Description wikipedia

The Chatham Islands shag (Leucocarbo onslowi), also known as the Chatham shag, is a species of bird in the cormorant and shag family, Phalacrocoracidae. It is endemic to the Chatham Islands of New Zealand. For a long time the species was placed in the genus Phalacrocorax; today it is mostly placed with the other blue-eyed shags of New Zealand and Antarctica in the genus Leucocarbo. Its closest relative is the Otago shag of South Island. This is a large, pied shag with a long crest. It is highly coastal, rarely foraging far from shore, although sometimes feeds in the large and brackish Te Whanga Lagoon. It forages for fish and cephalopods and roosts on rocky shores. The species is colonial, breeding in small colonies around the Chatham Islands. Little is known about its breeding behaviour. The species is threatened by introduced predators, disturbance at its breeding colonies and habitat loss.