Communal roosting

Communal roosting is an animal behavior where a group of individuals, typically of the same species, congregate in an area for a few hours based on an external signal and will return to the same site with the reappearance of the signal. Environmental signals are often responsible for this grouping, including nightfall, high tide, or rainfall. The distinction between communal roosting and cooperative breeding is the absence of chicks in communal roosts. While communal roosting is generally observed in birds, the behavior has also been seen in bats, primates, and insects. The size of these roosts can measure in the thousands to millions of individuals, especially among avian species.

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