Northern Prairie Wildlife Research Center
Habitat and History. Striped skunks were distributed throughout the prairie pothole region before settlement but were most numerous in bushy or wooded areas (Seton 1909, 1953; Bailey 1926; Bird 1961; Kiel et al. 1972). They have remained widespread and generally common throughout the region although populations have fluctuated greatly in local areas (N. Criddle 1929; Banfield 1941; Soper 1946; Rand 1948b; Bird 1961; Wade-Smith and Verts 1982; Jones et al. 1983). Striped skunks are suited to living near humans but may not have benefitted greatly from habitat changes by agricultural development. They forage primarily on insects and use underground dens for rearing young and for dormancy in winter (Wade-Smith and Verts 1982; Rosatte 1987). Plowing destroys feeding areas and denning sites. Major causes of mortality are killing by humans, deaths in winter (e.g., starvation), and disease (Bjorge et al. 1981; Wade-Smith and Verts 1982). Striped skunks are easily trapped and large numbers are caught annually by fur trappers. Rabies is a major disease of striped skunks in the eastern two-thirds of the region. Rabies began spreading westward across the prairie pothole region of Canada in the late 1950's and prompted implementation of programs to eradicate striped skunks in some western areas (Tabel et al. 1974; Schowalter and Gunson 1982; Rosatte and Gunson 1984).
Population Structure. Striped skunk populations in spring are composed of loose aggregations that often consist of an adult male and one or more adult females. Some adult males disperse to new areas in mid- to late spring (Sargeant et al. 1982). Home ranges of sexes overlap within and among social aggregations (Ewer 1973; A. B. Sargeant and R. J. Greenwood, unpublished data). Average home range sizes of adult skunks in the prairie pothole region range from 1.2 to 2.5 km2 for females and from 2.9 to 3.1 km2 for males (Bjorge et al. 1981; Rosatte and Gunson 1984; Greenwood et al. 1985).
Distribution and Abundance. Striped skunks were in all study areas each study year (Appendix Table 5). The percentages of study areas with common or more abundant striped skunks did not differ between Canada and the United States (Appendix Table 6) and between the prairie and the aspen parkland (Appendix Table 7). Striped skunks were numerous in 6 (18%), common in 26 (79%), and uncommon in 1 (3%) study area (Fig. 9). Although they were captured (Appendix Table 9) and tracks were found (Appendix Table 5) in all study areas in Canada during all study area-years, we found no relation between capture rates of striped skunks and the percentage of quarter sections in which tracks of striped skunks were found (r = 0.41, 14 df, P = 0.119). (No livetrapping of striped skunks was conducted in study areas in the United States.) Variation in capture rates indicated differences in abundance were greater than revealed by the track index; populations were not high in any study area. The highest capture rate (0.125 per trap-night in one study area [Hanley] in 1985) was less than half that reported by Greenwood et al. (1985) for a study area in North Dakota where the density of adult striped skunks in spring was estimated to be between 0.5 and 1.0/km2 (A. B. Sargeant and R. J. Greenwood, unpublished data). Densities of >5 striped skunk/km2 were reported by many investigators (Rosatte 1987). The removal of 6-26 striped skunks annually from each of three study areas (Eldridge, Fredonia, Lake Park; Appendix Table 3) may have lowered the track indices. Captures and tracks of striped skunks were widely distributed in all except two study areas (Gayford, Earl Grey).
Fig. 9. Percentage of searched quarter sections (in black) by study area in which skunk tracks were found or in which the abundance of tracks was estimated during two systematic annual searches in April-June in >= 1 study year and ratings of the abundance of skunks in each area, 1983-88. Results for study areas searched >1 year were averaged; study areas are in the prairie pothole region.