Transbounday Movement by Black Bears between west Texas and northern Mexico

Black bears are listed as a state “threatened” species in Texas, and “endangered” in Mexico.  In the 1990s black bears began slowly recolonizing areas of the Trans-Pecos through dispersal from adjacent Coahuila, Mexico.  The recolonizing bears are crossing international borders from Mexico and settling in areas such as Big Bend National Park and Black Gap Wildlife Management Area. BRI partnered with wildlife biologists from Mexico in order to gather data on black bear movement patterns across the U.S./Mexico border. We captured black bears in Black Gap Wildlife Management area (southern Brewster county near the US/Mexico border) and fit them with GPS satellite collars.  Location data for each collared bear acquired via satellite allowed us to determine how bears use transboundary habitat corridors across the international border.  We suspect that drought conditions during the course of this study limited the number of bears available for capture, however, we were able to capture two male black bears during summer 2011.  Both dispersed into Mexico at around the same time (September 2011) and location when the water tanks in Black Gap WMA went dry. 

The goal of this study was to help biologists and researchers better understand movements and habitat use of black bears in a desert ecosystem, and to establish working relationships with international wildlife agencies so that wildlife crossings along the US/Mexico border are managed efficiently.

Black bears were captured using barrel and culvert traps and fitted with GPS satellite collars which collected 4 locations daily. 

 

tank

A water tank at Black Gap Wildlife Management Area frequently used by black bears that died up completely during the 2011 drought.