From the snaking riparian areas of the Rio Grande, to the arid lowlands of the Chihuahuan Desert and the high elevation forests of the Chisos Mountains, Big Bend National Park is home to a unique assortment of mammalian life, including 22 species of bats that take full advantage of the habitat gradient (Ammerman et al. 2012).
Twenty-five years after Easterla’s initial surveys, Dr. Loren Ammerman of Angelo State University also took an interest in the bats of Texas and the Big Bend region. As a result, Ammerman has led annual excursions, spanning all months, to Big Bend National Park with the objective of expanding upon our general knowledge of bats, their genetics, roosting ecology, and diet since 1996.
Analysis of data collected from 1996 to 2013 demonstrates an extensive survey effort by Ammerman and her students, whom at that point had captured approximately 5,700 bats of 21 species over 258 nights and across 31 survey sites in Big Bend National Park and 10 sites outside of park boundaries (Ammerman and Adams). When supplemented with the initial species diversity logged by Easterla, the number of bats known to occur in the park was officially raised from 18 to 22 species, just 5 shy of the total 27 species found within the greater Chihuahuan Desert region (Ammerman et al. 2012). Species that were reported in the park for the first time by Ammerman and her team include the Western Yellow Bat (Lasiurus xanthinus), the Silver Haired Bat (Lasionycteris noctivagans), and the Tri-colored Bat (Perimyotis subflavus). A full list of bat species documented within the park can be found in the Mammal Checklist (Big Bend National History Association 2019).
The fungus, Pseudogymnoascus destructans, known to cause WNS was detected in Texas for the first time in early 2017 within 6 counties in the Texas panhandle (Texas Parks and Wildlife Department 2017). Since initial discovery, the fungus has now been detected in 21 counties and on four species including the Cave Myotis (Myotis velifer), Tri-colored Bat (Perimyotis subflavus), Townsend’s Big-eared Bat (Corynorhinus townsendii), and Mexican Free-tailed Bats (Tadarida brasiliensis) – all bats that occur in Big Bend National Park. To date, detections of the fungus in Frio and Victoria Counties are the most southern detections of the fungus in the country and detection within Val Verde County is the closest known proximity of the fungus to Big Bend National Park.
Ammerman, L. K. and E. R. Adams. 2014 Community Structure and Population Trends for Bats in Big Bend National Park, Texas Over the Last 18 Years. Southwestern Association of Naturalists, Poster presentation.
Last updated: November 1, 2022