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A rookery is a colony of breeding animals, generally birds. A rookery is generally reserved for a colony of gregarious birds. 
Rook nest colony – rookery
While the term rookery may have come from the nesting habits of rooks, it is not reserved for corvids. Rooks – northern-European and central-Asian members of the crow family – nest in prominent colonies (multiple nests) at the tops of trees.
The breeding grounds of colony-forming seabirds and marine mammals (true seals or sea lions) and even some turtles are also referred to as rookeries.
The term "rookery" was also borrowed as a name for dense slum housing in nineteenth-century cities, especially in London.
Paleontological evidence points to the existence of rookery-like colonies in the pterosaur Pterodaustro.