Meet the rarest penguin in the world and find out what we can do to help it survive
The Hoiho
About the hoiho or yellow-eyed penguin
Hoiho is the Māori name for the yellow-eyed penguin. Yellow-eyed penguins are endemic to New Zealand. They are found on the south island of New Zealand and on a few sub-Antarctic islands. It is the rarest penguin species in the world. During the last 20 years the population declined by about 75%! On the mainland of New Zealand, there are less than 500 individuals left (status 2023). The rest of the hoiho live on New Zealand’s sub-Antarctic islands. In total, there are about 1500 hoiho left in the world.
Update from 7. June 2024: According to recent counts, there were only 163 breeding pairs in the 2023/24 breeding season on the mainland of NZ (including Stewart Island). That’s a decline by 17% compared to the 2022/23 season, when 196 pairs were counted. Despite the conservation effort, the numbers are rapidly declining. According to rangers from the department of conservation “there are no signs of recovery”. In the Catlins region the population dropped by 37% from 2021 to 2023, on the Otago peninsula by 17% and on Stewart Island by 30%. According to the rangers the hoiho could be gone by 2050…
Hoiho means “noise shouter”, due to its shrill call. In contrast to other penguin species, yellow-eyed penguins are shy and not social. They prefer to nest away from others. Reaching a body size up to 78 cm, the hoiho is one of the taller penguin species. Adults have a band of yellow feathers around their eyes and the back of their head, as you can see in the photo on the right.
Their favoured prey are small fish and arrow squid. To catch it, the penguins swim up to 25 km offshore and dive up to 200 times to the seafloor to catch their prey.
Habitat
Yellow-eyed penguins live in native coastal forests or scrub of the south-east coast of the South Island of NZ, Stewart Island, sub-Antarctic Auckland Islands and Campbell Island. Hoiho carefully chose their nesting sites in the vegetation, looking for a solid back and protection from weather and sun. Nesting sites are found along beaches with sand or pebbles or rock platforms.
The photos show the different beaches, where the hoiho lives – from sandy to rocky beaches.
A hoiho on its way to his chicks. If you look closely, you can see the other parent waiting in front of the nesting site in the top right corner of the image.
Threats
There are several threats on land and at sea that the hoiho are facing.
Climate Change
One threat for hoiho is climate change. With rising temperatures the ocean temperatures are also rapidly rising. Warmer sea water is less nutrient dense, resulting in fewer fish, the main food source of the penguins. In the last years, the sea water in their habitat was up to 6 degrees (!) warmer than normal, negatively impacting the fish populations. Thus, yellow-eyed penguins need to swim even further out to the sea to find enough food. But more swimming means also more calories burned, leading to many adults and chicks suffering from malnutrition. According to a study from 2017, sea surface temperatures are a dominating factor influencing survival of yellow-eyed penguins.
Fishing Industries
It is estimated that each year on average 44 (!) hoiho die in fishing nets. Especially set nets are a deadly trap for them. Additionally fisheries can impact the availability of fish for the penguins, contributing to their malnutrition. In 2023, New Zealand established six new marines reserves around the southeast coast of the South Island. Let’s hope they can help to hoiho to survive.
Habitat Destruction
Many native coastal forests were cleared or fragmented to make place for farming. However, hoiho can adapt and are partially able to successfully breed in the new environment. Besides the loss of the coastal forests, large grazing animals like cows in the habitat of the penguins can pose a threat by trampling nests and even birds.
Two adults with their two chicks. The adult hoiho on the left just returned from the ocean and is now feeding a chick. Update: One of the parents died in summer 2024, about 8 months after this photo, due to injuries sustained by fishing boats.
Predation
There were no land mammals (except for bats) in New Zealand before settlers arrived on the islands. With the settlers came rats, stoats, cats and other land-based predators. As the native species in NZ were not used to such predators, they struggled with their appearance on the islands. Land-based predators are a major threat for many bird species in NZ. Rats, stoats and ferrets can eat penguin eggs or kill the chicks. There are also records of dogs killing adults or chicks. Even pigs can be a threat. There are New Zealand wide efforts to protect native wildlife by killing invasive mammals using traps. The government aims to get rid of all invasive predators in New Zealand by 2050. In areas without predator control, the hoiho chick mortality can be as high as 60%.
Human Disturbance
Yellow-eyed penguins are very susceptible to disturbance. This threat is very location-dependent, as some nesting sites are closed to public. Human disturbance (even just standing at the beach) can prevent the hoiho from leaving the water and feeding the chicks. Studies show that human disturbance increases stress, and reduces breeding success, fledgling weight and the probability of survival. So if you are at a beach where hoiho nest, follow the local rules and do not disturb the birds.
Disease
There are several diseases effecting hoiho. Avian diphtheria is a disease which commonly affects young chicks, whereas avian malaria affects adults as well. Every year there are deaths from avian malaria. Alone in the season 2018/19 there were 29 confirmed hoiho deaths caused by the disease. Birds can be more susceptible to disease if they are stressed (environmentally or nutritionally) and their immune system is suppressed.
Disease has the potential to become a bigger issue in the future as the climate warms, and as human disturbance and stress on the penguin population increases. A big threat for the survival of the hoiho is the bird flu, that is currently spreading all around the world. An outbreak in New Zealand could be potential fatal for the yellow-eyed penguin.
Behind the scenes
During my travel in New Zealand, I have visited a rehabilitation center for yellow-eyed penguins close to Dunedin. It is operated by the OPERA (https://theopera.co.nz). Here, they treat sick, injured or malnourished penguins. On average they take care of over 250 hoiho per year – that is more than half of the population on the mainland. Sadly some penguins even end up in rehab three times or more within a year. Once the treated penguins are healthy again, they are released back into the wild.
At a public beach with hoiho nesting sites, I met two volunteers who helped to keep people in a safe distance from the nests to minimise disturbance. They also educated people about the penguins and told me that 10 years ago this beach was a popular nesting site for yellow-eyed penguins, with more than ten nesting penguins pairs distributed across the beach. Now, in late 2023, there was only one pair with two chicks and one single adult left.
It really amazed me to watch the hoiho walk up steep sand dunes and hop from rock to rock to reach its nest. At one site, the penguins needed to scale roughly 40 to 50 meters of altitude on a sandy and steep hill to get to their chicks – all with their short legs.
Photographing yellow-eyed penguins is not easy and needs time. I was there during chick season. During that time of year, hoiho can return from the ocean pretty much any time of the day. Normally one parent leaves the nesting site around sunrise and heads to the ocean to get food. So a good time to hopefully see one is around sunrise. Another good time is the late afternoon to sunset, when the penguins return from their last food run before it gets dark. However, you never really know when they show up, so you have to spent quite some time at the beach and wait. Despite not having too much time and some bad weather I had some luck and had a few awesome encounters with hoiho. In total I saw 6 different adult yellow-eyed penguins and two chicks in the wild, plus one adult, one juvenile and about 7 chicks in the rehab center.
A hoiho on its way to the ocean.
What you can do
There are some NGOs that try to help the hoiho to survive. They are doing a great work and are putting a lot of effort in to help the yellow-eyed penguins. You can support them by donating or volunteering, if you are in the area. Here is a list of some organisations:
https://www.yellow-eyedpenguin.org.nz
https://www.forestandbird.org.nz
If you ever travel to the South Island of New Zealand, make sure to follow the rules to not disturb the penguins. All of my photos were take from a great distance with a tele photo lens and were cropped afterwards. In addition I always tried to stay low and out of sight of the penguins. Please be responsible when trying to photograph or observe the hoiho. If you are in the area of Dunedin, visit the OPERA (https://theopera.co.nz). There you can learn more about the yellow-eyed penguin, visit the rehab center and hopefully see some penguins in the wild.
As you learned above, the fishing industries are one of the threats the hoiho is facing. Therefore you could help by eating less fish and seafood and more importantly, pay attention to how and where the fish is caught. Overfishing and bycatch is a major threat to many sea species, from fish to whales, turtles and birds like penguins. Look for sustainability certifications and inform yourself what kind of fish is sustainable to eat in your country (this can differ from country to country). Lastly, you can support incentives to protect more parts of the ocean.
Climate change is also a threat. By reducing your carbon footprint, you can also help the hoiho. There are many ways to do that, from eating less meat and dairy to buying less or using the public transportation instead of your car. Last but not least, voting for parties that try to fight climate change and protect the environment is a major action you can take.
Spread the word and tell other people about the hoiho and the threats it is facing. People can only protect what they know. :)
A hoiho chick in the rehab center.
A trap used to kill invasive predators.
What’s next
I only got to spent four days with the hoiho in 2023 and I am hoping to return to New Zealand within in the next two to three years to continue this project. I will keep you update, so stay tuned.
Below are a few more photos, enjoy. :)
