Definition:

(adjective) Describes a bird species that is sociable and forms large flocks. Many bird species form flocks for foraging, roosting or breeding, including communal flocks at nesting colonies where all chicks may be raised together. Migration is another time when large flocks form in bird species that may otherwise be more solitary.

Gregarious behavior is beneficial to birds because it provides protection in numbers and gives each individual a better opportunity for survival, such as a roosting flock generating body warmth in cold weather or a foraging flock having more birds to find food or watch for predators.


Some species may form these large flocks throughout the year, while others only form large flocks in certain seasons, the most frequent being in late summer after the breeding season ends. The size of the flock can vary from a few dozen birds to thousands of individuals, and personal space within the flock also varies. The composition of the flock may be a single species or may include several bird species with similar needs, such as mixed flocks of waterfowl or sparrows.

Bird species well known as gregarious include European starlings, red-winged blackbirds, emperor penguins and many types of ducks, geese and other waterfowl.

See Also: Names of Groups of Birds

Photo – American Coot Flock © Bruce Tuten

Pronunciation:

grih-GAIR-eee-us

Also Known As:

Social, Sociable