With their yellow feather plumes and red bills crested penguins are the most elaborately adorned of the penguins. Some species also have striking red eyes. Comprising five species, Eudyptes is more diverse than the other penguin genera. All crested penguins are offshore foragers and migratory, leaving the colonies deserted during the non-breeding season.
All species display obligate brood reduction. That is, they lay two eggs but raise only a single chick. Typically, the surviving offspring is derived from the second egg, which, unlike other birds, is also much bigger than the first egg. In those species where two eggs hatch, hatching order is reversed from laying order: the chick from the second-laid egg hatches before the chick from the first egg.
During the breeding cycle, both partners must undergo extensive periods of fasting. Males, for example, often fast for over 40 days from arrival in the colony to their departure on the first foraging trip after egg laying. Incubation of the eggs is shared between the partners. After hatching, however, only the male broods the chick for about three weeks while the female provisions the chick.
Crested penguins are the most widespread genus of penguins, found throughout the sub-Antarctic, where they breed on just about any suitable island. The breeding range extends from the northern perimeter of the Antarctic to cold-temperate islands in the north. The species seem to be stratified on a north-south axis. A concentration of species is found around New Zealand where four out of the five species breed, three of which are endemic.
All crested penguins are migratory and highly seasonal breeders. Males generally arrive at the breeding colonies several days before the females. Egg laying is highly synchronised within a colony. Adults return to the colony for a post-nuptial moult.