The sulphur-yellow crest starts at the base of the base of the bill, extends over the eye and droops down the back of the head. The bill is very robust, particularly in the male, and the prominent area of bare skin at its base helps distinguish the Snares from the Fiordland penguin. The Snares may also have some white cheek feathers, however this occurs only in a few individuals and they do not form lines as in the Fiordland penguin. The eye is red, but not not as bright as seen in the Rockhopper. Sexes alike, but male is slightly larger and with a heavier bill.
Fledglings have pale chins and short crests.
Olearia lyalli and Brachyglottis stewartiae . The penguins nest in dense colonies of up to 1500 pairs, usually with at least part of the colony under vegetation. Because their activity kills the trees and shrubs around them, the colonies slowly move to adjacent vegetated areas and old areas quickly revegetate. The males return to the breeding sites in August. While a few pairs occasionally raise both chicks successfully, many pairs lose an egg during incubation and should two eggs hatch, one chick usually dies before the end of the guard stage.