Distribution and Status of the Red Fox in Idaho

The origin of recently established red fox populations in the United States: translocations or natural range expansions?

“…These records suggest that the southern range boundary of native red Although red foxes were historically absent or extremely rare in the central and western United States (with the exception of high-elevation areas in the western mountains and the Sacramento Valley of California), they became established in many lowland areas during the 1900s (Aubry 1983(Aubry , 1984Bailey 1936b;Sacks et al 2010;Whitlow and Hall 1933). These recently established populations could have resulted from human translocations of fur-farm animals that subsequently escaped or were released (Aubry 1983(Aubry , 1984Lewis et al 1999), continental-scale range expansions from the East (Kamler and Ballard 2002), natural range expansions by native montane populations (Bailey 1936a;Fichter and Williams 1967;Verts and Carraway 1998), or human translocations from native montane populations for fur farming.…”

“…Populations of unknown origin began appearing outside these ecologically restricted areas during the 1900s (Aubry 1983(Aubry , 1984Fichter and Williams 1967;Kamler and Ballard 2002;Lewis et al 1999;Verts and Carraway 1998). Most recently established populations of the red fox in the West were hypothesized to have originated from translocations from the East or from the escape or release of fur-farm animals that were presumably imported primarily from Prince Edward Island, Canada, or southern Alaska (Aubry 1983(Aubry , 1984Balcom 1916;Laut 1921;Lewis et al 1999;Petersen 1914;Westwood 1989).…”

“…Most recently established populations of the red fox in the West were hypothesized to have originated from translocations from the East or from the escape or release of fur-farm animals that were presumably imported primarily from Prince Edward Island, Canada, or southern Alaska (Aubry 1983(Aubry , 1984Balcom 1916;Laut 1921;Lewis et al 1999;Petersen 1914;Westwood 1989). However, others hypothesized that the recent (after 1940) colonization of previously unoccupied habitats in southern Idaho (Fichter and Williams 1967) and in the Willamette Valley in Oregon (Verts and Carraway 1998) could partly or fully reflect natural range expansions by native populations or increases in density by previously undetected native populations. In the Central Valley of California, where the native Sacramento Valley red fox (V. v. patwin) is contiguous with a population of nonnative red foxes, the 2 populations interbreed within a narrow hybrid zone, suggesting the possibility of admixture in other locations as well (Sacks et al 2011).…”

Genetic structure of Greater Sage-Grouse (Centrocercus urophasianus) in a declining, peripheral population

“…. The abundance of red fox (Vulpes vulpes) and raccoon (Procyon lotor) may have substantially increased in sage-grouse habitats because of landscape changes (Fichter and Williams 1967). …”

North American montane red foxes: expansion, fragmentation, and the origin of the Sacramento Valley red fox

“…Moreover, although mitochondrial genetic diversity apparently declined in the Rocky Mountain population (including some lowland and montane regions of the intermountain West), red foxes apparently have expanded their range or increased in abundance in some areas (Fichter and Williams 1967). Until recently, it was presumed that these locations were invaded by nonnative red foxes from the East Ballard 2002, 2003).…”