With its distinct call, the noisy but shy hoiho is one of the world’s most endangered penguins. Despite valiant efforts over the past 30 years, the mainland population is disappearing before our very eyes.

Words Annie Studholme

Sporting their distinctive pale yellow headband and yellow eyes, the hoiho is found exclusively along New Zealand’s shores. Featured on our five-dollar note, it is the world’s fourth-largest penguin and the only surviving member of the genus Megadyptes. It gets its te reo Māori name, hoiho (noise shouter), from their shrill and piercing call. 

Unlike other penguins, hoiho are individualists, preferring their own company to colony living. They choose to nest in isolation, out of sight of their closest neighbour, commuting up to a kilometre inland to their lifelong nesting area. Most have the same mate for life with breeding season occurring from September to February. A clutch of two eggs is laid in September or October and hatches six weeks later. Both parents share the parenting.

Hoiho spend half their lives at sea. Each morning, they swim 2–25 kilometres out to sea to the edge of the continental shelf. They dive 200 times a day up to 140 metres deep, searching for food before returning to land, roosting in the same patch of coastal bush every night. Split into two distinct populations, the northern population breeds on the south coast of the South Island from Banks Peninsula to The Catlins and Stewart Island, while the larger southern population breeds on the subantarctic Auckland Island and Campbell Island.

Once abundant, scientists are warning that if there isn’t a massive turnaround, the hoiho will be locally extinct on the mainland in the next two decades. Nest counts from 2024–25 across Otago, Southland, and Stewart Island were substantially down on previous years, showing an ongoing decline of 80 per cent. In 2008–09, there were 739 nests, whereas last summer, they only found 143 nests.

But nest numbers are only part of the picture. Of higher concern is that there are currently less than 100 yellow-eyed penguin chicks on Stewart Island and mainland New Zealand, and of those, it’s expected that less than 20 individuals will survive to adulthood. As long-lived seabirds, hoiho have low reproductive and juvenile survival rates.

‘We are at a real tipping point,’ says Yellow-eyed Penguin Trust (YEPT) General Manager Anna Campbell, who was recently appointed to lead the organisation. ‘Nest and chick numbers are critically low on mainland New Zealand. This summer, we have some of the last-ever young yellow-eyed penguins in Aotearoa.’

If there isn’t a massive turnaround, the hoiho will be locally extinct on the mainland in the next two decades.

Hoiho have long captivated people’s attention. Dunedin schoolteacher and amateur ornithologist Lance Richdale studied them for more than 20 years, publishing two landmark books in the 1950s. Back then, numbers were substantial, but Otago Museum Assistant Director John Darby’s six-year population study in the 1980s told a different story. Predators and a lack of suitable breeding sites had decimated hoiho numbers.

In response, a group of conservationists proposed a radical single-species conservation initiative leading to the birth of the Yellow-eyed Penguin Trust in 1987, focusing on reforesting coastal ecosystems, predator control, research projects and establishing a plant nursery. Mainland came on board as principal sponsor in 1989, beaming the hoiho’s plight to television sets nationwide. With funds, public support and voluntary labour, the hoiho’s future looked secure – until now.

Though it’s easy to be disillusioned, Anna has not lost hope. She says the YEPT remains committed to a future where hoiho thrive in the natural environment. ‘Now is the time to come together and be bold and brave – collaborating can enhance our potential to protect the hoiho. We have to stay the course. We have to stay focused and do the work.’

The YEPT is working closely with the Department of Conservation (DOC), Te Rūnanga o Ngāi Tahu, and Fisheries New Zealand, as well as the Otago Peninsula Eco Restoration Alliance (OPERA), Forest and Bird NZ, Dunedin Wildlife Hospital, Penguin Rescue, and Penguin Place, along with local farmers, other community groups, and organisations, to develop place-based approaches.

In the face of waning resilience, declining mainland hoiho numbers have been linked to disease, introduced predators, human disturbance, a significant shift in adult diet, fisheries bycatch, and marine predation. ‘If we want to see the mainland population thrive again, we have to create a significant impact,’ says Anna. ‘With so few breeding pairs they are at a critical point of vulnerability. We must approach the recovery looking to resolve the underlying issues in the environment, particularly in the ocean.’ She’s excited about the new science and research coming through. ‘Sustainable transitions of industry, decarbonisation, and planting native trees are all making a difference. There is so much hope that we can create that tidal wave we need for hoiho, but we need to do it now,’ she says.