Bird colony

A bird colony is used to refer to large aggregations of individuals of one or more species of bird that roost or nest in close proximity at a particular location.

The habit of nesting in groups is believed to provide better survival against predators due to the larger number of individuals available for defence as well as the ability to satiate predators. Colony-nesting birds often show synchrony in their breeding. [Picman, J., S. Pribil, and A. Isabelle. 2002. Antipredation value of colonial nesting in Yellow-headed Blackbirds. "Auk" 119:461-472.]

Nesting colonies are very common among seabirds on cliffs and islands. Many ground nesting birds nest in colonies. Herons, egrets, storks and other large waterbirds also nest communally in what are called "heronries". Colony nesting is considered as a response to shortage of safe nesting sites and abundance or unpredictable food sources which are far away from the nest sites. [Cecile Rolland, Etienne Danchin, Michelle de Fraipont 1998. The Evolution of Coloniality in Birds in Relation to Food, Habitat, Predation, and Life-History Traits: A Comparative Analysis. "The American Naturalist", Vol. 151, No. 6:514-529 ]

Communal bird roosts are similarly thought to provide greater security. Another suggestion is that roosting colonies act as information centers and birds are able to learn from others at the roost site about good foraging sites. [Ward P, Zahavi A, 1973. The importance of certain assemblages of birds as "information centers" for food finding. "Ibis" 115:517-534.]

Colony nesting birds are often used by humans as a source of eggs, food and guano.

Colony size is a major aspect of the social environment of colonial birds.

ee also

: Seabird colony

References