Research on Akimiski Island, Nunavut, indicates declining numbers of nesting Southern James Bay Population (SJBP) Canada Geese (Branta canadensis interior) while increases have been documented for number of breeding Lesser Snow Geese (Chen caerulescens caerulescens). Low direct recovery rates of goslings is suggestive of late-summer mortality which may be limiting recruitment for Canada geese on Akimiski Island. This study was designed specifically to (1) compare Canada Goose reproductive performance, incubation and brood-rearing behavior in areas of allopatry and sympatry and with Lesser Snow Geese, (2) determine if there are differences in diets of Canada Geese in areas of allopatry and sympatry, and (3) determine if there are differences in diets of Canada and Lesser Snow Geese in the area of sympatry. I documented annual variation for all and spatial variation for some reproductive parameters measured. Results of between-area comparisons of reproductive performance tended to suggest that in some years, Canada Geese nesting in the area of sympatry contribute little towards the maintenance of the island segment of this population. During incubation when females were on nests, male behavior varied as a function of year, area, time-of-day, and incubation stage. Overall, male Canada Geese allocated their time primarily to vigilance, feeding, and resting when females were on the nest. Males in the area of allopatry were more vigilant and fed less compared to males in the area of sympatry. When females were on the nest, their behavior varied relative to time-of-day, incubation stage, and temperature. Females in the area of allopatry were more vigilant than females in the area of sympatry, but overall, females on the nest allocated their time primarily to resting and maintenance. Recess behavior of Canada Geese varied relative to sex, incubation stage, and temperature, but not area, though pairs in the area of allopatry tended to spend more time alert and less time feeding compared to pairs in the area of sympatry. During recesses, males allocated their time primarily to vigilance, whereas females allocated nearly equal proportions of time to feeding and maintenance. Overall, brood-rearing behavior varied relative to year, area, time-of-day, sex/age class, days since peak hatch, brood size, brood density, and temperature. Overall, results are indicative of exploitation competition and I suggest that present foraging conditions are insufficient to meet the energetic demands of breeding Canada Geese, as well as breeding and staging Lesser Snow Geese, molt-migrant Giant Canada Geese, and staging Atlantic Brant. Such an energy deficit is particularly detrimental to the growth and development of Canada Goose goslings resulting in locally poor recruitment which presumably will lead to a much depressed breeding population of Canada Geese on Akimiski Island. (Abstract shortened by UMI.).