A large, thick-necked black-and-white marine shag endemic to the Marlborough Sounds of New Zealand. Shows pink feet, a distinct white patch on the wings, and a blue eye-ring. Breeding adults have yellow, warty caruncles on either side of the bill. Very wary of humans and boats. Juvenile birds have dull brown upperparts and light facial skin. Similar to the Pied Shag, but white facial feathers remain below the bill; the Pied Shag has a predominantly white face that reaches the eye and a slimmer neck. Stewart Island and Chatham Islands Shag are very similar, but the three do not overlap in range.