Yellow-eyed penguins, known in New Zealand as hoiho, live only in southeastern New Zealand and on a handful of subantarctic islands hundreds of kilometers to the south. They are found nowhere else on Earth, making them one of the rarest penguin species in the world, with just 143 known nests on mainland New Zealand and Stewart Island as of the 2024/25 breeding season.
The Two Separate Populations
There are two distinct populations of hoiho, and movement between them is rare. The northern population lives on New Zealand’s South Island, stretching along the southeast coast from Banks Peninsula down to Bluff at the island’s southern tip, then across Foveaux Strait to Stewart Island (Rakiura) and its smaller neighboring islands, about 30 km offshore. The southern population lives much farther away on the subantarctic Auckland Islands and Campbell Island, roughly 480 km and 608 km south of the South Island respectively.
These two groups are essentially isolated from each other. They face different conditions, different levels of human disturbance, and their populations are tracked separately by New Zealand’s Department of Conservation.
Mainland and Stewart Island
On the South Island, the core habitat runs along the Otago and Southland coasts. The Otago Peninsula, near the city of Dunedin, is one of the most well-known areas for these penguins. Boulder Beach on the peninsula has been a long-term study site for researchers tracking the species. From there, breeding sites scatter southward through the Catlins, a rugged and relatively remote stretch of coastline at the bottom of the South Island.
Stewart Island and its outlying islands also support nesting pairs. These sites sit just across the strait from the mainland, giving the penguins access to productive coastal waters while offering somewhat less human disturbance than the mainland beaches.
This northern population is in serious trouble. In 1999, there were about 741 breeding pairs. By 2020, that number had dropped to 233. The most recent count, from the 2024/25 season, found only 143 nests, representing an 80% decline since 2008/09.
The Subantarctic Islands
The Auckland Islands and Campbell Island are remote, windswept, and largely uninhabited by people. These islands host the southern population, which appears more stable than its mainland counterpart, though it is far less closely monitored.
A 2017 survey estimated 570 breeding pairs on the Auckland Islands, a number consistent with an estimate of at least 520 pairs made back in 1989. Campbell Island had roughly 350 to 460 breeding pairs when last surveyed in 1992, but no recent count exists. The remoteness that makes these islands difficult to study also shields the penguins from many mainland threats like introduced predators and coastal development.
Where They Nest on Land
Unlike many penguin species that nest in open, densely packed colonies, yellow-eyed penguins prefer privacy. They nest in coastal forest, scrub, and dense vegetation, often choosing spots where they cannot see neighboring pairs. This preference for visual isolation means they need a surprising amount of vegetated coastal land to support even a small number of nests. Habitat loss from coastal forest clearing has been one of the pressures on mainland populations, because the penguins won’t simply crowd together in whatever space remains.
Where They Feed at Sea
Hoiho are not open-ocean travelers. They forage over the continental shelf, typically in water 40 to 80 meters deep. Research tracking penguins from Boulder Beach on the Otago Peninsula found that most birds are midshelf foragers, hunting 5 to 16 km from the coast. Some stay closer to shore, within 5 km, while others range out beyond 16 km. The median foraging trip lasted about 14 hours, covering 13 km from the breeding site, though some trips stretched as far as 57 km.
At Long Point, farther south along the coast, penguins foraged over slightly deeper water, between 80 and 120 meters, reflecting the different shape of the seafloor there. In all locations, the birds spread out across the flatter parts of the shelf rather than concentrating in one feeding area.
This reliance on relatively shallow coastal waters makes the penguins vulnerable to fishing activity, particularly setnet fishing, which can trap and drown them. Changes to the seafloor ecosystem and reductions in prey availability also affect them, especially on the mainland.
Why Their Range Is Shrinking
Yellow-eyed penguins are classified as Endangered by both the IUCN and New Zealand’s own threat classification system. The primary threats to the mainland population are fishing mortality (especially in setnets), habitat modification along the coast, and declining prey availability. Introduced predators like stoats, ferrets, and cats also kill chicks and adults at mainland nesting sites.
The 80% decline in mainland nests over the past 16 years means the species’ range is effectively contracting. Breeding sites that once held reliable populations now have few or no nesting pairs. The subantarctic populations, while apparently more stable, are so poorly monitored that any decline there could go undetected for years. The species now appears on New Zealand’s five-dollar note, a somewhat bittersweet distinction for a bird whose mainland population can be counted in the low hundreds.