Scales of habitat selection for black bears (Ursus americanus) in the Trans-Pecos region of Texas.
Rice, Mindy*,1, Ballard, Warren1, Fish, Ernest1, Holdermann, David2, 1 Texas Tech University, Lubbock, TX, USA2 Texas Parks and Wildlife, Alpine, TX, USA
ABSTRACT- Black bears were once widespread across Texas, but their numbers were reduced in the early 1900′s. A small number of individual bears from northern Mexico have recolonized the Trans-Pecos region of Texas in recent years. Black bears are a generalist species and travel long distances to obtain food. It is important to determine the vegetation types bears are preferentially selecting not only at fine scales, but also at broader scales which may define potentially suitable habitat for black bear. We utilized a geographic information system to map all bear sightings as well as vegetation types for 9 counties of the Trans-Pecos region. We utilized 3 scales: 1) the point location of the bear sighting, 2) a ′fine area scale′ representing the average daily movement of black bears in our region, 3) a ′broad area scale′ representing the average home range of black bears. The habitat selection information was then summarized in ArcGIS 9.0 for each scale and compared among scales and to the total available vegetation in the region. Preliminary results indicate there was no difference between the fine and broad area scales of vegetation selection (P = 0.15). However, there was a difference in vegetation selection between point locations and the fine and broad area scales (P< 0.001). There was also a significant difference between the point, fine, and broad area scales compared to the regionally available vegetation (P < 0.0001). Our results suggest that black bears in the Trans-Pecos region are selecting vegetation differently at the point scale versus the fine and broad area scales indicating that point locations may inaccurately measure selection by black bears. Even so, the bears are selecting vegetation not based on availability when comparing all scales to the available regional vegetation. The black bear is an endangered species in Texas so managing at broader scales and focusing on vegetation preferences may support the expansion of this population.&cover;ŝ&sscript;∼′
Key words: Black bear, habitat selection, scale, GIS
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