Territorial during the breeding season, chickadees flock during the rest of the year. Small flocks made up of several adult pairs and unrelated juveniles are commonly seen from late summer through winter. Flocks of chickadees sometimes cross paths with kinglets, creepers, nuthatches and downy woodpeckers and form temporary associations.
Chickadees are specially adapted to endure Alaska's rugged winters. They have much denser, better-insulating plumage than other songbirds their size and a special ability to put on fat quickly. Birds burn fat as fuel to keep themselves warm in winter. A chickadee can put on eight percent of their body weight in fat each day. Chickadees are also able to drop their body temperature at night in order to conserve their winter fuel.