“Pandemic in wild birds”: Avian influenza threatens seabird populations

‘Pandemic in wild birds’
Avian influenza threatens seabird populations

The consequences of the bird flu outbreak for ornithologists are unambiguous. It is not yet possible to predict how many seabirds have died. But experts now fear the whole species. The pathogen is harmless to humans – at the moment.

Dead birds, abandoned nests, hungry little animals: This year, bird flu is leaving particularly grim pictures in its wake — and at an unusual time. The infection process “has a completely new quality,” says the head of the National Avian Influenza Reference Laboratory at the Friedrich Loeffler Institute (FLI) near Greifswald.

Tim Harder assumes that tens of thousands of birds have fallen victim to the virus in the North Sea alone. A large summer wave caught colonies of seabirds. Terns are particularly affected in the North Sea, but are also affected by pelagic birds such as the gannet. In the Baltic it is found mainly cormorants, but also black-headed gulls. There was a massive spread of infection not only in the German region from the North and Baltic Seas, but also in the British Isles and in Scandinavia to Iceland. As well as outside Europe. “All of North America is also overwhelmed by this virus.” One could speak of a real pandemic in wild birds, Harder says.

According to Martin Römmler, bird protection consultant at Naturschutzbund Deutschland (Nabu), bird flu is threatening at least the population, if not the occurrence of entire species in Germany. “It definitely has potential.” The northern hemp bird, which breeds in Germany only in Helgoland, is called. “This means that if the colony dies, the species will become extinct for Germany.” He points to estimates by the local Jordsand Bird Conservation Society, which say 70 to 80 percent of nests there have been prematurely abandoned this year.

Precise surveys are difficult. According to Rummler, mother animals often die on the way, for example when they are looking for food. You can only assess the consequences in the next year. “When you see how many adults have come back, how many are starting to breed again.”

Unique infection process

According to Harder, Schleswig-Holstein and Lower Saxony were particularly affected in Germany in the summer. In Mecklenburg-Vorpommern there has been less evidence of recent times. Due to bird migration, outbreaks have occurred in the past, especially from October to April. In the summer of 2021, there were only isolated cases. An infection of the size of this summer was first observed.

Can this epidemic be contained? The expert is pessimistic. Infected carcasses can be collected quickly to prevent further infection. But: “The virus certainly can no longer be contained in this way.” Hopefully, less-lethal forms of the virus will prevail in the future. So far, however, there have been no signs of that. “In this respect, of course, such an epidemic will also end if no host is left susceptible.” This can be the case if there are not enough animals left or they have developed immunity. However, there is still no reliable information about this.

After all, according to Harder, the current virus is harmless to humans. He knows of only two infections in humans: one from England and one from the USA, both of which are not seriously ill. “But what should warn us is the number of cases in mammals with this particular virus.” Foxes, hens, otters, and most recently a black bear have all died. In close contact, there is also a risk of infection fatal to mammals. Therefore, ornithologists will have to protect themselves accordingly.

Europe at a turning point

In the past, there have also been deaths among humans – especially in Southeast Asia or Egypt. However, it was a different type of virus than the one that is currently prevalent. More than 2,000 people have been infected, of whom about 30 percent have died. Although human-to-human infections are very rare exceptions, there is significant concern that these pathogens can also cause epidemics in humans. There are certainly similarities with the coronavirus here.

The first precursor to the bird flu virus, which is still rampant today, was discovered in China in 1996 — in domestic poultry, Harder says. The way poultry is raised and traded in Asia, for example in live animal markets, has created niches and pathways for the spread of new influenza viruses.

Rommler advocated the abandonment of factory farming. Certainly large holdings should not be located near protected areas or known resting places for birds. Global monitoring of the infection process and the international exchange of information must also be improved. “Even at the EU level, it is not easy to get useful data.”

Hardy sees Europe at a turning point when it comes to bird flu. There have been so many outbreaks in the production of French ducks and Bulgarian geese “that you can no longer control them in the tried and tested way”. That is why one would consider allowing vaccination in Europe as well – as it is possible in some Asian countries. High control and financial costs speak against this. In addition, the virus is pressured to change. German producers have already received inquiries about vaccinations. I think that will certainly be discussed more intensively in the coming months and years.

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