Grey fox (Urocyon cinereogenteus) COSEWIC assessment and update update status report: chapter 7
Habitat
Habitat requirements
In eastern North America, the grey fox's distribution closely approximates that of the deciduous forest (Fritzell 1987). And in Canada, the grey fox prefers forests and marshes more than open habitats, relative to the red fox (Peterson 1966, Banfield 1974). During the course of a study into red fox behaviour, territoriality and movement, researchers with the Ontario Ministry of Natural Resources Rabies Research Unit had radio-tracked a single adult male grey fox (P. Bachmann, pers. comm.) from October 1980 to November 1981 in Lambton County, Ontario (Bachmann and Lintack 1982). The study area was typical of southwestern Ontario agricultural land: cultivated fields interspersed with deciduous woodlots dominated by sugar maple (Acer saccharum) and crisscrossed by a network of roads (Bachmann and Lintack 1982). Within this study area, the grey fox male was located most often within woodlots and moved most often within 100 m of the woodlot edge. However, the male did move into open, less wooded areas and occasionally crossed roads (Bachmann and Lintack 1982). We believe that this is the only quantitative study of a grey fox in Canada.
In the United States, grey foxes prefer woodland habitat when it is interspersed with open areas or farmland (Samuel and Nelson 1982; Fritzell 1987 and references therein). The implication of this finding is that grey foxes use the many edges found in this type of landscape, where they can benefit from the shelter provided by the forest and the food resources present in the open areas (Richards and Hine 1953; Wood et al. 1958; Trapp and Hallberg 1975; Petersen et al. 1977; Bachmann and Lintack 1982). However, whether this apparent preference is a real phenomenon, or an artifact caused by the fact that most radiotelemetry studies have been carried out in a mosaic of forested and nonforested cover types (Fritzell 1987), is unclear. This point is highlighted by a study of grey fox habitat preference by Haroldson and Fritzell (1984), who studied grey foxes in an oak-hickory dominated landscape containing only about 5% open area, and found that grey foxes seldom used nonforested habitat.
Both daily and seasonal patterns of habitat use by grey foxes have been described. Grey foxes used woodlands more during daylight hours than at night (Follmann 1973, cited in Fritzell 1987; Haroldson and Fritzell 1984). In southern Illinois, wooded areas were used more than old fields in the winter and spring months, whereas the reverse was true for the summer and fall (Follmann 1973, cited in Fritzell 1987).
Grey foxes use a variety of locations for denning, including rock outcrops, hollow trees or logs, cavities under rocks, underground burrows dug by other animals, piles of brush, slab, wood or sawdust, and abandoned buildings (Trapp and Hallberg 1975; Fritzell 1987). However, grey fox dens are usually located in an area of dense brush and within 0.4 km of a water source (Layne and McKeon 1956; Sullivan 1956). Bachmann and Lintack (1982) found three den sites, all of which were within brush piles.
Apart from the general conclusion that grey foxes prefer wooded habitat, it should be noted that grey foxes are habitat generalists, as evidenced by: their ability to use reclaimed surface mines (Yearsley and Samuel 1980) and rural residential areas (Leopold 1959; Harrison 1997), and by their extensive geographic distribution (Fig. 2).
Trends
Due to pressure from development, it seems likely that the amount of wooded habitat along the Canada-U.S. border in Manitoba, Ontario and Quebec will continue to decline, although perhaps not as quickly as in previous years.
Protection/ownership
The grey fox is thought to occur in St. Lawrence Islands National Park (Parks Canada 2000) and has been found in Fish Point Provincial Nature Reserve, Pelee Island. It is also thought to occur in the Whiteshell Provincial Park region in southeastern Manitoba (I. McKay, pers. comm.). Its occurrence in other parks and reserves is unknown. It is likely that much of the habitat in Canada occupied by grey foxes is under private ownership.
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