What future for common terns such as these two juveniles taking a breather during migration to Africa?
THE bird flu that has devastated seabird colonies on the British and other European coasts is now taking its toll on the other side of the Atlantic.
According to the fopremost American bird conservation organisation, the Audubon Society, early casualties have included several tern species, with victims compulsively shaking their head - a symptom of neurological issues associated with highly pathogenic avian influenza (HPAI)
Scientists have been tracking the current strain of HPAI in North America since December 2021 when the first case was detected in Canada.
It remains unclear exactly how the pathogen arrived, but genetic analysis has shown that the North American strain is descended directly from the European strain.
"Based on the experience that the European countries have had, it looks like it's not necessarily going to slow down anytime soon," says Samantha Gibbs, the lead wildlife veterinarian at the U.S. Fish and Wildlife Service. "They’ve been dealing with it for a couple of years now at least, and it’s not just going away."
Terns have been among the hardest-hit species in recent outbreaks. More than 1,000 Caspian terns on Wisconsin’s Lake Michigan coast have died since late May, with testing identifying HPAI as the cause.
In the Netherlands, where the current European strain has been circulating since 2016, the virus’s impact on Sandwich terns has been catastrophic.
Thousands of birds across multiple colonies have perished during the breeding season, with one colony of more than 7,000 birds being completely wiped out earlier this month.
A research site in Germany, meanwhile, is documenting an exponential spike in deaths during an ongoing outbreak at the Banter See that has killed hundreds of common terns.
Because common terns frequently move around between colonies, a disease outbreak at one colony can quickly spread to others.
Meanwhile, it is feared that An HPAI outbreak in Maine, New England, could spell catastrophe for the likes of puffins, Arctic terns, least terns and endangered roseate terns.
Researchers are keeping a particular close eye on the puffins whose historic Maine populations were re-established in the late 1970s by Steve Kress, the founder of Project Puffin and former executive director of Audubon’s Seabird Restoration Program.
Matters are only made worse by the fact that scientists are helpless to treat sick birds.
Instead, they say that the best way to support bird populations during avian flu outbreaks is to reduce outside stressors.
While a healthy, resilient population can withstand disturbances from disease, a population stressed by factors like habitat loss, decreased food supply or pollution will have a harder time rebounding.
No comments:
Post a Comment