Expanded abstract Reproductive status of female muskoxen harvested on Banks Island,

Age of first breeding and frequency of breeding are good indicators of the nutritional status of a population. Calving by younger age classes is typical of rapidly increasing muskox (Ovibos moschatus) populations (Jingfors and Klein, 1982; Thing et al, 1984). The muskox popula-tion on Banks Island has been expanding since the 1970s. A n increase in age of first reproduc-tion, decline in body condition and productivi-ty, increase in incidence of disease, and lowered survivorship (density dependent effects) may manifest themselves with increasing population density. We hypothesize that as the muskox po-pulation increases on Banks Island there wil l be an increase in the age of first reproduction and in the proportion of adult females calving in al-ternate years. Population estimate surveys were conducte