Lack of Reproduction in Muskoxen and
Arctic Hares Caused by Early Winter?
Introduction
Because of the remoteness and inaccessibility of Canada's High Arctic islands, few details are known about their wildlife populations and the factors that affect these populations. For example, there appear to be only three publications touching on arctic hare ecology (Parker, 1977; Klein and Bay, 1995; and Schaefer et al., 1996) and, although muskoxen have been well studied, "we have no idea why periodic declines occur" (Theberge, 1972:28). Thomas et al. (1981) saw extreme winter weather as a logical cause of muskox declines, and Gunn et al. (1989) proposed a hypothesis involving above-average snow depths in spring. Excessive snowfall and ice crust have also been blamed for muskox declines, yet the effects of these conditions vary throughout muskox range (summarized by Forchhammer and Boertmann, 1993).
Densities of arctic mammals tend to be lower than those of mammals inhabiting lower latitudes, so population and productivity declines are more serious and thus more noteworthy. This article reports evidence of such a decline in muskox and arctic hare populations on part of Ellesmere Island during winter 1997-1998, when neither ice crusts nor excessively deep snow prevailed. An alternative weather-based hypothesis is offered.
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