dc.description.abstract | The red foxes (Vulpes vulpes) indigenous to the mountains of the western United
States are high-elevation specialists that could face range reduction due to climatic
warming, as well as potential encroachment, loss of adaptive alleles, and displacement
by introduced nonnative red foxes. I investigated the genetic integrity of the native
Rocky Mountain red fox (V. v. macroura) in Colorado, through analysis of the
composition, distribution, and patterns of gene flow between native and nonnative red
fox populations along an elevational gradient. The study area spanned the high plains
around Denver in the east to the alpine zone of the Rocky Mountains adjacent to
Gunnison and Crested Butte in the west. I used microsatellite and mitochondrial DNA
(mtDNA) from Colorado foxes, along with previously published reference data from
other native western and nonnative populations, to evaluate the distribution of native
versus nonnative ancestry and its relationship to elevation, distance, and landscape-type.
Nonnative red fox ancestry predominated in Denver and low-lying areas, whereas native
ancestry was most prevalent at high elevations. The genetic integrity of foxes at higher
elevations (i.e., within the historical native range) was greater in terms of mtDNA than
nuclear DNA, consistent with higher male-mediated gene flow. At high elevations,
nonnative admixture was most pronounced in human-altered landscapes. My findings
provide baseline data necessary to monitor future trends of these Rocky Mountain
populations and serve as foundations for proactive management of the two endangered
mountain red fox subspecies to the west. | en |