TEXAS GEMS -ARANSAS NATIONAL WILDLIFE REFUGE (ANWR)
Established in 1937, ANWR encompasses 58,982 acres. It is divided into the Blackjack Peninsula (47,261 ac.), the Tatton Unit (7,568 ac.), the Lamar Unit (733 ac.), and the Myrtle Foster Whitmire Division (3,420 ac.). ANWR is a coastal waterfowl refuge and a wintering grounds for the only naturally migrating and breeding population of the Whooping Cranes (Grus americana). It is located approximately 60 miles northeast of Corpus Christi, Texas. Approximately 80,000 people visit the refuge each year, most of whom arrive seeking the abundant bird species for which the refuge is so well known. The national Wildlife preserve is located in Aransas, Refugio, and Calhoun counties.
Area of Influence:
Watershed 12100405- Aransas Bay . Watershed 12100404- West San Antonio & Hynes bays (USGS Hydrologic Units, Texas Maps). Gulf Coast Prairies and Marshes-4b- Estuarine Zone and 4c- , Upland Prairies and Woods (Ecoregions and Sub-regions, Texas Maps).
ANWR falls under the Gulf Prairies and Marshes which is broken down into:1) Bluestem Grassland, 2) Live Oak Woods/Parks, and 3) Marsh/Barrier Island. Grassland, live oak, and redbay thickets cover most of the uplands creating an island of habitat surrounded by thousands of acres of agricultural lands to the north and west, and saltwater bays to the south and east. The peninsula is ringed by tidal marshes and uplands are broken by long, narrow swales that are often flooded.
ANWR is a federally designated critical habitat for the Whooping Crane, one of the endangered/threatened species best known in the refuge. Others include the Southern Bald Eagle, the Brown Pelican, and the Piping Plover. The last confirmed nest of an Attwater's Greater Prairie- chicken on the Refuge was in 1982 and the last documented sighting was in the early 1990's. The endangered Eskimo Curlew has been sighted twice on the refuge, in 1950 and again in 1987. Rare/endangered/threatened species and natural communities with occurrence record on the refuge include:
Whooping Crane (Grus americana)
Jaguarundi (Felis yaguarondi)
Scarlet Snake (Cemophora coccina lineri)
Gulf Saltmarsh Snake (Nerodia clarkii)
Coastal gay-feather (Liatris bracteata)
Threeflower broomweed (Thurovia triflora)
ANWR has 93 species of birds documented as having nested on the refuge. Approximately 28 species of mammals have resident breeding populations. American Alligator nests have been found near most bodies of freshwater on the refuge. This species is just one of the large number of reptiles and amphibians that live and breed on ANWR. Sixty species of fish are on the refuge checklist of common fish. Many saltwater species come into the shallows seasonally as juveniles and return to the Gulf as adults. Others enter the surrounding grass beds on a flood tide seeking food, then leave on the ebb tide. Freshwater and brackish-water tolerant species inhabit the ponds and sloughs found on the refuge.
The habitat types on the ANWR, which can be broken down into as many as 12 biotic communities, provide a diverse array of feeding areas for the wildlife that inhabit and visit the refuge. The grasslands and marshes on the refuge provide an area for birds and mammals to feed on a huge variety of aquatic and terrestrial invertebrates and plant species. The wooded uplands are used to forage for acorns, berries, and other nutritious plant species.
ANWR provides a stopover and wintering area for more than 210 species of birds migrating in either the spring or fall, or both seasons. The length of stopovers by migratory birds varies widely, depending on the species. Four species of migratory bats also have been recorded on the refuge.
The Blackjack Peninsula (the name is coined from its scattered blackjack oaks) of the ANWR is a relict portion of a Pleistocene sandbar known as the Ingelside Barrier. This peninsula is a thumb of land pointing southwest. To the west is St. Charles Bay separating it from the mainland. On the east the peninsula is protected from the Gulf by sandbar islands of St. Joseph and Matagorda. The Blackjack Peninsula is primarily sand, while the Tatton Unit is composed of loamy clay soils.
ANWR serves as a forage and breeding ground for hundreds of animal species. It also serves as a water filter and water quality controller through its grass beds.
Uniqueness of Natural Community:
The ANWR is special because it hosts the wintering population of the endangered Whooping Crane, but the refuge also hosts a diverse and flourishing population of other wildlife species. Records list 392 bird species and 39 mammal species as having occurred on the refuge. Sixty species of fish are listed on the refuge checklist as common, and the checklist for amphibians and reptiles lists 63species. The refuge currently lists about 850 plant species, and it is continually being adjusted and expanded. The ANWR is part of the Texas Coastal Bend, which forms a transition zone between the upper and lower Gulf Prairies. The ANWR serves as the southern limit or the northern limitof many species found in Texas. The refuge's proximity to the Gulf Coast and its diverse habitats contribute to its attractiveness to many migratory birds.
Archaeological and Cultural Significance:
There are no known archeological or culturally significant sites on the preserve, but a detailed survey for such resources has not been conducted.
The refuge offers wildlife observation and photography, and seasonal hunting and fishing access. Visitors may use a tour route for automobiles and bicycles, a picnic area, a 40-foot observation tower, hiking trails, and a handicap access trail.
Petroleum was discovered at the refuge in 1939. It was not until 1947 that continuous production of petroleum and gas took place. Refuge and petroleum officials and oil men have been working together in an atmosphere of cooperation and understanding to ensure maximum protection for the wildlife and its habitat, and to preserve the natural beauty of the refuge. Natural gas production is still ongoing on the refuge.
The ANWR is owned by the U.S. Department of Interior, Fish and Wildlife Service.
The ANWR is administered as a national wildlife refuge by the U.S. Fish and Wildlife Service.
Many of the refuge's resources are dedicated to the recovery of the Whooping Crane and the management of its habitat. Other management efforts are in public education and interpretation, and in the enhancement of the wildlife resource, primarily through prescribed burns.
Existing Monitoring Activities:
Whooping Crane monitoringChristmas count of bird species on the refugeButterfly count
More research and habitat restoration is the number one need for ANWR.
Threats to Ecological Integrity:
The Gulf Intracoastal Waterway (GIWW) threatens the critical habitat of the Whopping Crane through increased shoreline erosion and the potential of hazardous cargo spills. Disposal of the potentially toxic soil when the GIWW is dredged, also represents a threat to the ecological integrity of the tidal marshes. Whooping Crane habitat is also threatened by naturally occurring hurricanes. The urgency of these threats is small.
Cooperative efforts have led to cement mats to slow erosion along the GIWW. The ANWR has an action plan for spills.
Source of Information
McAlister, W. H. 1995. A Naturalists Guide : Aransas. University of Texas Press, Austin, Texas.