Temperature effects on foraging behaviour in Black-chapped Chickadees

Optimal foraging model hypothesizes that birds will attempt to maintain energy reserves by 1) minimizing expenditure and 2) maximizing input to compensate for energy spent producing heat. Birds should prefer high fat, low handling foods in the morning, especially after cold nights. In winter months these predictions were examined with free ranging black-capped chickadees (Parus atricapillus). High fat foods were favoured but now low handling types, supporting only one of the model's predictions. Food eaten following cold nights was both high in fat and low in handling; morning and afternoon consumption differences were nonsignificant. A longer study including more birds may provide results pertaining to time of day interactions.