The avian flu outbreak that killed thousands of cormorants on the Cape West Coast and devastated chicken farms has spread to the penguin colony in Simon’s Town.
The public has been advised not to approach, touch or handle seabirds around Simon’s Town to prevent the spread of the highly infectious H5N1 avian flu virus among African penguins at Boulders Beach. More than 10 penguins there have died in a colony that is already declining from other causes.
“Avian influenza is a highly contagious viral disease, almost always fatal,” said Dr David Roberts, clinical veterinarian for avian coastal conservation foundation Sanccob, which has been assessing the colony.
“African penguins are endangered and, from a conservation point of view, it’s very scary.”
There are about 3,000 penguins in the Boulders Beach colony – 1,000 breeding pairs and the rest are youngsters.
Sick penguins look sick. They hunch up, seem depressed, their eyes can be crusty, they can stagger, twitch, fall over and have seizures. Roberts has been training SANParks rangers to spot the signs.
Bird flu spreads between both wild and domesticated birds. There’s no cure and no preventive treatment. Birds that fall ill have to be removed and euthanised.
Western Cape Minister of Environmental Affairs, Anton Bredell, said that while avian flu held almost no risk to humans, if transmitted from wild seabirds to poultry flocks, it could pose a great risk to the agricultural sector.
Low risk to humans
Although human-to-human transmission is infrequent, it has been passed from birds to humans in close contact with poultry or other birds. The World Health Organization, which has been struggling with zoonic (animal-to-human) transmission of Covid-19, has warned that a genetic mutation of H5N1 could increase the risk to humans.
In 2017, Sanccob noted that avian flu was spreading southwards through Africa. In 2018 it was detected in swift terns and several other species. Then, in 2021, as South Africa staggered under the pandemic, it hit chicken farms, leading to import bans against the poultry industry, massive culls and a huge loss of income.
Read more in Daily Maverick: “Thousands of endangered seabirds killed by H5N1 avian influenza outbreak”
That year, it also appeared on Dyer Island, De Mond and the Berg River on the Cape coast, resulting in the deaths of more than 24,000 Cape cormorants and Cape gannets. At the peak of the outbreak, the death rate was 700 a day.
Cape cormorants feed in flocks, sometimes of thousands of birds. Their long lines or V-shaped flocks are a feature of the West Coast. Besides the flu epidemic, overfishing of their main food, pilchards and anchovies, has put a strain on the species, which is endemic to the area.
The cormorant population has dropped by 50% in the past 50 years. Before the epidemic, there were an estimated 57,000 breeding pairs in South Africa.
“With only a few penguins affected at Boulders, the impact is minimal at present, but it could rise dramatically,” said Roberts.
“It’s transmitted through close contact, and penguins do get close and personal. Density plays a big role, as with Covid. The virus can survive in anything wet (but not seawater).
“If a sick bird has been sitting under a bush and another one goes there, transmission is possible. We worry about them all close together. They do interact and it can cause an outbreak.”
The cause of the H5N1 avian virus, as with Covid, is human food production and from the same part of the world, China. It most likely evolved in artificial poultry production systems and spread across the Far East, then Europe.
“The circulation of H5N1 has a strong link to commercial farming,” said Roberts. “Now it’s spilled over into wild birds. We have large numbers of birds dying, including endangered species that are affected in much bigger numbers than we’ve ever had before.”
“Every few years a different variant emerges. We don’t know how these new diseases work or what they will do. They seem to be scarier and have potential long-term population events. And with African penguins, you have an endangered species facing so many other threats.”
According to Table Mountain National Park, the Boulders colony will not be closed to visitors, but the public is asked to stay on the designated boardwalks and report any sick-looking or dead birds to park management on 021 786 2329/021 780 9100, Sanccob on 021 557 6155 or the penguin rangers on 064 844 9075. DM/OBP
Original article: https://www.dailymaverick.co.za/article/2022-09-20-deadly-avian-flu-hits-endangered-penguin-colony-on-cape-peninsula/