: Dancing Rattler Cave, Lithic Ridge Cave, and Hackberry Sink. The Lithic Ridge Cave is occupied by Madla Cave meshweaver,
R. exilis,
and
R. infernalis.
The Dancing Rattler Cave and Hackberry Sink are occupied by
R. infernalis.
The caves in this unit were occupied at the time of listing and contain all the PCEs for the species.

The main threat to the unit is infestation of fire ants, but the GCSNA currently has a management plan in place that includes treating for fire ants.

This unit was delineated by drawing a 0.3-mi (0.5-km) radius around each of the three caves and connecting the edges of the overlapping circles. The entire unit is Karst Zone 1.

Unit 1e

We are proposing 690 ac (279 ha) in Unit 1e in northwestern Bexar County that includes the northeastern part of State-owned GCSNA, adjacent City of San Antonio-owned land, and private land in the Government Canyon KFR for the Madla Cave meshweaver,
R. infernalis, R. exilis,
and Helotes mold beetle. The majority of Unit 1e consists of undeveloped land with the exception of several small private and/or county roads. Woody vegetation has been thinned for ranching on a small area of the northeastern part of the unit. Unit 1e contains eight caves. Four caves are occupied by Madla Cave meshweaver (Fat Man's Nightmare Cave, Pig Cave, San Antonio Ranch Pit, and Scenic Overlook Cave). Fat Man's Nightmare Cave is also occupied by
R. infernalis;
Pig Cave is also occupied by
R. infernalis
and
R. exilis;
San Antonio Ranch Pit is occupied by
R. infernalis, R. exilis,
and Helotes mold beetle; and Scenic Overlook Cave is occupied by
R. infernalis
and Helotes mold beetle. The unit also contains Canyon Ranch Pit and Continental Park Cave, which are occupied by
R. infernalis,
Creek Bank Cave occupied by
R exilis,
and Tight Cave occupied by
R. exilis
and Helotes mold beetle. It is not known if the caves were occupied at the time of listing, but they currently are, and the unit contains all the PCEs for the species.

The major threats to the unit are infestation of fire ants and vandalism from unauthorized access. Five of the caves in this unit are owned by GCSNA, and they currently have a management plan in place that includes treating for fire ants and managing for the benefit of the species.

Three of the eight known occupied caves within this unit and their associated preserve lands are being considered for exclusion. The 75-ac (30-ha) Canyon Ranch Preserve, which was acquired and is managed by La Cantera under their HCP, contains Canyon Ranch Pit, Fat Man's Nightmare Cave, and Scenic Overlook Cave. According to the La Cantera HCP, these three caves and the surrounding preserve lands will be managed in perpetuity for the conservation of the species.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around each of the eight caves and joining the edges of the overlapping circles. The entire unit is Karst Zone 1.

Unit 1f

For Unit 1f, we are proposing 178 ac (72 ha) of State-owned land in northwest Bexar County in the southeastern part of the GCSNA in the Government Canyon KFR for
R. infernalis.
The unit is entirely native woodland, but a small amount appears to have been cleared in the past for ranching prior to TPWD ownership. It contains only one cave, which is named 10k Cave. We do not know if the cave was occupied at the time of listing, but it is currently, and the unit contains all the PCEs for the species.

The major threats to Unit 1f are infestation of fire ants. The GCSNA currently has a management plan in place that includes controlling fire ants and managing for the benefit of the species.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around the cave. The unit is all Karst Zone 1.

Unit 2

We are proposing 252 ac (102 ha) of private land in Unit 2 located in northwestern Bexar County north of Bandera Road and southeast of High Bluff Road in the Helotes KFR for Madla Cave meshweaver,
R. infernalis,
and
R. exilis.
This unit contains a mix of large, wooded tracts with several residential buildings, cleared areas, a quarry on the southeastern edge, and private or county roads. The entire unit is private land.

Unit 2 contains two caves. The Madla's Drop Cave is occupied by Madla Cave meshweaver and
R. infernalis.
This unit also contains Logan's Cave, which is occupied by
R. infernalis
and
R. exilis.
These caves were occupied at the time of listing, and parts of the unit contain all the PCEs for the species. There are two paved roads that cross the cave cricket foraging area of this unit and act as barriers to cricket movement.

This unit requires special management because of residential development. Threats include the potential for destruction of habitat from vandalism, contamination of the subsurface drainage area of the unit, drying of karst, reduction of nutrient input, and infestation of fire ants.

This unit was delineated constructing a 0.3-mi (0.5-km) radius around each of the two caves and connecting the edges of the overlapping circles. Areas of Karst Zone 3 karst along the western, northwestern, and southern portions of the unit were removed in order to substantially reduce fragmentation of the unit. The rest of Unit 2 is Karst Zone 1.

Unit 3

For Unit 3, we are proposing 125 ac (51 ha) of private land in northwestern Bexar County, east of Bandera Road and northwest of Scenic Loop in the Helotes KFR for the Madla Cave meshweaver,
R. infernalis, R. exilis,
and Helotes mold beetle. The unit contains relatively large, wooded tracts. This unit contains two caves, Helotes Blowhole and Helotes Hilltop. The Helotes Blowhole is occupied by Madla Cave meshweaver,
R. infernalis,
and
R. exilis.
The Helotes Hilltop Cave is occupied by Madla Cave meshweaver,
R. exilis,
and Helotes mold beetle. Both caves were occupied at the time of listing, and the unit contains all the PCEs for the species.

Threats include the potential for destruction of habitat from vandalism, contamination of the subsurface drainage area of the unit, and infestation of fire ants. In addition, the land along the northern side of the unit has been developed with residential homes. Unit 3 contains several small residential roads and is crossed by Bandera Road, a four-lane divided highway, in its southwestern corner. This unit does not include the entire 344-ft (105-m) cave cricket foraging area around Helotes Hilltop Cave in Karst Zone 3 because there is a paved road creates a barrier to cave cricket movement.

This unit was delineated by drawing a 0.3-mi (0.5-km) radius around each of the two caves and following the edge of Karst Zone 1 (Veni 2003) within the overlapping circles. Some areas of Zone 3 are included along the eastern boundary of the unit to include more of the cave cricket foraging area for Helotes Hilltop Cave. Areas of Zone 3 along all but a part of the northern portion of the unit were removed. The rest of Unit 3 is Karst Zone 1.

This unit is being considered for exclusion, because the two caves and the approximately 25 ac (10-ha) of land surrounding the caves were acquired under the La Cantera HCP. These caves and the surrounding preserve lands will be managed in perpetuity for the conservation of the species. The remainder of the unit requires special management because of the presence of roads and residential development.

Unit 4

For Unit 4, we are proposing 255 ac (103 ha) of private land in northwestern Bexar County, west of the intersection of Scenic Loop and Cross XD Road in the UTSA KFR for
R. exilis
and
R. infernalis.
Tower View Road and Cash Mountain Road cross the northern part of the unit, and Rafter S and Cross XD cross the southern part. Unit 4 contains three caves. The Kamikazi Cricket Cave is occupied by
R. exilis
and
R. infernalis.
The Mattke and Scorpion Caves are occupied by
R. infernalis.
These three caves were occupied at the time of listing, and parts of the unit contain all the PCEs for the species.

Several threats impact this unit, including the potential for destruction of habitat from vandalism and potential future development, contamination of the subsurface drainage area of the unit, drying of karst areas, reduction of nutrient input, and infestation of fire ants. In addition, this unit contains several residential roads, but no major roadways or highways. Lands surrounding Unit 4 consist of relatively large, residential tracts. The unit requires special management because of threats from existing and potential future residential development.

The unit was delineated by drawing a radius of 0.3-mi (0.5-km) around each of the three caves and removing most areas of Karst Zone 3 from the unit. Large portions of the northern, southern, and western edges of Karst Zone 3 inside the circle were removed. Some areas of Karst Zone 3 were included along the western, northern, and southern edges of the cave cricket protection areas of Kamikaze Cricket and Mattke Caves. The remainder of the unit is Karst Zone 1. The unit was expanded beyond the 0.3 mi (0.5 km) area to the east and south of Kamikaze Cricket Cave and to the north and east of Mattke and Scorpion Caves in order to include at least 100 ac (40 ha) of native vegetation.

Unit 5

In Unit 5, we are proposing 117 ac (47 ha) of private land in northwestern Bexar County, northwest of Cedar Crest Drive and north of Madla Ranch Road in the Helotes KFR for the
R. exilis, R. infernalis,
Helotes mold beetle, and Madla Cave Meshweaver. The unit contains a large tract of undeveloped woodland and several smaller, wooded tracts developed with homes and associated residential roads. This unit contains one cave, Christmas Cave, which is occupied by
R. exilis, R. infernalis,
Helotes mold beetle, and Madla Cave Meshweaver. The cave was occupied at the time of listing and parts of the unit contain all the PCEs for the species. However, there are homes and associated roads within the cave cricket foraging area of the cave.

The unit requires special management because of the presence of residential development and impending future development. Threats include the potential for destruction of habitat from development and vandalism, contamination of the subsurface drainage area of the unit, reduction of moisture and nutrients, and infestation of fire ants.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around the cave entrance and following the edge of Karst Zone 1 within the circle. Some areas of Zone 3 are included along the southeastern boundary of the unit to include the cave cricket foraging area for Christmas Cave. The rest of Unit 5 is Karst Zone 1.

Unit 6

For Unit 6, we are proposing 105 ac (42 ha) of private and City of San Antonio-owned land located in

northwestern Bexar County, bordered to the south by Menchaca Road and to the west by Morningside Drive in the UTSA KFR for the Madla Cave meshweaver,
R. exilis,
and
R. infernalis.
Unit 6 consists primarily of large, undeveloped, woodland tracts with several smaller areas developed with homes. The John Wagner Ranch Cave No. 3 is the only cave in this unit, and it is occupied by Madla Cave meshweaver,
R. exilis,
and
R. infernalis.
The cave was occupied at the time of listing, and the unit contains all the PCEs for species.

Threats to the unit include the potential for destruction of habitat from potential future development and vandalism, contamination of the subsurface drainage area of the unit, and infestation of fire ants.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around John Wagner Ranch Cave No. 3 and following the general boundary of Karst Zone 1, primarily the northeastern quadrant of the circle. A portion of the cave cricket foraging and protection area in Karst Zone 3 was included in the unit. The majority of land included in Unit 6 is in Karst Zone 1. The unit was expanded slightly outside the 0.3-mi (0.5-km) radius to the northern to eastern edge of the unit in order to include a minimum of 100 ac (40 ha) of native vegetation.

The John Wagner Ranch Cave No. 3 and approximately 4 ac (1.6 ha) surrounding the cave were acquired as part of the La Cantera HCP. Therefore, the cave and surrounding preserve lands will be managed in perpetuity for the conservation of the species. This part of the unit is being considered for exclusion in the final critical habitat rule.

Unit 7

We are proposing 158 ac (64 ha) of private land in Unit 7 located in northwestern Bexar County, south of Babcock Road near the intersection of Cielo Vista Drive and Luna Vista in the UTSA KFR for
R. exilis.
The unit is largely wooded, but there is some development in the north and eastern parts of the unit. Unit 7 contains one cave known as Young Cave No. 1 and it is occupied by
R. exilis.
The cave was occupied at the time of listing, and the unit contains all the PCEs for the species.

This unit requires special management because of residential development. There is a new road, Camino del Sol, which ends east of Young Cave No. 1, and is located within the cave cricket foraging area. Also, residential homes are located on the south part of this unit in the cave cricket protection area. Other threats include the potential for destruction of habitat from vandalism and new construction, contamination of the subsurface drainage area, drying of karst features, reduction of nutrient input, and infestation of fire ants.

Unit 7 was delineated by drawing a radius of 0.3 mi (0.5 km) around Young Cave No. 1 and including the general boundary of Karst Zone 1 in the circle. A portion of the cave cricket foraging and protection area in Karst Zone 3 is included in the unit.

Unit 8

In Unit 8, we are proposing 471 ac (191 ha) of private and City of San Antonio's Medallion Park land located in northwestern Bexar County in the UTSA KFR for the Madla Cave meshweaver,
R. exilis,
and
R. infernalis.
The unit is bordered on the northwest by Kyle Seale Parkway, on the northeast by Moss Brook Drive, and on the south by Cotton Trail Lane. Some of the land is undeveloped woodland, but some areas on the edges of the unit have been developed or have been cleared for future development. This unit contains three caves: Three Fingers Cave, Hills and Dales Pit, and Robber's Cave. The Hills and Dales Pit and Robber's Cave are occupied by Madla Cave meshweaver,
R. exilis,
and
R. infernalis.
The Three Fingers Cave is occupied by
R. exilis
and
R. infernalis.
This unit was occupied at the time of listing, and portions of the unit contain all the PCEs for the species.

The southeastern, extreme southern, northeastern, and northwestern portions of this unit have been subdivided and developed with homes. Several roads cross the unit. The extreme southern portion of the unit has higher density development. Part of the unit has been developed with residential roads, but it currently contains no homes. Threats in this unit include the potential for destruction of habitat from vandalism and potential future development, contamination of the subsurface drainage area of the unit, drying of karst features, reduction of nutrient input, and infestation of fire ants.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around each of the three caves and connecting the resulting overlapping circles. Unit 8 is entirely Karst Zone 1.

The Hills and Dales Pit and approximately 70 ac (28 ha) surrounding the cave have been acquired as part of the La Cantera HCP. Therefore, the cave and surrounding preserve lands will be managed in perpetuity for the conservation of the species. This area is being considered for exclusion from the final critical habitat rule.

Unit 9

For Unit 9, we are proposing 286 ac (116 ha) of State and private land in north-central Bexar County on both sides of Loop 1604 and east of the Loop 1604 intersection with IH 10 in the UTSA KFR for the Madla Cave meshweaver and
R. exilis.
There is a large tract of undeveloped woodland to the south and dense commercial development in the north. Also, this unit has a major shopping mall in the northwestern area. The unit is bordered to the west by the University of Texas at San Antonio campus and to the east by commercial development. Unit 9 contains four caves: Mastodon Pit, Feature No. 50, La Cantera Cave No. 1, and La Cantera Cave No. 2. La Cantera Cave No. 1 is occupied by Madla Cave meshweaver and
R. exilis.
Feature No. 50 is occupied by Madla Cave meshweaver. The two other caves, Mastodon Pit and La Cantera Cave No. 2, contain only
R. exilis.
All four caves were occupied at the time of listing, and the southern part of the unit has all of the PCEs for the species. Most of the northern part of the unit does not contain the PCE of a healthy surface community of native plants and animals. We are proposing it on the basis that it contains the PCE of karst-forming rock containing subterranean spaces.

Because of the commercial development and roadways that border and cross the unit, Unit 9 requires special management. Threats include the potential for destruction of habitat from vandalism and potential future development, contamination of the subsurface drainage area of the unit, drying of karst features from impervious cover, reduction of nutrient input, and infestation of fire ants.

This unit was delineated by drawing a radius of 0.3 mi (0.5 km) around each of the four caves and connecting the resulting overlapping circles. The majority of the land included in Unit 9 is Karst Zone 1.

Unit 10a

We are proposing 67 ac (27 ha) of private and City of San Antonio's Eisenhower Park land in Unit 10a located in north central Bexar County outside the easternmost portion of the southern boundary of Camp Bullis (a military reservation) in the Stone Oak KFR for
R. infernalis.
The eastern part of the unit is in the City of San Antonio's Eisenhower Park, which is used for picnicking, camping, hiking, jogging, and nature study. The

remainder of the unit is in private ownership. The unit is almost entirely undeveloped, but contains some unpaved roads and hiking trails. This unit was occupied at the time of listing, and contains all the PCEs of the species.

The Low Priority Cave is located on Camp Bullis and contains
R. infernalis.
However, the Low Priority Cave's entrance is not included i

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2011-3038. Public record. Not legal advice.