Population Trends of Breeding Birds on the Edwards Plateau, Texas: Local Versus Regional Patterns (Report‪)‬

Fort Hood Military Reservation, located on the Edwards Plateau in central Texas, has been designated a globally important bird area by the American Bird Conservancy because of substantial populations of two endangered songbirds, the black-capped vireo (Vireo atricapilla) and the golden-checked warbler (Dendroica chrysoparia; Anders and Dearborn, 2004; Cimprich and Kostecke, 2006). However, with the exception of these two species, status of avian populations on Fort Hood has not been assessed. I use population-trend data generated from point counts conducted over 10-years to assess status of 32 common species that breed within wooded habitats (i.e., shrublands and woodlands) on Fort Hood. Further, I compare trend data for Fort Hood with trend data for the same species and time period generated by the Breeding Bird Survey (Sauer et al., 2005) for the Edwards Plateau because cross-scale comparisons can provide insight into generality and causality of trends (Holmes and Sherry, 1988, 2001; Ballard et al., 2003). MATERIALS AND METHODS--Study Area--The Edwards Plateau covers ca. 9,500,000 ha of Texas (The Nature Conservancy, 2004). Habitat is a mosaic of grasslands and woodlands. From east to west, there is a shift from juniper-oak (Juniperus ashei-Quercus) wooded canyon-lands to xeric shrublands. Livestock grazing is the primary land use on the Edwards Plateau (The Nature Conservancy, 2004). Parts of the eastern Edwards Plateau are under intense development pressure (e.g., Austin and San Antonio).