This large seabird has a predominantly white body and a dark grey back. Young birds have a shadowy grey nape which fades to white with age. Its wings, which span over a massive two meters, are dark grey on top, and white with a black border underneath (4). Its brow is dark-grey or black, giving the appearance of a constant frown. The feet are a bluey-greybill, and adults have a grey bill with a yellow tip, whilst juveniles have a greyish bill with a black tip (2) (4).