Reproductive Ecology, Bioenergetics, and Experimental Removal of Local Giant Canada Geese (Branta Canadensis Maxima) in Central Missouri

Populations of Giant Canada Geese (Branta canadensis maxima) have increased dramatically throughout most of the Mississippi Flyway. This population expansion has been accompanied by an increase in goose-related problems, including depredation of agricultural crops, airport hazards, fecal contamination of water used for drinking or swimming, and damage to lawns, parks, beaches, and golf courses, caused by overgrazing, trampling, feathers, and defecation. Failure to control giant Canada goose populations through traditional harvest methods such as hunting, has prompted interest in alternative harvest methods (nest manipulations, welfare harvest, and nesting female harvest) as a means of reducing goose numbers. The intent of this research was to generate long-term reproductive, survival and bioenergetics data and to utilize these data to develop a population model specific to Missouri Giant Canada Geese. The model was then used to identify population parameters that most influence population growth and to evaluate proposed management actions. Sensitivity analyses indicated that the effect of adult survival on population growth was much greater than any other population parameter. Alternative harvest simulations indicated that nesting female harvest was the most effective means of reducing populations to statewide management objectives. From a management perspective, our results indicate that efforts to control numbers of giant Canada geese should focus on reducing adult survival, in particular adult female survival. It is unlikely that the required reduction in adult survival necessary to reach management objectives will be achieved through traditional harvest methods. Therefore, a combination of non-hunting lethal alternatives will be required.