Nesting Colonies

an aggregation of birds at a breeding site; an example of symbiosis, in which birds of one or several species nest close to one another.

Nesting colonies are characteristic of many groups of birds, including weaverbirds, rooks, certain swallows, bee eaters, herons, cormorants, seagulls, terns, auks, penguins, and petrels. Marine birds have the largest nesting colonies: auks in the arctic and northern Pacific Ocean, penguins and petrels in the antarctic, and cormorants and gannets near the coast of South America. (In South America the bird droppings, or guano, are gathered and used as fertilizer.) In the USSR large nesting colonies are found on the shores of northern seas (auks and seagulls form so-called bird bazaars there), in the Volga delta, and in Transcaucasia (massive breeding sites of herons and other species). To maintain and enlarge reserves of valuable bird species, the territories of many nesting colonies have been designated as sanctuaries.