Bexar County Karst Invertebrates Draft Recovery Plan March 2008 Bexar County Karst Invertebrates Draft Recovery Plan BEXAR COUNTY KARST INVERTEBRATES DRAFT RECOVERY PLAN Southwest Region U.S. Fish and Wildlife Service Albuquerque, New Mexico March 2008 Approved: ___DRAFT_______________________________________ Regional Director, Southwest Region Date U.S. Fish and Wildlife Service Concur: __DRAFT____________________________________________ Executive Director Date Texas Parks and Wildlife Department ii Bexar County Karst Invertebrates Draft Recovery Plan DISCLAIMER Recovery plans delineate reasonable actions that the best available science indicates are necessary to recover or protect listed species. Plans are published by the U.S. Fish and Wildlife Service (Service), but are sometimes prepared with the assistance of recovery teams, contractors, state agencies, and others. Objectives will be attained and any necessary funds made available subject to budgetary and other constraints affecting the parties involved, as well as the need to address other priorities. Recovery plans are guidance and planning documents only. Identification of an action to be implemented by any private or public party does not create a legal obligation beyond existing legal requirements. Nothing in this plan should be construed as a commitment or requirement that any Federal agency obligate or pay funds in contravention of the Anti-Deficiency Act (U.S.C. 1341) or any other law or regulation. Recovery plans do not necessarily represent the views or the official positions or approval of any individuals or agencies involved in the plan formulation, other than the Service. They represent the official position of the Service only after the plan has been signed by the Regional Director as approved. Approved recovery plans are subject to modification as dictated by new information, changes in species status, and the completion of recovery actions. Please check for updates or revisions at the website below before using. Literature citation should read as follows: U.S. Fish and Wildlife Service. 2008. Bexar County Karst Invertebrates Draft Recovery Plan. U.S. Fish and Wildlife Service, Albuquerque, NM. Additional copies may be obtained from: U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service Austin Ecological Services Office Southwest Regional Office 10711 Burnet Road, Suite 200 500 Gold Street, SW Austin, TX 78758 Albuquerque, NM 87102 Tel. #512-490-0057 Or on line at: http://www.fws.gov/endangered iii Bexar County Karst Invertebrates Draft Recovery Plan ACKNOWLEDGMENTS The Service gratefully acknowledges the commitment, dedication, and efforts of the Karst Invertebrate Recovery Team in the preparation of this recovery plan (list on p. v). Without their valuable expertise and assistance, this recovery plan would not have been possible. We would especially like to thank Dr. Jean Krejca and Dr. Steve Taylor at the University of Illinois for drafting the recovery plan. Additional thanks go to Cyndee Watson and Alisa Shull (in the Service‟s Austin Ecological Services Field Office) for their recovery planning expertise and editing of this document. The biology, threats, and conservation needs of these species and the karst ecosystems they occur in are very similar to congeners that occur in nearby Travis and Williamson counties, Texas. Literature on the Travis and Williamson county species, including the recovery plan for those species (Service 1994), was used extensively during the creation of this document, and we thank those authors. Other reports prepared by and for the Service relating to Bexar County karst invertebrates also provided significant material for this plan (Service 2003, Veni 2003). The Service would also like to express its appreciation for the many individuals, groups, and agencies actively involved in the recovery of the federally endangered karst invertebrate species of Bexar County. We look forward to continued collaboration with these partners and new partners to conserve these species and the ecosystem on which they depend. Additional contributors include Dr. Andrew G. Gluesenkamp, Christine L. Krejca, and G. Rob Myers, III. iv Bexar County Karst Invertebrates Draft Recovery Plan KARST INVERTEBRATE RECOVERY TEAM Technical Subcommittee Dr. Dave Culver Dr. Rich Patrock Department of Biology Section of Integrative Biology American University University of Texas at Austin Nico Hauwert James Reddell City of Austin Texas Memorial Museum Watershed Department Dr. Jean Krejca Dr. Steve Taylor, Subcommittee Chair Zara Environmental LLC Illinois Natural History Survey Dr. David Diamond Dr. George Veni Missouri Research Assessment National Cave and Karst Research Institute Mike Quinn Dr. David Ribble Texas Parks and Wildlife Department Trinity University Implementation Subcommittee Susan Spegar Linda Palit City of San Antonio Texas Cave Management Association Gene Dawson, Subcommittee Jackie Schlatter Chair Camp Bullis Pape-Dawson Engineering Department of Defense Allison Elder Lee Sherrod Bexar Land Trust Horizon Environmental Services, Inc. George Kegley Texas Parks and Wildlife Department (retired) Recovery Team Consultants Dr. James Cokendolpher Peter Sprouse Biologist Zara Environmental LLC Kurt Helf Dr. Kemble White Mammoth Cave National Park SWCA, Inc. Dr. Francis Howarth Dr. Rick Olson Bishop Museum Mammoth Cave National Park Cyndee Watson - U.S. Fish and Wildlife Service Liaison to Recovery Team v Bexar County Karst Invertebrates Draft Recovery Plan EXECUTIVE SUMMARY Species Status - Nine Bexar County karst invertebrates were listed as endangered species on 26 December 2000 (65 FR 81419). These species inhabit caves and mesocaverns (humanly impassable voids in karst limestone) in Bexar County, Texas. Rhadine exilis is known from 45 caves, Rhadine infernalis is known from 26 caves, Batrisodes venyivi is known from two caves, Texella cokendolpheri is known from one cave, Neoleptoneta microps is known from two caves, Cicurina baronia is known from one cave, Cicurina madla is confirmed (based on morphological taxonomic characteristics) from eight caves, Cicurina venii is known from one cave, and Cicurina vespera is known from two caves. All species have a recovery priority of 2c1, and critical habitat was designated on 8 April 2003 for all of the species, except the Government Canyon Bat Cave spider and meshweaver. The current status of the species in most of these cave sites is not known, however at least some of the sites are lacking a sufficiently large, healthy, and native surface plant and animal community deemed necessary for long-term support of a cave community. Habitat Requirements and Limiting Factors - All of these invertebrates are troglobites, spending their entire lives underground. They are characterized by small or absent eyes and pale coloration. Their habitat includes caves and mesocavernous voids in karst limestone (a terrain characterized by landforms and subsurface features, such as sinkholes and caves, which are produced by solution of bedrock). Karst areas commonly have few surface streams; most water moves through cavities underground. Within this habitat these animals depend on high humidity, stable temperatures, and nutrients derived from the surface. Examples of nutrient sources include leaf litter fallen or washed in, animal droppings, and animal carcasses. It is imperative to consider that while these species spend their entire lives underground; their ecosystem is very dependent on the overlying surface habitat. The primary threat to these species is habitat loss. Caves and karst habitat are lost directly by being completely filled in during development, or by quarrying away the rock that they are comprised of. Filling in cave entrances or severely altering entrances is also destructive and may result in habitat loss. Caves and karst may be lost indirectly by degrading the habitat to the point that the cave and karst can no longer support the species or the long term viability of the population is reduced. Examples of this habitat degradation include: altering drainage patterns, altering native surface plant and animal communities, reducing or increasing nutrient flow, contamination, excessive human visitation, and competition and predation from non-native, invasive species. Recovery Strategy - The recovery strategy is to reduce threats to the species by securing an adequate quantity and quality of caves. This includes selecting caves or cave clusters that represent the range of the species and potential genetic diversity for the nine species, then preserving these caves, including their drainage basins and surface communities upon which they rely. Maintenance of these cave preserves involves keeping them free 1Recovery priority 2c indicates that these species face a high degree of threat with a high potential for recovery and there may be conflict between species recovery and economic development. vi Bexar County Karst Invertebrates Draft Recovery Plan from contamination, excessive human visitation, and non-native fire ants by regularly tracking progress and implementing adaptive management to control these and any new threats when necessary. Monitoring the population status and threats are also components of recovery. Because many aspects of the population dynamics and habitat requirements of the species are poorly understood, recovery is also dependant on incorporating research findings into adaptive management actions. Since four of these species are known to occur in only one cave, full recovery