Behavior of Cackling Canada Geese during brood rearing

We studied behavior of Cackling Canada Goose (Branta canadensis minima, cacklers) broods between 1992 and 1996 on the Yukon Delta National Wildlife Refuge in western Alaska. An increase in time spent foraging by goslings during our study was weakly correlated with an increase in the size of the local breeding population. Amount of time spent feeding by adults and goslings increased throughout the brood rearing period. Overall, goslings spent more time feeding than either adult females or males, and adult males spent the most time alert. Time alert varied among brood rearing areas and increased with brood size, but there was no variation in time spent alert among years. Increases in feeding or alert behaviors were at a cost to time spent in all other behaviors. We suggest that there is not a simple trade-off between feeding and alert behavior in cacklers, but instead that time spent feeding and alert are optimized against all other behaviors. We suggest that forage quality and availability determines the amount of time spent feeding, whereas the threat of predation or disturbance determines the amount of time spent alert.