Demographic Patterns and Limitation of Grey Wolves, Canis lupus, in and Near Pukaskwa National Park, Ontario

Abstract

In response to concern regarding the growth and long-term viability of the wolf population in and near Pukaskwa National Park, a study of demographic patterns and limitation of radio-collared wolves (Canis lupus) was completed between 1994 and 1998. The mean annual finite rate of increase (0.96) suggested that population growth of wolves was limited and declining slightly. Small pack sizes, high cumulative mortality, and low reproductive success also suggested a declining population. Two limiting factors, ungulate biomass and human-caused mortality, were examined to determine the importance of each in limiting the population growth of wolves. Ungulate biomass was involved because occurrence of natural-caused mortality was high (9 of 17 wolves) compared with other studies. In addition, consumption rates were low and similar to other studies where starvation and other signs of malnutrition were noted. Further, Moose densities in the study area were low to moderate and below thresholds indicating nutritional stress for wolves. Occurrence of human-caused mortality was high (8 of 17 wolves) suggesting that it was also an important limiting factor, particularly given the low availability of ungulate biomass and reproduction noted in this study. Based on present demographic patterns, ungulate biomass, and human-caused mortality, the wolf population likely will remain at present low densities or continue to decline.