Rookery refers to particular natural areas where birds or marine animals gather for breeding.

Specific Habitats

A rookery usually means there's a significant number of animals nesting together, not just a few.

Large Colonies

Rookeries are most notable and active during the breeding season of the species.

Breeding Season

Using rookery for an urban area suggests extreme overcrowding and poor living conditions.

Poverty Implied

In history, rookeries referred to notorious slums, especially in places like 19th century London.

Historical Context

The term can carry a judgement, implying neglect by authorities or residents.

Negative Connotation

 Isla San Roque is an uninhabited bird rookery off Baja's sparsely populated central coast. Notice that the bottles here have caps on them. Bottles made of polyethylene terephthalate, PET, will sink in seawater and not make it this far from civilization. Also, the caps are produced in separate factories

Captain Charles Moore on...

 Cat Island it was actually one of the four largest rookeries in Louisiana for brown pelicans Snowy Egrets Roseate spoonbills least turns in a variety of