Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed and the number of genera is disputed. The great cormorant and the common shag are the only two species of the family commonly encountered on the British Isles and "cormorant" and "shag" appellations have been later assigned to different species in the family somewhat haphazardly.
