World’s rarest penguin suffers disease, starvation and selfies

By Tracy Brighten
Human settlement pushes New Zealand’s yellow-eyed penguin to the brink
Yellow-eyed penguin and chick

Yellow-eyed penguin feeding chick at Penguin Place, Otago. Image credit: David Brighten

The Emperor penguin is arguably the most familiar penguin in the world, the poster penguin for climate change as global warming melts the Antarctic ice they depend on. Indeed, this magnificent penguin’s survival in such an inhospitable environment is well-reported in films and documentaries such as March with the Penguins and the BBC’s Dynasties.

But not all penguins live in sub-zero temperatures. The yellow-eyed penguin is challenged by temperatures at the other extreme, yet the plight of this ‘Endangered’ IUCN Red List Threatened Species is less widely known. 

Experts believe the yellow-eyed penguin is the oldest of seventeen species living today, unique among penguins for its solitary behaviour as well as its forest-dwelling habits. Native and endemic to New Zealand, the yellow-eyed penguin is immortalised on the nation’s five dollar note, the significance of which may soon become apparent for one of the rarest penguins in the world.

Yellow-eyed penguin forest habitat

The yellow-eyed penguin (Megadyptes antipodes) breeds on the southeast coast of the South Island in only four regions—Banks Peninsula (near Christchurch), North Otago, Otago Peninsula (near Dunedin), and the Catlins—as well as on Stewart Island and adjacent islands, and on sub-Antarctic Auckland and Campbell Islands.

Breeding sites used by the yellow-eyed penguin today were once coastal hardwood forests. Millions of years ago, these gentle, solitary penguins enjoyed the cool protective sanctuary of a forest canopy that stretched the length of South Island’s east coast.

To survive the icy sea, penguins are insulated by fat, but on land, the yellow-eyed penguin needs protection from New Zealand’s tropical heat and storms. The forest provided plenty of weatherproof nest sites as well as protection for chicks against seabird attacks.

With no other predators stealing their eggs and chicks, New Zealand’s forests were abundant with these unusual penguins. The ground-dwelling kiwi and kakapo, the latter now critically endangered, flourished alongside the yellow-eyed penguin in a forested paradise.

Maori and European arrival destroyed coastal forests

This peaceful existence came to an end 700 years ago when Maori settlers arrived in canoes from Polynesia, bringing with them rats and dogs. They burned coastal forests to create settlements and hunted species such as the moa to extinction. European settlers arrived around 200 years ago and continued the habitat destruction. They burned vast forests to create farmland, destroying birdlife and changing the landscape dramatically in the process.

Penguins were forced to nest further inland where adults, eggs and chicks became easier prey for non-native cats and dogs as well as for stoats, which were introduced by European settlers to control the soaring rabbit populations they had created. Today, feral cats are even found off the mainland on Stewart, Auckland, and Campbell Islands; livestock is also an ongoing problem for penguins. Grazing cattle, sheep and goats trample their nests and hinder scrub regeneration.

Conservation groups restoring habitat  

Although this shy bird doesn’t attract anything like the government and public attention the iconic kiwi enjoys, collaborative effort is underway to save the yellow-eyed penguin. The Department of Conservation (DoC), the Yellow-Eyed Penguin Trust, Forest and Bird, Penguin Place, and Penguin Rescue, along with scientists, community groups and private landowners have joined forces. Their conservation work includes restoring coastal forest and scrub, fencing off nesting sites from livestock, providing nesting boxes, controlling predators, and treating sick and injured birds. But like the yellow-eyed penguin’s return journey from sea to nest, it’s an uphill struggle fraught with setbacks.

Sharp decline in yellow-eyed penguin breeding pairs

DoC has reported a sharp decline in penguin nesting numbers counted in South Island’s Otago and Southland regions, down from 491 breeding pairs in 2012 to around 160 counted by the end of 2015, with the final total not expected to exceed 190 breeding pairs.

Yellow-Eyed Penguin Trust General Manager Sue Murray is concerned that repeated poor breeding seasons have major management implications. Conservation group staff and volunteers are exceptionally busy during spring and summer months, regularly checking beaches for distressed birds, as well as monitoring nest sites.

Yellow-eyed penguin

Yellow-eyed penguin viewed from the hide at Penguin Place, Otago. Image Credit: David Brighten

Populations have suffered devastating events over the last few years, including:

  • unexplained deaths thought to be caused by a toxic marine-based pollutant
  • widespread starvation in adults, juveniles and chicks
  • higher incidence of barracouta attacks
  • avian diphtheria in chicks
Mass mortality from marine biotoxin

In early 2013, a mass mortality event thought to be a marine biotoxin claimed the lives of over 70 adult and juvenile penguins on the Otago Peninsula. With limited funding for tests, DoC and Massey University have been unable to identify the toxin.

Widespread penguin starvation

Later that year, the breeding season was one of the worst witnessed by DoC rangers as penguins were found emaciated by starvation. A recurring El Nino climate pattern causes warm ocean temperatures, which affects the food chain and reduces food availability for penguins.

During times of food scarcity, adults can only feed one chick. Adult penguins were coming home and not feeding their chicks, so rescue groups appealed to fisheries to help supplementary feeding by supplying fish. Penguin Place doubled the size of their hospital to feed around 100 penguins a year for the third year in a row. Lack of food causes delayed breeding, so late developing chicks are given supplementary feeding to ease the pressure on adults as they approach moulting. However, starving chicks receiving supplementary feeding are prone to infection and may still die.

Rise in barracouta attacks  

In March 2015, 77 penguins needed rehabilitation in Otago after suspected barracouta attacks. This year, the Yellow-Eyed Penguin Trust took no chances and Wellington Zoo veterinary science manager Dr Lisa Argilla was on site in Otago to treat and rehabilitate injured penguins. The timing coincided with the onset of moulting. Before they moult, penguins need to be in optimum health with extra fat reserves because they are land bound for 24 days while they replace old feathers.

Outbreaks of avian diphtheria in chicks

First seen in 1999, avian diphtheria affects up to 90 percent of chicks on the Otago Peninsula in alternate years. The disease causes mouth ulcers that severely restrict feeding and breathing. DoC and conservation groups provide treatment and supplementary feeding to reduce chick mortality. DoC is working with Massey University’s Wildbase wildlife hospital to identify the source of the disease. Even before avian diphtheria joined the list of threats, only 19 percent of chicks fledged. Juvenile penguins are now a rare sighting.

Habitat loss leaves adults and chicks vulnerable

Yellow-eyed penguin mating pairs build a nest of twigs, grass and leaves in patches of forest or dense vegetation where they can find a hollow secluded from other penguin nests. Two eggs are usually laid within a few days of each other and parents share incubation, chick guarding and feeding. As well as avian diphtheria, chicks fall victim to heat stress, human disturbance, trampling by livestock, and predation by feral cats, dogs, ferrets and stoats. Parents are ill-equipped to fight off these vicious non-native predators. When chicks are six weeks old, they are left alone while both parents go to sea in search of food. Yellow-eyed penguin chicks don’t have the safety in numbers that penguins living in colonies can rely on.

Adult penguins are at risk of dog attacks during their long trek from sea to nest, which involves crossing open pasture. With inadequate forest protection, penguins are also vulnerable to heat stress when they are on land, which accounts for more than half the time for adult penguins. At sea, yellow-eyed penguins are preyed on by sharks, sea lions, and seals, leopard seals in particular. The death of a parent in the post guard stage means one chick will die. A single parent cannot feed two chicks until they begin to feed themselves, which is from four months of age.

Impact of commercial and recreational fishing

Penguins are also at risk from non-targeted fishing methods such as gill nets, which entangle them and cause drowning. Conservation groups are calling for an extension to the set net ban zone, out to the 25 km mark, the extent of the penguin’s feeding range. Such a ban would also benefit Maui and Hector’s dolphins, New Zealand fur seals and diving seabirds, but a powerful fishing lobby has so far prevented any extension.

Yellow-eyed penguins feed mainly on squid, as well as sprat, red cod, opal fish, silversides and blue cod, although there is no firm evidence that fisheries directly affect feeding opportunities. Reduced food supply impacts adult health, breeding, chick rearing, fledging weights and chick survival.

Yellow-eyed penguin on rocks

Yellow-eyed penguins at Sandfly Bay, Otago. Image credit: David Brighten

Easy to recognise but difficult to see

Around 60 cm tall, the yellow-eyed penguin takes its common name from pale yellow eyes, unique to this species. Its Maori name is hoiho, or ‘noise shouter’, because of its unmistakable range of calls and trills. With white chest and belly, slate blue back and tail, pink feet, and a distinctive yellow band crowning its head, the yellow-eyed penguin is easily identifiable. But you’ll have to be eagle-eyed and quiet as a mouse. These penguins are rare and if you do spot one, these shy birds don’t respond well to human disturbance, so you could unknowingly affect breeding and chick-rearing behaviour.

Impact of human disturbance   

Penguin Rescue, a rehabilitation centre in North Otago, is highly concerned about the impact of unregulated visitors on yellow-eyed penguin breeding and survival. Signs and viewing hides are erected to benefit visitors and protect wildlife, but visitors often ignore signs. Visitors block penguin access between nests and the sea at Katiki Point. They also ignore signs put up by Penguin Rescue at Katiki reserve detailing opening and closing times. Tourists still arrive after dark, climbing gates and fences.

Based on a laser-operated counter, Penguin Rescue estimated 40,000 to 50,000 visitors to Katiki in the five-month breeding period in 2014/2015. Visiting is further concentrated by tourist information advising the best time to view is two hours before close when penguins are returning from a day at sea to feed their hungry chicks. Penguins are wary of returning to their nest if they feel threatened. It seems that people are given priority over penguins in places with unregulated access.

Box-ticking tourists like free attractions

Penguin Rescue also report that many visitors come to see penguins at Katiki Point because it’s free and they can do it quickly. This box-ticking attitude is further demonstrated by people getting very close to penguins to take selfies for sharing on Instagram. These tourists have no regard for penguin welfare, or for the dedicated work by conservationists who help this endangered species survive, as well as providing a haven for other seabird species.

Penguin Rescue has documented the impact of human disturbance on the breeding success at Katiki Point where visitor access is high and unregulated. In the 2014/2015 breeding season, the number of fledged chicks at Katiki was half the number at a nearby colony without public access, and fledged chick weights were also lower, affecting chick survival chances and future breeding. Visitors can have a significant negative impact on yellow-eyed penguin survival if they are not mindful of the penguin’s needs. By learning more about wildlife beforehand, we enrich our own experience and help to protect animals for future people to enjoy.

A rare gem that needs our protection

If you’re familiar with the Otago Peninsula, you might know the hide at the far end of Sandfly Bay where I was first enchanted by yellow-eyed penguins. If you’ve been there at dawn you will have seen these sprightly penguins zigzagging down rocky slopes to the sea, and you will know how unique and special they are. If you’ve been to ‘Penguin Place’ at sunset and run through tunnels linking hides as you follow a solitary penguin from the beach through dunes to meet its chick, you will know. But you don’t need to see to know. I’m sure I’ll never see an Emperor penguin in the Antarctic, but just knowing they are there is reason enough to care.

How can we help the endangered yellow-eyed penguin?

  • Consider donating to the Yellow-Eyed Penguin Trust, Penguin Place and Penguin Rescue
  • When visiting wildlife reserves, be aware of rules, restrictions and recommendations
  • Keep dogs on a leash in areas of wildlife concern
  • Dispose of plastic rubbish safely
  • When fishing, avoid using indiscriminate fishing methods such as gill nets
  • Only buy fish caught using sustainable methods with no bycatch or unsustainable fish stock depletion
  • Sign petitions to urge the NZ government to restrict or regulate visitor access and to fund penguin conservation

Also published on Wildlife Articles

Image credits:
Yellow-eyed penguin feeding chick by David Brighten (taken from a hide at Penguin Place, Otago Peninsula)
Yellow-eyed penguin in pasture by David Brighten (taken from a hide at Penguin Place, Otago Peninsula)
Yellow-eyed penguins on rocks at dawn by David Brighten (taken from a hide at Sandfly Bay, Otago Peninsula)

The Hoiho New Zealand’s Yellow-Eyed Penguin. Adele Vernon. Hodder & Stoughton. New Zealand. 1991.