A mysterious disease is ravaging chicks of New Zealand’s endangered yellow-eyed penguins, but scientists say they may have found the cause.
These endemic birds of New Zealand, unable to fly, barely reach human knees. They have pale yellow eyes and a strip of yellow feathers around the head.
There are about 2,400 specimens left alive, according to New Zealand Department of Conservation estimates.
They are classified at the country’s highest alert level: “threatened, of national danger.”
The mysterious respiratory disease that attacked them first appeared in 20 cats at the Dunedin veterinary hospital in 2019.
“They can’t lift their heads and are gasping for glassy eyes,” hospital director Lisa Argilla told AFP this week.
“It’s sad to see those little chicks in critical condition,” explained the veterinarian.
“All the calves that showed respiratory symptoms died. We couldn’t do anything to save them,” he added.
During the 2020 breeding season, a third of the 150 chicks sent to the hospital also died due to respiratory problems, this veterinarian explained.
Professor Jemma Geoghegan, an evolutionary virologist, is part of a team of specialists investigating this disease.
“The veterinary hospital is doing everything in its power to prevent it, but without knowing the cause it is very difficult to manage,” he said.
Scientists analyzed tissue samples from dead chicks with sequencing technology similar to that used to identify the coronavirus that causes Covid-19.
“There are two diseases that we are investigating and we have found two viruses that we believe are likely to be responsible,” said the Otago University professor.
His team identified a new gyrovirus and a new megrivirus, he said.
These two diseases would have killed about 25% of yellow-eyed penguin chicks (about 50 per year) in recent breeding seasons, according to Geoghegan.
“We know what we think might be the cause and a lot of research is needed now to find out if we can prevent or treat the disease,” he explained.
Currently, they take the puppies less than five days old to the Dunedin Veterinary Hospital, where they can be raised from the risk of infection.
By 2022, veterinarians were able to return 90% of the chicks alive to their nests, Director Argilla said.
“142 chicks received a second chance,” he said. “If they had stayed in the nest, most would have contracted one of the diseases and died.”
The director of the clinic said that raising so many chicks, with a group of 10 people to guarantee the animals five meals a day, is a “crazy operation.”
Vets, nurses, zookeepers and conservation officers from all over New Zealand helped them, he said.
Penguins live in two colonies: one in the southwest of the country’s South Island and one larger in the remote subantarctic islands of New Zealand.
The population of the first of the colonies has fallen by 75% since 2008, with only 200 breeding pairs, and is in danger of disappearing within two decades, experts warn.
Not everyone is the cause of these infections. Climate change or predators such as sea barracudas or dogs, cats, ferrets or stoats also cause damage.
Argilla hopes to find a vaccine to protect these animals.
“We are an ambulance at the bottom of the hill doing our bit to save the birds and, with a little luck, stop the population decline,” he said.
