ABUNDANCE AND SUMMER OCCUPANCY OF ARCTIC FOX, ALOPEX-LAGOPUS, AND RED FOX, VULPES-VULPES, DENS IN THE NORTHERN YUKON-TERRITORY, 1984-1990

A total of 32 fox dens were known to exist on Herschel Island in 1990. Few dens were located before 1986. Dens located before 1986 were generally larger and, therefore, more likely to be natal than dens found in latter years. Thus a comparison of the proportion of natal fox dens between years was confounded. When proportions of natal dens are compared between years using dens sampled each year from 1986-1990 (n=32), proportions of natal Arctic Fox dens were substantially higher in 1988 (18.8%) and 1990 (18.8%) than in 1986 (6.3%), 1987 (6.3%), and in 1989 (3.1%). No substantial differences were apparent in proportions of natal Arctic Fox dens between all years during 1984-1990, comparing dens known in 1984 (n=14). On the Yukon Coastal Plain, 32 dens were identified during a preliminary survey in 1984, while an aerial stratified random block sampling- census in 1987 yielded a total estimate of 50-63 dens (90% C.I.). One natal Arctic Fox den was found during each of 1985 and 1988, and one Red Fox natal den was observed in 1985, 1987, 1988, and 1989. There was no substantial difference in proportions of natal Arctic Fox, or natal Red Fox dens between years on the Yukon Coastal Plain. Herschel Island had one of the highest densities of Arctic Fox natal dens reported in the literature, whereas the Yukon Coastal Plain had one of the lowest densities.