Vulpes velox (Say, 1823)
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publication ID |
https://doi.org/ 10.5281/zenodo.6331155 |
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DOI |
https://doi.org/10.5281/zenodo.6335051 |
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persistent identifier |
https://treatment.plazi.org/id/03ACCF40-BF2D-FFD2-7B96-FB9FFE1DDB8E |
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treatment provided by |
Conny |
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scientific name |
Vulpes velox |
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Swift Fox
French: Renard véloce / German: Prarie-Flinkfuchs / Spanish: Zorro veloz
Taxonomy. Canis velox Say, 1823 View in CoL ,
River Platte region, USA.
Phenotypically and ecologically similar to V. macrotis ; interbreeding occurs in western Texas and eastern New Mexico, and some suggest these foxes are conspecific. Both are closely related to Arctic Foxes, and some authorities place the latter under Vulpes . Although significant geographic variation exists among Swift Foxes, their classification into northern (hebes) and southern ( velox ) subspecies is probably unjustified. Monotypic.
Distribution. Great Plains in S Canada (Alberta & Saskatchewan) and USA (Montana, and from N Wyoming and SW South Dakota to C New Mexico & NW Texas). View Figure
Descriptive notes. Head-body 50-54- 5 cm for males and 47- 5-54 cm for females,tail 25-34 cm for males and 25-30- 2 cm for females; weight 2- 2-5 kg for males and 1-6- 2-3 kg for females. One of the smallest canids; characteristic black patches on each side of the muzzle. The winter pelage is dark grayish across the back and sides extending to yellow-tan across the lowersides, legs, and the ventral surface of the tail. Black tail tip. The ventral fur is white with some buff on the chest. In summer, the fur is shorter and more rufous. The Swift Fox can be easily confused with the closely related Kit Fox. Dental formula: 13/3, C1/1,PM 4/4, M 2/3 = 42.
Habitat. Predominately short-grass and mixed-grass prairies in gently rolling or level terrain. In Kansas, Swift Foxes have been found to den and forage in fallow wheat fields. Survival rates between foxes in grassland and cropland sites were not significant ly different, suggesting that Swift Foxes may be able to adapt to such habitat in some cases. The distribution and density of dens are considered important components of Swift Fox habitat requirements, particularly in terms of evading Coyote predation or Red Fox competition.
Food and Feeding. Swift Foxes are opportunistic foragers, feeding on a variety of mammals, but also birds, insects, plants, and carrion. Leporids have been reported as a primary prey item in several studies. In South Dakota, mammals accounted for 49% of prey occurrences, with Black-tailed Prairie Dogs (Cynomys ludovicianus) as the primary prey item. In Kansas and Nebraska, murid rodents were the most frequently occurring prey. Insects also present, but likely to constitute only a small portion of biomass. Birds and their eggs are also consumed, as are plant materials, including prickly pear cactus fruit, wild plums, and sunflower seeds, which are consumed relatively frequently but most often in relatively small amounts. Swift Foxes are mostly solitary hunters. Caching of food has been observed.
Activity patterns. Swift Foxes forage throughout the night, and show some crepuscular activity. They will hunt diurnal species such as birds and ground squirrels in the summer.
Movements, Home range and Social organization. The typical social group consists of a mated pair with pups, although occasionally a trio or group of two males and two or three females have been reported, with one breeding female and non-breeding helpers. Home range size averages between 10- 4 km * and 32- 3 km ”. They are territorial: an individual will nearly totally exclude same-sex individuals from its core activity area. Areas used by mated pairs have minimal overlap with areas used by adjacent pairs. Pups remain with the parents until dispersal; in a study only 33% ofjuveniles had left natal home ranges by 9-5 months of age while all recaptured individuals aged 18 months or older had dispersed. Vocal repertoire in captivity consists of courting/ territorial call, agonistic chatter, submissive whine, submissive chatter, precopulatory call, growls, excited yips and barks, and social yips.
Breeding. Primarily monogamous, although additional female helpers are occasionally observed at den sites. Swift Foxes are monoestrous and the timing of breeding (December to March) is dependent upon latitude. The mean gestation period is 51 days and average litter sizes of 2-4-5-7 have been reported. In Colorado, litter sizes were greater for mated pairs with helpers than for those without. Pups open their eyes at 10-15 days, emerge from the natal den after approximately one month, and are weaned at 6-7 weeks of age. Both members of the pair provide for the young, and juveniles remain with the adults for 4-6 months. Swift Foxes are among the most burrowdependent canids and depend on dens throughout the year. They will excavate their own dens and modify the burrows of other species. Dens serve several functions, such as providing a refuge from predators, protection from extreme climate conditions in both summer and winter, and shelter for raising young.
Status and Conservation. CITES not listed. Classified as Least Concern on The [UCN Red List. The Swift Fox has been down-listed from “extirpated” to “endangered” in Canada as a result of reintroduction programs. Following their extirpation by 1938, reintroduction releases since 1983 have established a small Swift Fox population in Alberta, Saskatchewan and Montana, which now constitutes the northern extent of the species’ range. In the USA, the species was cited as “warranted, but precluded” from endangered status under the federal Endangered Species Act. Swift Foxes are primarily prairie specialists, and conversion of grassland to cropland threatens to reduce population sizes and further fragment populations. The conversion of native grassland prairies has been implicated as one of the most important factors in the contraction of the Swift Fox range. Landscape alteration likely influences local and seasonal prey availability, increases risk of predation on Swift Foxes, and leads to competition with other predators such as the Coyote and Red Fox. In Canada, expansion of the oil and gas industry and associated road development are impacting previously isolated prairie areas. Greater urbanization coupled with Coyote control may facilitate Red Fox expansion, which could lead to the competitive exclusion of Swift Foxes in established prairie areas. Landowners who are attempting to protect their livestock from Coyote depredation use poisons illegally and Swift Foxes readily consume such baits.
Bibliography. Andersen et al. (2003), Asa & Valdespino (2003), Avery (1989), Cameron (1984), Carbyn et al. (1994), Covell (1992), Egoscue (1979), Harrison (2003), Herrero et al. (1991), Hillman & Sharps (1978), Hines & Case (1991), Jackson & Choate (2000), Kamler, Ballard, Fish et al. (2003), Kamler, Ballard, Gese et al. (2004), Kamler, Ballard, Gilliland et al. (2003), Kilgore (1969), Kitchen et al. (1999), Mercure et al. (1993), Moehrenschlager (2000), Moehrenschlager & Macdonald (2003), Moehrenschlager & Moehrenschlager (2001), Moehrenschlager & Sovada (2004), Olson et al. (1997), Pechacek et al. (2000), Pruss (1994), Rohwer & Kilgore (1973), Schauster et al. (2002a, 2002b), Sovada & Carbyn (2003), Sovada, Anthony & Batt (2001), Sovada, Roy, Bright & Gillis, (1998), Sovada, Roy & Telesco (2001), Sovada, Slivinski & Woodward (2003), Stromberg & Boyce (1986), Tannerfeldt et al. (2003), Uresk & Sharps (1986), Zimmerman (1998), Zimmerman et al. (2003), Zumbaugh et al. (1985).
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