American black bears (Ursus americanus) have recolonized Big Bend National Park (BIBE), Texas, in the past 15 years from adjacent habitat in northern Mexico. Range expansion by the Big Bend bear population across the Chihuahuan Desert landscape has considerable consequences for the recolonization of areas north of BIBE in western Texas (Glass, Del Norte, and Davis Mountains). We studied black bear ecology from 1998 to 2001 in BIBE. Thirty bears were marked (15 with radiocollars) during the study, including newborn cubs. Home ranges of bears (males x̄ = 97.7, SE = 35.8 km2, females x̄ = 32.1, SE = 4.3 km2) were larger than in southwestern populations in Arizona and northern Mexico, but smaller than those in the nearby Black Gap Wildlife Management Area (BGMWA). Bears were mainly restricted to the Chisos Mountains and their foothills, with 65% of radiolocations in the pinyon (Pinus cembroides)-oak (Quercus spp.)-juniper (Juniperus spp.)-talus-meadow-grass vegetation association. Habitat selection analyses indicated that bears used oak-dominated vegetation types more than expected based upon availability. Bears were more likely than random to be <100 m from anthropogenic features (e.g., roads, trails), but that effect was much stronger in summer when visitor use was low. These data provide predictive capability to managers regarding recolonization of other montane islands north of BIBE and provide information that will help managers ensure the persistence of the small island population of black bears in BIBE.
- Volume 14
- Issue 2
- Pages 120-129
- Publication Date 1 January 2003
- DOI
- File Size 700.33 KB
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