Bird cliffs are steep cliffs with numerous small shelves which serve as nest

Nest

A nest is a place of refuge to hold an animal's eggs or provide a place to live or raise offspring. They are usually made of some organic material such as twigs, grass, and leaves; or may simply be a depression in the ground, or a hole in a tree, rock or building...

ing locations for bird colonies

Bird colony

A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...

. Bird cliffs are found on islands in the North Atlantic and Arctic

Arctic

The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

, such as the Faroe Islands

Faroe Islands

The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...

, the Svalbard

Svalbard

Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...

 archipelago and on islands off Northern Norway. Among species that nest in large numbers on bird cliffs are Common Murre, Thick-billed Murre, Razorbill

Razorbill

The Razorbill is colonial seabird that will only come to land in order to breed. It is the largest living member of the Auk family. This agile bird will choose only one partner for life and females will lay one egg per year. Razorbills will nest along coastal cliffs in enclosed or slightly exposed...

, Kittiwake

Black-legged Kittiwake

The Black-legged Kittiwake is a seabird species in the gull family Laridae.This species was first described by Linnaeus in his Systema naturae in 1758 as Larus tridactylus....

, Little Auk

Little Auk

The Little Auk, or Dovekie , is a small auk, the only member of the genus Alle. It breeds on islands in the high Arctic. There are two subspecies: A. a. alle breeds in Greenland, Iceland, Novaya Zemlya and Spitsbergen, and A. a...

 and Atlantic Puffin

Atlantic Puffin

The Atlantic Puffin is a seabird species in the auk family. It is a pelagic bird that feeds primarily by diving for fish, but also eats other sea creatures, such as squid and crustaceans. Its most obvious characteristic during the breeding season is its brightly coloured bill...

. The number of breeding couples may exhibit large variations depending on available food. Bird cliffs have often been exploited as a food resouce by the local population, as well as being used by hunters and egg collectors.