Yellow-eyed penguin

The yellow-eyed penguin (Megadyptes antipodes), known also as hoiho, is a species of penguin endemic to New Zealand. It is the sole extant species in the genus Megadyptes, from Ancient Greek μέγας (mégas), meaning "large", and δύπτης (dúptes), meaning "diver".

Previously thought closely related to the little penguin (Eudyptula minor), molecular research has shown it more closely related to penguins of the genus Eudyptes. Like most penguins, it is mainly piscivorous.

The species breeds along the eastern and south-eastern coastlines of the South Island of New Zealand, as well as Stewart Island, Auckland Islands, and Campbell Islands. Colonies on the Otago Peninsula are a popular tourist venue, where visitors may closely observe penguins from hides, trenches, or tunnels.

On the New Zealand mainland, the species has experienced a significant decline over the past 20 years. On the Otago Peninsula, numbers have dropped by 75% since the mid-1990s and population trends indicate the possibility of extirpation from the peninsula in the next 20 to 40 years. While the effect of rising ocean temperatures is still being studied, an infectious outbreak in the mid-2000s played a large role in the drop. Human activities at sea (fisheries, pollution) may have an equal if not greater influence on the species' downward trend.

The yellow-eyed penguin (M. a. antipodes) is most easily identified by the band of pale yellow feathers surrounding its eyes and encircling the back of its head. Its forehead, crown and the sides of its face are slate grey flecked with golden yellow. Its eye is yellow. The foreneck and sides of the head are light brown. The back and tail are slate blue-black. Its chest, stomach, thighs and the underside of its flippers are white in colour. Juvenile birds have a greyer head with no yellow band around their eyes.

It is the largest living penguin to breed on the mainland of New Zealand and the fourth or fifth heaviest living penguin by body mass. It stands 62–79 centimetres (24–31 in) tall and weighs 3–8.5 kilograms (6.6–18.7 lb). Weight varies throughout the year, with penguins being heaviest just before moulting, during which they may lose 3–4 kilograms in weight. Males at around 5.53 kg (12.2 lb) on average are somewhat heavier than females at an average of 5.13 kg (11.3 lb).

The yellow-eyed penguin may be long lived, with some individuals reaching 20 years of age. Males are generally longer lived than females, leading to a sex ratio of 2:1 around the age of 10–12 years.

The yellow-eyed penguin is mostly silent. It makes a shrill bray-like call at nest and breeding sites.