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.

Taxonomy

The yellow-eyed penguin was first described by Jacques Bernard Hombron and Honoré Jacquinot in 1841.

The yellow-eyed penguin is the sole species in the genus Megadyptes, though there have been multiple subspecies. It was previously thought closely related to the little penguin, but molecular research has shown it is more closely related to penguins of the genus Eudyptes. Mitochondrial and nuclear DNA evidence suggests it split from the ancestors of Eudyptes around 15 million years ago. In 2019 the 1.25Gb genome of the species was published as part of the Penguin Genome Consortium, aiming to understand the origins and aid conservation by helping to inform any future breeding programmes.

Subspecies

Megadyptes antipodes antipodes

The hoiho or yellow-eyed penguin (M. a. antipodes) is the only extant subspecies. They were formerly most abundant in the subantarctic Auckland and Campbell Islands, and colonised Stewart Island / Rakiura and parts of the South Island following the extinction of the Waitaha penguin.

There are proposals to split the yellow-eyed penguin into three further subspecies due to genetic differences. Genome sequencing of 249 penguins from across the New Zealand mainland and the subantarctic Enderby and Campbell Islands identified clear genetic divisions in each location with negligible gene flow between the populations, consistent with there being three distinct subspecies. Comparison of these genomes with DNA from two extinct subspecies showed that the three lineages diverged between 5,000 and 16,000 years ago.

Megadyptes antipodes waitaha

The Waitaha penguin (M. a. waitaha) is an extinct subspecies that was present in the North Island, and Codfish Island / Whenua Hou. Last dated to AD 1347–1529. scientists comparing the foot bones of 500-year-old, 100-year-old and modern specimens of penguins. According to lead researcher Sanne Boessenkool, Waitaha penguins "were around 10% smaller than the yellow-eyed penguin. The two species are very closely related, but we can't say if they had a yellow crown." The penguin was named for the Māori iwi (tribe) Waitaha, whose tribal lands included the areas the Waitaha penguin are thought to have inhabited. Archaeological remains indicate that early Polynesian settlers hunted the subspecies and that this, with possible additional predation by Polynesian rats and dogs, was a probable cause of extinction. It was first described as a new species M. waitaha in 2009, but reclassified as a subspecies M. a. waitaha in studies from 2019 and 2022. After their extinction, their range was occupied by yellow-eyed penguins (now M. a. antipodes), previously most abundant further south in the subantarctic islands. The decrease in sea lion populations after human settlement may also have eased their expansion. Another coauthor, Dr Phil Seddon, said "these unexpected results highlight ... the dynamic nature of ecosystem change, where the loss of one species may open up opportunities for the expansion of another."

Megadyptes antipodes richdalei

Richdale's penguin (M. a. richdalei) is an extinct island dwarf subspecies from the Chatham Islands. Its forehead, crown and the sides of its face are slate grey flecked with golden yellow. Its eye is yellow. It stands tall and weighs . 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 on average are somewhat heavier than females at an average of .

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. Jeremy Austin, a member of the team that discovered the Waitaha penguin, said, "Our findings demonstrate that yellow-eyed penguins on mainland New Zealand are not a declining remnant of a previous abundant population, but came from the subantarctic relatively recently and replaced the extinct Waitaha penguin."

An island dwarf subspecies from the Chatham Islands, M. a. richdalei, is extinct. The northern population extends along the southeast coast of the South Island of New Zealand, down to Stewart Island / Rakiura and Codfish Island / Whenua Hou. Based on monitoring between 2012-2017, there are on average 577 breeding pairs per year on Enderby Island in the Auckland Islands, which comprise 37-49% of the total breeding population for the species.

Behaviour

Breeding

thumbnail|A family of yellow-eyed penguin at the Penguin Place Lodge at [[Otago Peninsula, Dunedin, New Zealand]]

The nesting behaviour of yellow-eyed penguins is thought to be the least colonial of all penguin species. While other penguin species nest in large aggregations, yellow-eyed penguins tend to nest in solitary pairs or loose aggregations. Accordingly, the consensus among New Zealand penguin workers is to use habitat rather than colony to refer to areas where yellow-eyed penguins nest.

The species prefers to nest in forest or scrub habitat with dense vegetation cover. Adults will incorporate vegetation such as twigs, grasses and leaves into their nests, and often return to the same nesting area each year. Breeding sites are frequented year-round, and adults may continue to defend their nest areas outside of the breeding season.

Yellow-eyed penguins begin forming pairs and breeding at around two years of age. Nest site selection takes place from June onwards, with breeding beginning in late August, followed by incubation from September to November. Other species taken are New Zealand blueback sprat (Sprattus antipodum) and cephalopods such as arrow squid (Nototodarus sloanii). They also eat some crustaceans, including krill (Nyctiphanes australis). Recently, jellyfish were found to be targeted by the penguins. While initially thought that the birds would prey on jellyfish itself, deployments of camera loggers revealed that the penguins were going after juvenile fish and fish larvae associated with jellyfish.

Breeding penguins usually undertake two kinds of foraging trips: day trips where the birds leave at dawn and return in the evening ranging up to 25 km from their colonies, and shorter evening trips during which the birds are seldom away from their nest longer than four hours or range farther than 7 km. Yellow-eyed penguins are known to be an almost exclusive benthic forager that searches for prey along the seafloor. Accordingly, up to 90% of their dives are benthic dives. but can swim up to 240 meters below the water surface.

Conservation

thumb|Yellow-eyed penguins on [[Otago Peninsula]]

The yellow-eyed penguin is considered one of the rarest penguin species in the world. It is listed on the IUCN Red List as being endangered. It was first included on the list in 1988 when it was listed as threatened, and was changed to endangered in the year 2000.

Northern population

Around a third of the total yellow-eyed penguin population live on the mainland. Data from the Department of Conservation showed that the northern population had collapsed by 80 percent since 2008, from 739 breeding pairs to just 143 in 2025. Experts is likely that the group could disappear within the next 20 years if the trend continues. The last breeding-age female at Sandfly Bay died in 2024, after being caught in a set net, leaving the site functionally extinct.

Southern population

The subantarctic population, where the majority of the species breeds, is less studied. Monitoring of the 2015 to 2017 breeding seasons found that fledging success tended to be higher than on the mainland, although chicks were smaller and lighter on average.

Threats

thumb|upright|Penguin calling at [[Curio Bay, New Zealand]]

Populations of yellow-eyed penguins are threatened by multiple factors.

A risk assessment published in November 2025 indicated the biggest threats to the species are malnutrition, predation, disease, other trauma/unidentifiable sources, and fishing. Sea surface temperature has also been shown to influence the survival of both adults and fledglings.

The northern population is declining as a result of recurring poor breeding seasons and ongoing high adult mortality. Threats at sea include poor foraging success, and becoming caught in fisheries equipment. Chicks are often lost at sea, with only 20% projected to make it back to land for nesting, and only 5% expected to breed.

Studies carried out during the 1980s showed that red cod is a key part of their diet, however red cod populations have since declined, and more recent investigation has found that the penguins are feeding on blue cod instead, which provide less suitable nutrition. A similar problem has affected the Stewart Island population.

In 2023, a novel Gyrovirus was identified as the likely cause of the mysterious and fatal respiratory illness The disease has a mortality rate of more than 90%. It was estimated in 2023 around 320 individuals died.

Mitigations

A reserve protecting more than 10% of the mainland population was established at Long Point in the Catlins in November 2007 by the Department of Conservation and the Yellow-eyed Penguin Trust. The species was granted protection under the U.S. Endangered Species Act in 2010.

Due to extreme disease outbreak and subsequent mortalities, the Dunedin Wildlife Hospital began treating chicks with disease symptoms or weight loss. The following year, the hospital hand-reared 214 chicks, as it was estimated that 50 to 70% of chicks would have died without intervention. Later that year the ban was extended by another nine months. The closure extended the existing four nautical mile set net ban, which was in place to protect dolphins, out to eight nautical miles. The ban came after urgent calls from conservation groups as the species entered their breeding season. The extension applied to waters surrounding the Otago Peninsula, leaving habitats including North Otago and Stewart Island unprotected. In the same ruling, the court recognised that the temporary emergency closure is lawful, and that ministers must work to safeguard the species’ survival.

Tourism

Several mainland habitats have hides and are relatively accessible for those wishing to watch the birds come ashore. These include beaches at Oamaru, the Moeraki lighthouse, a number of beaches near Dunedin, and the Catlins. In addition, commercial tourist operations on Otago Peninsula also provide hides to view yellow-eyed penguins. However, the yellow-eyed penguin cannot be found in zoos because it will not reproduce in captivity.

Impact of human presence

Research has indicated that the presence of humans in their coast habitat can negatively influence the behaviour of yellow-eyed penguins. The transit time for individual penguins to move from land to sea is increased when people are nearby, and around a fifth of transits are abandoned when a human is present. When people are present on an area of beach near penguin landing sites, the penguins are less likely to come ashore. This behaviour has potential implications for chick survival; probability of survival is correlated with fledgling weight, and the influences from humans preventing adults from coming ashore may lead to reduced fledgling success.

In culture

  • The hoiho appears on the reverse side of the New Zealand five-dollar note.
  • The yellow-eyed penguin is the mascot to Dunedin City Council's recycling and solid waste management campaign.
  • The yellow-eyed penguin is also featured in Farce of the Penguins, in which they complain about global warming.
  • In 2019 the yellow-eyed penguin was crowned the Bird of the Year in New Zealand, the first win for a seabird in the competition's 14-year history. It was again victorious in the 2024 competition.

See also

  • Fauna of New Zealand
  • List of extinct New Zealand animals
  • List of birds of New Zealand

References

  • BBC Science and nature page about Megadyptes waitaha
  • Official Yellow-eyed Penguin Trust site in New Zealand
  • Yellow-eyed penguin on PenguinWorld
  • Yellow-eyed penguins from the International Penguin Conservation website