An Incidental Take Permit for Endangered Karst Invertebrates in Bexar County, Texas Steven W. Carothers, Ph.D Kemble White Casey Berkhouse SWCA, Inc., Environmental Consultants 1712 Rio Grande Suite C, Austin, Texas, 78701 Phone: 512 476-0891

Abstract

Nine species of cave invertebrates presently known only from karst topography in north and northwest Bexar County, Texas, were listed as endangered on December 26, 2000. Species listed include: two troglobitic ground beetles, Rhadine infernalis and R. exilis, a mold beetle, Batrisodes venyivi, an eyeless harvestman, , and five eyeless , baronia, C. madla, C. Venii, C. vespera, and Neoleptoneta microps. A local landowner with three small caves, all occupied by one or two of the listed species, has recently applied for a Section 10(a) incidental take permit to close one of the caves and preserve, in perpetuity, each of the other two caves in small (one-acre) preserves. The applicant and the authors worked with the United States Fish and Wildlife Service (Austin, Texas, Ecological Service Field Office) to establish guidelines for evaluating the specifics of incidental take for the project, as well as establishing mitigation criteria and long-term protection guidelines for designated miti- gation preserves. The preserves that will be established include nine caves, on 179 acres, each occupied by at least two and up to five of the listed species. This presentation will provide details of preserve establishment, maintenance and monitoring and comments on the distribution and demo- graphic characteristics of some of the listed species.

Introduction This paper provides a brief description of an incidental take permit (Permit No. TE044512- Section 9 of the Endangered Species Act, as 1) and supporting habitat conservation plan for amended, prohibits the “take” of listed wildlife three species of listed karst invertebrates. The species. Take, as defined by the Act, means “to activity requiring the permit is the commercial harass, harm, pursue, hunt, shoot, wound, kill, development (La Cantera) of approximately trap, capture, collect, or to attempt to engage 1,000 acres in Bexar County, Texas, just north- in any such conduct” (Endangered Species Act, west of the City of San Antonio. On December 16 U.S.C. 1531 et seq.). Amendments to the 26, 2000, the U.S. Fish and Wildlife Service Endangered Species Act in 1982 provided pro- published a final rule and determined nine visions in Section 10 that allow for the “inci- cave-dwelling invertebrates from Bexar dental take” of endangered species, by County, Texas, to be endangered species under non-federal entities, as long as the take is inci- the authority of the Endangered Species Act. dental to “otherwise lawful activities.” Sec- These invertebrates are all endemic, obligate tion 10(a)(2)(A) of the Act requires that an troglobites of local distribution in karst terrain applicant for an incidental take permit detail in in Bexar County. The species listed are: a “conservation plan” the impacts that are Rhadine exilis (no common name) and likely to result from the taking and the meas- Rhadine infernalis (no common name), small, ures that will be taken to minimize and mitigate eyeless ground beetles; Batrisodes venyivi for such impacts. The administration of the (Helotes mold beetle) a small, eyeless beetle; Endangered Species Act and responsibility for Texella cokendolpheri (Robber Baron Cave issuing take permits for non-marine wildlife harvestman) a small, eyeless harvestman; species is the responsibility of the United States Cicurina baronia (Robber Baron cave ), Fish and Wildlife Service. Cicurina madla (Madlas cave spider),

116 2001 National Cave and Karst Management Symposium Cicurina venii (no common name), Cicurina sufficient for positive identification has not vespera (Government Canyon Bat Cave spi- been collected, based on the fact that Cicurina der), and Neoleptoneta microps (Government madla has been verified as occurring in two Canyon cave spider), all small, eyeless or essen- caves within two to three miles of La Cantera, tially eyeless spiders (USFWS, 2000a). and no other eyeless Cicurina are known from the University of Texas karst area, this spider Background was assumed, for purposes of the incidental take permit, to be the federally listed species The life history and of the Bexar Cicurina madla (USFWS, 2001). County listed invertebrates is not represented by definitive studies. In 1993, the Service con- La Cantera Caves tracted two studies to summarize the known information on these species. One study fo- Quality of caves on La Cantera cused on the overall karst geography in the San Over 400 potential karst features have been Antonio region and the potential geological evaluated on the property. Three primary geo- and geographical barriers to karst invertebrate logical assessments have been performed in movement and limits to their distribution (Veni the past, and their combined scope has in- and Associates, 1994). The other study summa- cluded the entire property (Raba-Kistner, rized the distribution of the nine invertebrates 1993a and 1993b; SWCA, 2000; Horizon Envi- as understood at that time (Reddell, 1993). ronmental Services Inc., 2000). The karst geography report (Veni and Associ- During extensive karst surveys beginning in ates, 1994) delineates six karst areas or karst 1993 three caves (La Cantera Caves #1, #2, and regions within Bexar County. These regions are #3) containing habitat for the listed karst inver- as follows: Stone Oak, University of Texas at San tebrates were found on the La Cantera prop- Antonio, Helotes, Government Canyon, Culebra erty. Two of these caves (La Cantera Caves #1 Anticline, and Alamo Heights. The boundaries of and #2) are known to contain Rhadine exilis these karst regions are geologic or geographic and Cicurina madla. The entrances to both features that are thought to represent obstruc- caves lie within 200 feet of the west-bound tions to invertebrate movement and which have frontage road of Loop 1604, a heavily traveled resulted in the present-day distribution of inver- highway. Both caves are immediately south tebrates. Whether or not these karst region (approximately 100 feet) of a two-lane road boundaries are truly barriers (past or present) to designed to serve traffic to and from the com- invertebrate distribution is presently uncertain. mercial development. The entrance to La Can- Additional studies are required before the rela- tera Cave #3, which contains Cicurina madla, tionship of invertebrate distribution and karst lies within 100 feet of another internal thor- regions is fully understood. oughfare. Because of the existing disturbances, The La Cantera property is located within the none of the La Cantera caves is considered University of Texas at San Antonio karst region, high-quality habitat for the invertebrates under which is bounded by Helotes Creek to the west, consideration (USFWS, 2000b). The U.S. Fish Leon Creek to the east, and the limits of expo- and Wildlife Service has determined that all sure of the Edwards Group and Glenrose Lime- three La Cantera caves were of medium-quality. stone Formation to the north and south. The None of the listed endangered invertebrates 1993 studies determined that only two of the is known from other karst features present on nine listed species were present in the Univer- the La Cantera property. However, the occur- sity of Texas region, Rhadine exilis and rence of Rhadine exilis, Rhadine infernalis, Rhadine infernalis. Subsequent studies have and/or Cicurina madla (the only known en- also documented occurrence of Cicurina dangered karst species within the University of madla in the region outside the La Cantera Texas karst region), or any of the other listed property (USFWS, 2000a). Biota surveys con- invertebrates elsewhere on the property can- ducted by SWCA in 1994, 1995, and 2000 in not conclusively be ruled out given the poten- three La Cantera caves resulted in discovery of tial for these species to occur in subsurface eyeless Cicurina spiders and Rhadine exilis, voids lacking obvious surface expression (Veni but no Rhadine infernalis. Based on the best and Associates, 1994). available scientific information, the Cicurina spider found on the La Cantera property is Karst Invertebrate Preserve most likely the listed Cicurina madla. It is Guidelines possible that this spider is an undescribed spe- cies of Cicurina (Cokendolpher, pers comm). In an effort to provide guidelines for the Although an adult La Cantera eyeless spider protection of endangered karst invertebrates,

2001 National Cave and Karst Management Symposium 117 the U.S. Fish and Wildlife Service has deter- tera Cave #2 – Helotes Hilltop, Helotes Blow- mined that the minimum total area needed to hole, Madlas Cave, and John Wagner Ranch protect caves or cave clusters containing karst Cave #3 (approximately 34 acres, five listed invertebrates is 69 to 99 acres (USFWS, 2000b). species, four medium-quality caves); La Can- Further, the agency suggests that an area within tera Cave #3 – Canyon Ranch Pit, (approxi- that area a minimum 100- to 200-meter (328- to mately 75 acres, five listed species, three 656-foot) radius from all karst features contain- high-quality caves). ing listed invertebrates should be preserved. This In addition to providing 181 acres of cave includes a core area encompassing the minimum preserves, the La Cantera habitat conservation 50-meter (164-foot) cave cricket foraging range plan also provides for participation with the and an additional buffer against edge effects. U.S. Fish and Wildlife Service in the develop- Also, since roads may hinder movement of sev- ment of an outreach program, and provides for eral species of invertebrates and small mammals, a $20,000 grant to support DNA research of no internal roads or other permanent habitat Cicurina taxonomy. The outreach program has fragmentation should occur within the protected the goal of raising awareness, understanding, area. It is the current policy of the U.S. Fish and and appreciation for Bexar County endangered Wildlife Service that disturbances that approach karst invertebrates. Under this program infor- closer than the standards detailed above, are mation materials will be produced by public likely to constitute take. relations professionals and will be designed to reach the broadest possible audience (includ- La Cantera Habitat Conservation Plan ing school children, landowners, and the pub- lic at large). The intent of these materials will On-site and Off-site Preserves. be to impress upon the audience the impor- As part of the habitat conservation plan’s tance of preserving the threatened karst re- development, La Cantera will assure that seven sources and their invertebrate inhabitants. karst preserves totaling approximately These materials will be designed to render 181 acres will be protected in perpetuity by technical information relating to karst habitats appropriate legal mechanisms (conservation and their inhabitants in non-technical terms easements, deed restrictions) before clearing and graphics. or construction begins on undeveloped por- tions of the property. The karst preserves in- U.S. Fish and Wildlife Service Assess- clude one-acre on-site preserves for La Cantera ment of Development Impacts to Caves #1 and #2, and five off-site preserves Listed Species totaling approximately 179 acres. These off-site preserves include: an approximately five-acre It is the U.S. Fish and Wildlife Service’s opin- area encompassing Madlas Cave; an approxi- ion that take of Rhadine exilis will occur in La mately four-acre area encompassing John Wag- Cantera Caves #1 and #2, and take of Cicurina ner Ranch Cave #3; approximately 70 acres madla will occur in all three La Cantera caves, encompassing Hills and Dales Pit; approximately as a result of the development and occupation 25 acres encompassing Helotes Hilltop and of the La Cantera property. Although the Fish Helotes Blowhole Caves; and approximately 75 and Wildlife Service recognizes that the existing acres encompassing Scenic Overlook, Canyon quality of endangered species habitat presently Ranch Pit, and Fat Mans Nightmare Caves. All of provided by the three La Cantera caves is not the off-site caves within the proposed karst pre- optimal, development of the property would serves contain endangered karst invertebrate likely reduce the amount of such habitat pre- species as well as other cave-adapted species. A sent in the project region. Take of endangered summary of endangered invertebrate species karst invertebrates could also occur elsewhere known from each of the proposed on- and off-site on the property in the event previously undis- preserve caves is provided in Table 1. covered habitat is encountered. Although no The U.S. Fish and Wildlife Service consid- endangered karst invertebrates are known to ered the La Cantera caves to be of medium occur on the property in areas outside of the quality with regard to habitat for listed inverte- three La Cantera caves, potential exists for brates. For each of these caves, the habitat listed species to be present in subsurface void conservation plan provides for mitigation by spaces lacking obvious surface expression. preserving caves of similar or higher quality. Such spaces could be destroyed or significantly For each La Cantera cave, the following mitiga- disturbed by construction activities. As all por- tion has been provided: La Cantera Cave #1 – tions of the property outside of the two pro- Hills & Dales Pit (approximately 70 acres, four posed on-site karst preserves (at La Cantera listed species, one high-quality cave); La Can- Caves #1 and #2) are expected to be devel-

118 2001 National Cave and Karst Management Symposium oped, any endangered karst invertebrates oc- two species (which is not certain), sufficient curring on the property outside of these pre- habitat will likely remain within the University serves are expected to be taken by completion of Texas karst region to provide necessary con- of the development; however, such take will be servation. Within the University of Texas karst fully mitigated for through the conditions de- region, two suitable preserves are now inhabited tailed in the habitat conservation plan. Due to by Cicurina madla. Future exploration of Mas- the extensive karst surveys of the property, the todon Pit (less than 0.5 mile south of the prop- likelihood of discovering previously unde- erty) will probably also yield this species. tected habitat is considered low. Moreover, extensive conservation of known, oc- Protecting La Cantera Caves #1 and #2 within cupied Cicurina madla habitat is provided out- one-acre preserves will significantly reduce the side the University of Texas karst region. The U.S. risk of disturbing karst invertebrate habitat dur- Fish and Wildlife Service believes that strict ad- ing construction. The U.S. Fish and Wildlife Serv- herence to the “three occupied caves per spe- ice, however, believes that reduction of native cies” rule may not be biologically required to vegetation to one-acre patches surrounding ensure conservation of a species where the spe- these caves will reduce the amount of nutrients cies’ range includes several karst regions. Such is entering these features, the amount of organic the case for Cicurina madla. One of the present material available to be washed into the features, anomalies of the karst region configuration as and the amount of habitat supporting cave crick- currently proposed (Veni and Associates, 1994) ets and other trogloxene species. According to is the fact that Cicurina madla occurs in four of the U.S. Fish and Wildlife Service, increased in- the six karst regions. The presence of this single tensity of fire ant infestations within the karst taxa in multiple karst regions may call into ques- preserves and/or introduction of other exotic tion the hypothesis of geologic or geographic species that could be detrimental to the karst features obstructing invertebrate movement be- ecosystem may also result from clearing, con- tween karst regions. struction, and development activities. Due to Within the University of Texas at San Antonio cave depth (roughly 60 to 115 feet) and existing karst region, at least five caves are known to be edge along the nearby Loop 1604 right-of-way, inhabited by Rhadine exilis. For Cicurina potential preserve edge effects (such as increased madla, positive identifications have been drying of woodland, with concomitant drying of made in two large cave preserves (Hills and cave habitat, and increased temperature fluctua- Dales Pit and Robbers Cave), and another four tions) are expected to be negligible. While pro- caves have produced eyeless Cicurina thought posed development may not result in to be Cicurina madla, though positive identi- elimination of Rhadine exilis and Cicurina fication requires further study. madla from these two caves, it is anticipated that Other University of Texas at San Antonio karst numbers of these two species within these caves region caves known to have eyeless Cicurina will be reduced over time. (To put the existing spiders that are most likely Cicurina madla in- density of invertebrates in perspective, the clude: Mastodon Pit, Kamakazi Cricket, John authors have visited Caves #1 and #2 approxi- Wagner Ranch Cave #3, and Three-fingers Cave. mately four times in nine years searching for karst Outside the University of Texas at San Antonio invertebrates for a period of two hours per visit karst region, Cicurina madla is known to occur and have found an approximate total of five to in Christmas Cave, Madlas Cave, Madlas Drop six R. exilis and 20 to 30 eyeless Cicurina.) A Cave, and Helotes Blowhole Cave in the Helotes monitoring program included in the habitat con- karst region; Lost Pothole Cave in the Govern- servation plan will provide long-term data on the ment Canyon karst region; and Headquarters accuracy of these predictions. Cave in the Stone Oak karst region. Of these The U.S. Fish and Wildlife Service believes known localities, at least four sites are either in that the overall impact to Rhadine exilis and preserves now (Lost Pothole Cave, Headquarters Cicurina madla resulting from development Cave) or will be preserves as a result of the La of the La Cantera property will neither prevent Cantera habitat conservation plan (Madlas Cave, nor seriously impact the long-term conserva- Helotes Blowhole Cave). Thus, actions effected tion of each species within the University of as a result of the La Cantera permit are not likely Texas at San Antonio karst region. The U.S. Fish to preclude the long-term conservation of either and Wildlife Service desires that a minimum of Rhadine exilis or Cicurina madla. three karst preserves for each species within Because the habitat conservation plan each karst region be set aside to provide for would protect approximately 181 acres of on- long-term conservation of karst invertebrates and off-site land, the U.S. Fish and Wildlife (USFWS, 1994). Assuming development of the Service has determined that the project is ex- property will preclude on-site survival of the pected to provide an overall benefit to Bexar

2001 National Cave and Karst Management Symposium 119 County endangered karst invertebrates. The ing the nine listed Bexar County karst inverte- identification of species, evaluation of take, and brates. We anticipate that many more will fol- design and configuration of the karst preserves low, and that the La Cantera permit will serve are based on the best scientific information as a model for future permits. We believe that available. Protecting off-site karst ecosystems as the La Cantera habitat conservation plan will provided in the habitat conservation plan provide significant conservation opportunities would represent a major recovery action for for the subject invertebrates. We are con- other listed species besides Rhadine exilis, and cerned, however, that the existing U.S. Fish and Cicurina madla, particularly Rhadine infer- Wildlife Service standard of requiring 69 to 99 nalis, Batrisodesvenyivi, and Texella coken- acres of habitat per cave or cave cluster could dolpheri, and the undescribed Texella new prove to be counterproductive to efforts to species and Neoleptoneta new species. preserve cave habitat. We believe there are presently insufficient data to validate the need Summary and Conclusion for these relatively large preserves. While it is the responsibility of the U.S. Fish This document has summarized the condi- and Wildlife Service to err on the side of the tions of the first incidental take permit involv- species, smaller preserves may, in fact, provide

Table 1. Summary of Endangered Species Known to Occur in the La Cantera On-site and Off-site Preserve Caves. Preserve Cave Karst Region Endangered Species Other Rare Karst Present Species Present La Cantera Cave #1 University of Texas at Rhadine exilis eyless Cicurina sp. San Antonio (probably C. madla) La Canter Cave #2 University of Texas at Rhadine exilis eyless Cicurina sp. San Antonio (probably C. madla) Hills and Dales Pit University of Texas at Rhadine exilis Neoleptoneta new sp. San Antonio Cicurina madla Texella sp. (possibly T. cokendolpheri) John Wagner Ranch University of Texas at Rhadine exilis (type Neoleptoneta new sp. Cave #3 San Antonio location) eyless Cicurina sp. Rhadine infernalis (probably C. madla) Texella cokendolpheri Helotes Blowhole Cave Helotes Rhadine exilis Rhadine infernalis Cicurina madla Helotes Hilltop Cave Helotes Rhadine exilis eyless Cicurina sp. Batrisodes venyivi (probably C. madla) (type location) Madlas Cave Helotes Rhadine infernalis (type location) Cicurina madla Canyon Ranch Pit Government Canyon Rhadine infernalis eyless Cicurina sp. (probably C. madla) Fat Mans Nightmare Government Canyon Rhadine infernalis eyless Cicurina sp. Cave (probably C. madla) Texella sp. (possibly T. cokendolpheri) Scenic Over Look Cave Government Canyon Rhadine infernalis eyless Cicurina sp. Batrisodes venyivi (probably C. madla) (third known Texella sp. location) (possibly T. cokendolpheri)

120 2001 National Cave and Karst Management Symposium the same measure of protection for these tro- WCA, Inc. 2000. Results of karst terrain features globitic organisms. It is important, therefore, investigations of the La Cantera property that relevant research be focused on this issue northern Bexar County, Texas. An unpub- as soon as possible. Landowners may be far lished report prepared for the La Cantera more willing to provide a five- to ten-acre buffer Development Company. around significant karst features and our fear is that the 69- to 99-acre requirement will result U.S. Fish and Wildlife Service. 1994. Recovery indestruction of the vary resource we are trying plan for endangered karst invertebrate in to protect. Travis and Williamson counties, Texas:U.S. Fish and Wildlife Service Region 2. 154 p. References Cited U.S. Fish and Wildlife Service. 2000a. Endan- Cokendolpher, J. C. 2000. Personal communi- gered and threatened wildlife and plants; cation during the development of the La final rule to list nine Bexar County, Texas Cantera habitat conservation plan. invertebrate species as endangered. Horizon Environmental Services, Inc. 2000. U.S. Fish and Wildlife Service. 2000b. Draft U.S. Karst investigation 136-acre La Cantera retail Fish and Wildlife Service recommendations property at Loop 1604 and La Cantera Boule- for karst preserve design. Version May 18, vard San Antonio, Bexar County Texas.Un- 2000. published report prepared for The Rouse Company, Columbia, Maryland. U.S. Fish and Wildlife Service. 2001.Environ- mental Assessment for Issuance of two En- Raba-Kistner Consultants, Inc. 1993a. Geologic dangered Species Act Section 10(a)(1)(B) assessment for water pollution abatement Permits for the Incidental Take of a Troglo- plan, La Cantera Village, San Antonio, Texas. bitic Ground Beetle (Rhadine exilis) and Unpublished report for Pape-Dawson Engi- Madlas Cave Meshweaver (Cicurina madla) neers. During the Construction and Operation of Commercial Development on the Approxi- Raba-Kistner Consultants, Inc. 1993b. Geologic mately 1,000-Acre La Cantera Property, San assessment for water pollution abatement Antonio, Bexar County, Texas. March 9, plan, La Cantera Retail Center, San Antonio, 2001. Texas. Unpublished report for Pape-Dawson Engineers. Veni and Associates. 1994. Geologic controls on cave development and the distribution of Reddell, J.R. 1993. The status and range of endemic cave fauna in the San Antonio, endemic from caves in Bexar Texas, Region. Prepared for Texas Parks and County, Texas. A report to the U.S. Fish and Wildlife Department and the U.S. Fish and Wildlife Service and the Texas Parks and Wildlife Service. Wildlife Department.

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