Current distribution of the swift fox (Vulpes velox) in Texas

Date
2007-12
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Abstract

Distribution and abundance data suggest that the swift fox (Vulpes velox) has experienced range wide declines in distribution and density. Swift fox are associated with short grass and mixed grass systems in the Great Plains region. In Texas, these habitats have undergone extensive alteration, primarily as a result of agricultural development. Historic records indicated swift fox occurred in 79 counties in Texas. The current distribution of swift fox in the state is unknown, but surveys conducted in 1996 and 1997 indicated the species’ range was considerably reduced. We used scat surveys and live trapping to assess the current distribution of the species. We established 93 scat survey transects, representing 550 survey kilometers, in 35 counties encompassing the majority of remnant mixed grass and short grass habitat in Texas. Transects were surveyed once per year between 07 July and 31 November in 2005 and 2006. Laboratory DNA analysis was conducted on scats to determine the identity of the depositing species. We collected 166 scats for both years combined. Of these, 9 were identified as swift fox scats. All swift fox scats originated from 1 of the 35 counties surveyed. Surveying the entire 35 county area using live traps was logistically unfeasible. We selected counties which we believed had the highest likelihood of having resident swift fox based on proximity to known swift fox populations and total remnant grassland. We surveyed 7 counties during the 2005 and 2006 field seasons. Grassland fragments in each county were randomly selected and surveyed for 2 consecutive nights once per year. We captured 39 individual swift fox during both years combined. We detected swift fox in 2 of the 35 counties surveyed. Our results indicated that the current swift fox distribution in Texas is significantly reduced from the historic species distribution.

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Keywords
Texas, Vulpes velox, Swift fox, Molecular scatoloty
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