GENETIC CHARACTERISTICS of RED FOXES in NORTHEASTERN OREGON BALD GREGORY AGREEN Owl Ridge NRC, 22116 45Th Avenue SE, Bothell, WA 98021 USA; [email protected]
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A OF V MET FIRST RE Raring PREV Richar GENERAL FIRST Jef BEHA GENETIC CHARACTERISTICS OF RED FOXES IN NORTHEASTERN OREGON BALD GREGORY AGREEN Owl Ridge NRC, 22116 45th Avenue SE, Bothell, WA 98021 USA; [email protected] CA BENJAMIN NSACKS Mammalian Ecology and Conservation Unit, 248 CCAH, Veterinary Genetics Laboratory, University of FIRST California Davis, One Shields Avenue, Davis, CA 95618 USA RA LEONARD JERICKSON Oregon Department of Fish and Wildlife, 107 20th Street, La Grande, OR 97850 USA RAPT KEITH BAUBRY US Forest Service, Pacific Northwest Research Station, 3625 93rd Avenue SW, Olympia, WA 98512 USA NORTHWESTERN NATURALIST 98:73–81 AUTUMN 2017 GENETIC CHARACTERISTICS OF RED FOXES IN NORTHEASTERN OREGON GREGORY AGREEN Owl Ridge NRC, 22116 45th Avenue SE, Bothell, WA 98021 USA; [email protected] BENJAMIN NSACKS Mammalian Ecology and Conservation Unit, 248 CCAH, Veterinary Genetics Laboratory, University of California Davis, One Shields Avenue, Davis, CA 95618 USA LEONARD JERICKSON Oregon Department of Fish and Wildlife, 107 20th Street, La Grande, OR 97850 USA KEITH BAUBRY US Forest Service, Pacific Northwest Research Station, 3625 93rd Avenue SW, Olympia, WA 98512 USA ABSTRACT—The Rocky Mountain Red Fox (Vulpes vulpes macroura), once common in the Blue Mountains ecoregion of northeastern Oregon, was considered rare in eastern Oregon by the 1930s and thought to be extirpated by the 1960s, when putatively new Red Fox populations began to appear. Although the new foxes were long presumed to be nonnative (originating from fur-farms or deliberate release), they were often phenotypically similar to native Red Foxes, suggesting the alternative possibility that they arose from range expansions, either by small numbers of remnant native foxes at higher elevations or by Rocky Mountain Red Foxes to the east. In this study, we used mitochondrial DNA to investigate the origins of extant Red Fox populations in northeastern Oregon. Our findings show that both native and nonnative sources contributed to the Red Fox populations currently occupying this region. In particular, Red Foxes in montane habitats of their former range in northeastern Oregon reflect predominantly native ancestry, whereas those in more lowland habitats outside the boundaries of their former range represent a mix of native and nonnative ancestry. Recognizing the existence of foxes with native ancestry in northeastern Oregon may shape management decisions regarding this species, especially in respect to control versus conservation. Key words: cytochrome b, D-loop, haplotype, mitochondrial DNA, northeastern Oregon, recolonization, Rocky Mountain Red Fox, Vulpes vulpes macroura Since European colonization, Red Fox (Vulpes generations of captive breeding and selection, vulpes) populations in North America have were derived primarily from a small number of expanded both from habitat alteration (Lloyd wild-caught individuals from southeastern Can- 1980; Nowak 1991) and anthropogenic translo- ada and Alaska (Statham and others 2012). From cations (Long 2003). Farmland development has a conservation standpoint, Red Foxes that created open-field habitats favored by this originated from translocations represent inva- species, while foxes have been translocated sive nonnative species that could threaten the across the continent either for sport (hound genetic integrity of native conspecifics through hunting) or to bolster fur trapping (Wilcomb hybridization (Krueger and May 1991) or com- 1948; Mace 1970; Aubry 1984). New Red Fox petition (MacDonald and others 1989; Simberloff populations have also been established by fur- 1997; Lockwood and others 2007). However, all farm escapees (Ashbrook 1923; Witmer and wild Red Fox populations exhibit variable Lewis 2001). Fur-farm foxes, which reflect many morphological characteristics, both between 73 74 NORTHWESTERN NATURALIST 98(2) and within standard color-phases (red, cross, publication, native foxes had disappeared from and silver); consequently, distinguishing native Oregon, and that the ‘‘foxes today are descen- from nonnative Red Foxes based on coat color is dants of eastern stock transplanted in the Will- very difficult, although subtle differences in red- amette Valley’’. Although Wilcomb (1948) did phase pelage color between the groups do occur describe several instances of nonnative fox (Bailey 1936). Conservation efforts to control translocations into the Willamette Valley be- nonnative Red Foxes might have led to the tween 1900 and 1924, which is likely the basis for unintentional removal of native foxes, which is Mace’s conclusions, Verts and Carraway (1998) of special concern where the native fox may be could find no evidence to support Mace’s naturally rare or endangered. Thus, understand- contention that the original foxes were extirpat- ing the genetic affinities and origins of Red Fox ed state-wide. populations in northeastern Oregon will be Mace (1970) also identified (on a range map) essential for the conservation and recovery of small pockets of presumably nonnative Red Fox native foxes in this region. occurrence in northeastern Oregon, especially in In western North America, native foxes the irrigated farmland of northern Malheur generally inhabit mountainous regions, where County on the Oregon-Idaho border. These foxes habitat conditions at high elevations are believed first appeared in fur-harvest records from to closely parallel the colder environmental Oregon in 1964, and by the late 1980s .100 conditions that existed in the southern refugium foxes were being harvested annually (Verts and during the last glacial maximum where the Carraway 1998). Because Red Foxes in the mountain foxes evolved (Aubry and others Willamette Valley would have to travel approx- 2009). Three montane subspecies are currently imately 150 km to get across the Cascade Range, recognized: the Rocky Mountain (V. v. macroura), and then cross approximately 350 km of very Sierra Nevada (V. v. necator), and Cascade (V. v. dry and largely unforested habitat to reach the cascadensis) Red Foxes (Aubry 1983; Perrine and Blue Mountains, they were an unlikely source others 2007). Mountain Red Foxes tend to be for these new populations. rare. The northern Malheur County irrigated farm- The Rocky Mountain Red Fox is native to the ing district is the Oregon extension of an Blue Mountains ecoregion of northeastern Ore- expansive Snake River Plains farming area that gon and southwestern Washington (Bailey 1936). bisects southern Idaho. Red Foxes began ap- Between 1825 and 1857, 1597 Red Fox pelts were pearing in the Idaho portion of the Snake River traded at Fort Nez Perce, located on the Walla Plain about 1960 (Fichter and Williams 1967). Walla River (Cowan 1938). Based on trade The lack of previous records from these low- patterns, Cowan (1938) and Stern (1993) con- elevation (700 to 1600 m) farming areas, coupled cluded that the majority of these foxes would with known occurrences of fox-fur farms in the have come from the general vicinity of the fort, region (Fichter and Williams 1967), suggested which in this case would likely have been the that nonnative Red Foxes became established in Blue Mountains of northeastern Oregon and southern Idaho in the early 1960s, eventually southeastern Washington. In 1914, Dice (1919) progressing downriver to Oregon by the late investigated the fauna of southeastern Washing- 1960s (the 1st record was in 1967) and early ton and reported that Red Fox were ‘‘commonly 1970s. However, Fichter and Williams (1967) found on the ridges of the Blue Mountains’’.By described a fox with red-phase pelage charac- the 1930s, however, 2 decades of intensive fox teristics more similar to native mountain foxes trapping during an inflated fur market (Bailey (yellow, buff, or tawny), and as a result 1936), along with the intensive predator-reduc- tentatively classified these foxes as V. v. macro- tion programs initiated by the Bureau of ura, with possible admixture with fur-farm Biological Survey (DeCalesta 1976), had greatly escapees. reduced their number, although Bailey (1936) Red Foxes began appearing elsewhere in stated ‘‘their extermination. .has not been ac- northeastern Oregon in the mid-1990s (Verts complished’’. No Red Foxes were reported in and Carraway 1998), and by 2010 populations harvest records from southeastern Washington were well established in 8 counties (and in between 1938 and 1980 (Aubry 1984), and Mace adjacent Walla Walla County, Washington), (1970) concluded that by the date of his including the original mountainous range de- AUTUMN 2017 GREEN AND OTHERS:GENETIC CHARACTERISTICS OF RED FOXES 75 scribed by Bailey (1936) as well as farmlands in the hypothesis that Red Foxes were largely both the Snake River Plain and Columbia River native: (1) haplotypes are all or mostly native; Plateau. and (2) multiple native haplotypes occur in the The possible origins of extant Red Fox population. populations in northeastern Oregon include expansion by foxes in the Snake River Plain into METHODS similar farmland habitat in northeastern Oregon, Study Area fox-farm escapees (including a known release of foxes from a fur farm near Hermiston in 1987; M The northeastern portion of Oregon where Kirsch, Oregon Department of Fish and Wildlife, genetic samples were collected included 3 pers. comm.), down-slope expansion by mem- ecoregions: the Blue Mountains, Columbia Pla- bers of a small, persistent native population in teau, and Snake River Plain (USEPA 2003; Fig. the Wallowa Mountains, immigration from 1). The Blue Mountains