Body Condition And Food Resources Of White-Tailed Deer On Anticosti Island, Quebec

Abstract

A study was conducted on relationships between seasonal variation in body condition of white-tailed deer (Odocoileus virginianus borealis) and food resources on Anticosti Island, Quebec. Results of the vegetation surveys show that food resources are extremely limited in abundance and variety as snow covers the ground vegetation in winter. Excluding Picea spp., Abies balsamea is by far the most available browse species, accounting for approximately 95% of the available browse biomass in February and March. Analysis of rumen contents suggests that this species accounts for 98.5% of the browse eaten by inland deer between February and mid-April. Lichens account for 9.5% of the dry weight of the rumen content at that time. During the snow-free period, forbs dominate the diet. Both sexes and all age classes show a well defined pattern in body composition with maximum fat levels occurring between September and mid-December and minimum levels between mid-April and mid-June. Fat reserves (ether extraction) in fawns vary from a maximum of 15.3% in fall to a minimum of 0.2% in spring as they lose 41% of their ingesta-free body weight. Composition of the winter body weight loss varies according to sex and age, fat represents 31.7% to 58.9% of the loss and protein 17.8% to 23.0%, water is inversely correlated with fat and ash is a minor part of the loss. The caloric content of the weight loss on an ingesta-free weight basis is lowest in 3-year-old males (3.95 kcal/g) and highest in 2-year-old females (6.86 kcal/g). It is concluded that in association with their low productivity in summer, Anticosti deer must base their winter survival strategy primarily on energy conservation and secondarily on food acquisition during that season.