Determining the baseline status of Black-capped Vireos in Texas

Groce, Julie; Texas A&M University; Morrison, Michael

The purpose of this project was to determine the distribution and abundance of the Black-capped Vireo (Vireo atricapilla) (BCVI), an endangered species, throughout its breeding range in central Texas. Researchers plan to develop a BCVI occupancy model. In spring 2009, researchers surveyed more than 4000 points throughout the breeding range on public and private properties in an effort to estimate more accurately the current BCVI distribution and abundance. This will allow for a better understanding of the trends in rangewide populations over time. This report outlines methods and results for data collected in Big Bend National Park in 2009. Researchers conducted 179 5-minute point surveys and recorded location data for 20 BCVI. Data were collected by two observers independently. Researchers collected vegetation information at 45 survey points and 14 BCVI locations. All statewide data will be analyzed throughout the 2009-2010 winter and a preliminary habitat model will be developed. Field work in 2010 will involve additional surveys throughout central and west Texas and model validation.