Final Lower Rio Grande Valley and Santa Ana National Wildlife Refuges Comprehensive Conservation Plan September 1997 (Reprint March 1999) U.S. Fish and Wildlife Service U.S. Department of the Interior Cover Artwork by Brian Cobble Table of Contents VISION........................................................................................................................................... 5 Executive Summary................................................................................................................... 6 1.0 Introduction and Regional Setting................................................................................. 8 1.1 LRGV Challenges............................................................................................... 8 2.0 Planning Perspectives and Considerations................................................................ 9 2.1 National Wildlife Refuge System ................................................................... 9 2.2 The Service & Ecosystem Management ...................................................... 9 2.3 Refuge Complex and Management Districts........................................... 10 2.4 Laguna Atascosa NWR -- A Partner with LRGV NWR............................ 10 2.5 Planning Perspectives.................................................................................... 10 2.6 The Issues.......................................................................................................... 11 2.7 The Need for Action......................................................................................... 11 2.8 Expected Planning Outcomes ...................................................................... 12 2.9 Public Involvement .......................................................................................... 13 3.0 Ecosystem and Refuge Resource Description......................................................... 13 3.1 LRGV Area of Ecological Concern General Description....................... 14 3.2. Biotic Communities Designations for Land Acquisition....................... 14 3.3 Wildlife ................................................................................................................ 24 3.4 Climate ................................................................................................................ 25 3.5 Geology............................................................................................................... 26 3.6 Soils..................................................................................................................... 26 3.7 Water Development, Flood Control, and International Boundary Stabilization....................................................................................................... 27 3.8 LRGV Socio-economic Features.................................................................. 30 3.9 Refuge Staffing Needs.................................................................................... 31 4.0 Legal, Policy, and Administrative Guidelines, and Other Special Considerations ............................................................................................................. 33 4.1 Legal Mandates................................................................................................. 33 4.2 Agency-Wide Policy Directions.................................................................... 40 Fish and Wildlife Service Agency Mission................................................ 40 Refuge System: Mission and Goals............................................................ 41 4.3 Refuge Purpose Statements ......................................................................... 42 LRGV NWR Purpose........................................................................................ 42 Santa Ana NWR Purpose ............................................................................... 42 5.0 Lower Rio Grande Valley NWR Management Program.......................................... 42 5.1 Biological Diversity, Land Protection, and Wildlife and Habitat Management ...................................................................................................... 43 A. Acquisition and Land Status Objectives............................................. 43 B. Research Objectives................................................................................. 44 C. Endangered Species Objectives............................................................ 45 D. Revegetation and Habitat Management Objectives ......................... 46 E. Fire Management........................................................................................ 48 F. Law Enforcement ....................................................................................... 49 G. Partnerships and Cooperative Efforts ................................................. 49 5.2 Water Rights, Water Management and the Management of Wetlands ............................................................................................................................... 50 5.3 Water Quality and Contaminants................................................................. 53 5.4 Cultural Resources.......................................................................................... 54 5.5 Public Use, Recreation, and Wildlife Interpretation & Education ....... 55 6.0 Santa Ana NWR Management Program...................................................................... 57 6.1 Biological Diversity, Land Protection, and Wildlife and Habitat Management ...................................................................................................... 57 A. Acquisition and Land Status Objectives............................................. 57 B. Scientific Data Objectives ....................................................................... 57 C. Endangered Species Objectives............................................................ 58 D. Revegetation and Habitat Management Objectives ......................... 58 E. Fire Management........................................................................................ 58 F. Law Enforcement ....................................................................................... 59 G. Partnerships and Cooperative Efforts ................................................. 59 6.2 Water Rights, Water Management and the Management of Wetlands ............................................................................................................................... 59 6.3 Water Quality and Contaminants................................................................. 60 6.4 Cultural Resources.......................................................................................... 61 6.5 Public Use, Recreation, and Wildlife Interpretation & Education ....... 61 7.0 Refuge Management Strategies by District............................................................... 63 7.1 Starr County District Strategies................................................................... 63 7.2 Southern Hidalgo District Strategies.......................................................... 64 Santa Ana NWR Specific Strategies ........................................................... 65 7.3 Cameron County District Strategies........................................................... 69 7.4 Upper Hidalgo and Willacy County District Strategies.......................... 70 Appendix .................................................................................................................................... 72 Butterflies of the LRGV/Santa Ana NWR Complex ............................................. 73 Fishes of the LRGV/Santa Ana NWR Complex .................................................... 81 Amphibians of LRGV NWR / Santa Ana NWR Complex .................................... 83 Reptiles of LRGV NWR / Santa Ana NWR Complex............................................ 84 Birds of the LRGV/ Santa Ana NWR Complex...................................................... 86 Mammals of The LRGV/ Santa Ana NWR Complex ........................................... 98 Plant Species List .......................................................................................................... 101 FEDERAL LISTING BY COUNTY ........................................................................................ 119 Bibliography ............................................................................................................................ 120 MAPS.......................................................................................................................................... 124 VISION Few wild places in the Western Hemisphere exhibit such a diversity of flora, fauna and geomorphic conditions as the lower Rio Grande Valley in south Texas. Its remnant natural habitats thrive along side social and economic activities. This can be a great advantage over the next twenty years if conservation and development activities are well coordinated. Still, few wild places have the opportunity for recovery from the brink of extinction. The Lower Rio Grande Valley and Santa Ana National Wildlife Refuges include some of the last parcels of subtropical thorn forests in the U.S. and they represent the best chance for their protection and recovery. Ultimately, they will help form a functioning corridor to sustain the unique flora and fauna of the Texas/Mexico border. The Lower Rio Grande Valley Refuge will someday be 132,500 acres of mostly contiguous tracts