. The Canadian field-naturalist. 384 The Canadian Field-Naturalist Vol. 103. 1970-71 71-72 72-73 73-74 74-75 75-76 76-77 77- Figure 2. Annual trapped harvest of Arctic Foxes from Sachs Harbour (solid line) and relative abundance of seal carrion (dotted line) from 1970-71 to 1979- 80. From Dome Petroleum (1982), Smith and Stirling (1978), and Stirling et al. (1982). trapping returns. In contrast, adult survival rates in 1975-76 and 1976-77 was much higher as the population was entering the two high catch years of 1976-77 and 1977-78. These patterns were shown by both males and females indicatin
. The Canadian field-naturalist. 384 The Canadian Field-Naturalist Vol. 103. 1970-71 71-72 72-73 73-74 74-75 75-76 76-77 77- Figure 2. Annual trapped harvest of Arctic Foxes from Sachs Harbour (solid line) and relative abundance of seal carrion (dotted line) from 1970-71 to 1979- 80. From Dome Petroleum (1982), Smith and Stirling (1978), and Stirling et al. (1982). trapping returns. In contrast, adult survival rates in 1975-76 and 1976-77 was much higher as the population was entering the two high catch years of 1976-77 and 1977-78. These patterns were shown by both males and females indicating that the changes did not result from sex-specific causes. Although juvenile survival rates were very low (less than 8%) for all years except 1974-75, the survival rate for all years pooled was 23%. This was probably due to the large yearling cohort from 1974-75, which may have biased the calculation. We believe, however, that 23% is likely to be a reasonable estimate of the juvenile survival rate. Because juvenile Arctic Foxes are less experienced in foraging and more naive than adults, they may be more likely to investigate traps and thus be over- represented relative to adults, especially in years when natural food sources are scarce. If so, annual juvenile survival may be underestimated but we have no way of evaluating this. Condition of the animals may also affect their representation in the trapped sample. Adult Arctic Foxes were in significantly better condition than juveniles, and thus might be less likely to turn to trap bait as a food source. Hence, adults may have been underrepresented in the trapped population. Sex ratios of the harvests The 1:1 male to female sex ratio is consistent with that found by Macpherson (1969) and Hammill (19X3). There were no consistent patterns in the ratio of juvenile males to females between years. The sex composition ol the Coastal and inland samples varied widely between years, but not m any consistent pattern. Some of this variabil
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