USE OF WINTER BIRD FEEDERS BY BLACK-CAPPED CHICKADEES

Bird feeding is widespread and a frequent component of urban wildlife management; however, no data on how individuals use the resource or what it contributes to their energy needs are available. Consequently, we studied the foraging behavior of 348 color-banded black-capped chickadees (Parus atricapillus) at winter bird feeders in Wisconsin, from 1983 to 1985. Chickadees obtained approximately 21% of their daily energy requirements from the feeder. Individuals with home ranges close to the feeder used it more heavily (P < 0.001) than those with home ranges at greater distances. The number of chickadees visiting the feeder and their feeding rate were higher (P < 0.001 and P < 0.025, respectively) prior to sunset than in the morning. Feeder use did not differ (P < 0.100) between males and females or adults and juveniles. Feeders were used the most in autumn and the least in spring, and ambient temperature had no effect (P > 0.200) on the use of feeders. Although chickadees depended primarily on natural food sources, feeders provided an important supplement to their natural diet.