Grey fox (Urocyon cinereogenteus) COSEWIC assessment and update update status report: chapter 6

Distribution

Global range

The grey fox is generally found in the southern half of North America, from southern Canada to northern Colombia and Venezuela (Fig. 2). Within that global range, the grey fox is absent from parts of mountainous northwestern United States, the Great Plains and eastern Central America (Fritzell and Haroldson 1982). However, the grey fox has expanded its range in the last 50 years, and is now found in 45 or more American states (Samuel and Nelson 1982, please see Fritzell and Haroldson 1982 for a list of references detailing the grey fox’s range extension in the U.S.). In particular, grey foxes have expanded their range northward within several northeastern and Great Lakes states, including: Minnesota (B. Berg, pers. comm.), Wisconsin (J. Olson, pers. comm.), Michigan (T. Reis, pers. comm.) and New Hampshire (E. Orff, pers. comm.).


Figure 2. The global distribution of the grey fox, Urocyon cinereoargenteus

Figure 2. The global distribution of the grey fox, Urocyon cinereoargenteus.

Modified from Fritzell and Haroldson 1982.

Canadian range

Archeological evidence (Wintemberg 1921, 1928, 1936, 1939, 1948; Downing 1946) suggests that the grey fox was almost as common as the red fox in southern Ontario as far north as Midland prior to European occupation (Downing 1946). Grey foxes were extirpated from Canada around the time of the first European colonists (Downing 1946) over 350 years ago. However, Downing (1946) believed that the grey fox was extirpated by some factor other than the newly arrived Europeans because no author of the colonial period described seeing a grey fox in Ontario and, “If [grey foxes] were present in the numbers suggested by the remains in the Indian village sites, one would hardly expect its tree-climbing habits to have escaped comment by some early writer” (Downing 1946, page 45). Grey foxes were absent from Ontario until the late 1930s or early 1940s (Downing 1946) when populations in the northeastern and Great Lakes U.S. states expanded northward (Hamilton 1943). The present apparent northward extension of the grey fox's range may be the result of climatic changes. Waters (1964) suggested that the grey fox's range expanded northward and eastward in the warm Hypsithermal Period (5000-2000 B.C., Dorf 1959) and then contracted southward when conditions cooled, and that this pattern repeated itself around 1000-1300 A.D. He speculated that the grey fox's recent expansion into New England was also related to a warming trend (Waters 1964, although see Waters 1967 for complicating evidence from Martha’s Vineyard). The northward expansion of the grey fox in Wisconsin (WI) and Minnesota (MN) is thought to be at least partly attributable to warmer than average weather in the 1990s (J. Olson, pers. comm. for WI; B. Berg, pers. comm. for MN). Hersteinsson and Macdonald (1992) implicated climate change in the northward migration of the boundary between the geographic distribution of red foxes and arctic foxes (Alopex lagopus).

Banfield (1974) and earlier authors noted that the grey fox has been found in three regions in Canada: 1) the Rainy River District of Ontario (west of Lake Superior) and into southern Manitoba, 2) the north shore of Lake Erie from Windsor to Niagara Falls, and 3) the northeastern shore of Lake Ontario and into Quebec's eastern townships north of Maine (Banfield 1974). Each one of these three regions was thought to contain a separate subspecies of grey fox (Banfield 1974). These three subspecies are U. c. ocythous Bangs, U. c. cinereoargenteus (Schreber), and U. c. borealis Merriam respectively, and are found in the U.S. states directly south of the three Canadian regions (Hall 1981). With the exception of one recent record from Manitoba, however, all records of grey fox in the last 20 years have been from Ontario. The two regions of Canada with substantial numbers of grey fox records will henceforth be referred to by the abbreviations: WLS (West of Lake Superior) and SO (Southeastern Ontario) (Fig. 3a). The distribution of recent sightings, however, suggests that there may only be a breeding population on Pelee Island and records from elsewhere in Ontario may represent dispersing individuals from the United States.

To date, we have collected 74 records of grey fox sightings or captures in Canada (Appendix 1). Eight of these are from WLS and 65 are from SO, the latter including 1 record from Quebec from over 100 years ago (Appendix 1). Only one of these records is of an individual known to have been born in Canada (1 June 1998, Pelee I., Ontario; Appendix 1). The earliest post-Columbian record is from 1894 near Johnville, Quebec (Appendix 1) and the latest is from January 2001 on Pelee Island, Ontario (Appendix 1), although specimens were recovered from both regions in 2000 (see Appendix 1). A single grey fox individual was trapped near Lake Athabasca in Alberta (Fig. 3a, Moore 1952). However, Smith (1993) considers this specimen to be accidental and not representative of an established population.


Figure 3a. The Canadian distribution of the grey fox, Urocyon cinereoargenteus

The Canadian distribution of the grey fox (see long description below).

Modified from Banfield 1974.

Description of Figure 3a

The grey shaded areas represent the two major regions of occurrence of grey fox in Canada: 1) the Rainy River District of Ontario (west of Lake Superior) and into southern Manitoba (WLS), and 2) southeastern Ontario (SO). Small black dots indicate grey fox records within these regions, and the large black dot in northern Alberta represents an extralimital grey fox record. A question mark in southeastern Manitoba represents a general report of grey foxes being trapped in the Whiteshell Provincial Park area, but no specific records (I. McKay, pers. comm.).

 


Figure 3b. Distribution of grey fox, Urocyon cinereoargenteus, records in southern Ontario

Distribution of grey fox records in southern Ontario (see long description below).

Modified from Dobbyn 1994.

Description of Figure 3b

Hollow circles indicate records prior to 1980. Solid circles indicate records from 1980 or later. Numbers are used when there is more than one record for a specific location (e.g. there are 17 grey fox records for Pelee Island). A question mark in southeastern Ontario represents an unverified report of grey foxes in St. Lawrence Islands National Park (J. Leggo, pers. comm.; Parks Canada 2000).

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