Bird flu is killing alarming numbers of bald eagles and other wild birds, with many sick birds arriving at rehabilitation centers unsteady on their talons and unable to fly.
“It’s quite a sight to see an eagle with a wingspan of six feet having uncontrollable seizures from highly pathogenic avian influenza,” said Victoria Hall, executive director of the University of Minnesota Raptor Center. “At this point, they are so far into the disease that there are no more treatment options.”
The latest outbreak of the highly contagious virus has led to the culling of around 37 million chickens and turkeys on US farms since February, and the US Department of Agriculture has confirmed 956 cases of bird flu in wild birds, including at least 54 bald eagles. But the true number is likely much higher because not all wild birds that die are tested and the federal tally does not include cases recorded by wildlife rehabilitation centers.
The latest reported toll is nearly 10 times higher than the 99 confirmed cases in wild birds during the last bird flu outbreak in 2015. This time the virus was detected in birds in 34 states, indicating that ‘it is much more widespread than seven years ago. .
The US Geological Survey’s National Wildlife Health Center also collects data from wildlife officials on suspected and confirmed bird flu deaths. It lists 8,536 recent wild bird deaths from avian flu.
“This is certainly an unprecedented event,” said researcher Rebecca Poulson, who has studied bird flu for 15 years with the University of Georgia’s Southeastern Cooperative Wildlife Disease Study. “The number of birds, species and states already in which it has been detected is quite alarming.”
Waterfowl, including ducks and geese, which commonly carry the virus, and raptors and scavengers that feed on it are the birds most commonly ill, but cases have been confirmed in more than three dozen birds. ‘species. Ducks and geese are usually able to live with the virus without getting sick, but the latest variant is proving more contagious and deadlier.
“We’re seeing a huge impact from this virus,” said Hall, whose Raptor Center in St. Paul, Minnesota, treats about 1,000 birds a year. “We see birds arriving suffering from this virus every day.”
Nearly 61% of the 188 birds the rehabilitation center has tested since the end of March have had bird flu and all but one have died. Hall said the center should set up an area where workers wearing protective gear test sick and injured birds for bird flu and quarantine them before bringing them to the center, to avoid infecting others. birds.
None of the 114 positive cases recorded by the center, including 28 bald eagles, are included in the USDA tally, Hall said. She said a great horned owl had recovered from the virus, giving her hope that some wild birds might be able to fight it off.
USDA officials did not respond to questions about why they exclude data from rehabilitation centers.
Scientists estimated in a study published three years ago that the number of wild birds in North America had dropped by nearly 3 billion since 1970 as humans continued to encroach on their habitat. But it’s too early to know what impact bird flu will have on bird populations because the outbreak is ongoing and there hasn’t been enough time to study it, according to US Fish veterinarian Samantha Gibbs. and Wildlife Service, and other experts.
“We are quite worried. I think we’re going to be watching death rates very closely throughout the spring and summer,” Gibbs said.
Gibbs and Poulson said they fear the virus will survive the summer, when it typically dies, leading to infections in the fall when migrating birds return south. This happened in Europe, where the virus first circulates.
Bald eagles – the national symbol of the United States since the 1700s – are among the most famous conservation success stories in the United States. With an estimated 300,000 bald eagles in the country today – a population that has quadrupled between 2009 and 2021 – the bird was removed from the US endangered species list in 2007. Given this, the experts believe that the species should withstand the impact of this virus.
State and federal authorities will track the nesting success of eagles this spring and summer to assess the impact of the virus.
In Georgia, where three dead bald eagles tested positive for bird flu, the state Department of Natural Resources has documented a sharp decline in bald eagle breeding this year in six coastal counties where many migrating birds spend the winter. Less than half of the 73 nests found there produced offspring, while nests elsewhere in the state had a success rate close to the 78% average recorded in recent years.
Some experts, including Hall, suggest that residential bird feeders should be removed to prevent further spread of the virus, but the USDA and US Fish and Wildlife Service have not recommended this because bird flu is not common among songbirds that frequent backyards. . Still, they say it’s important to clean bird feeders regularly to help limit the spread of other diseases.
“Wild birds could use all the help they can get right now,” Hall said.
When the virus is detected in poultry farms, authorities cull entire flocks to curb the spread, even when most birds show no symptoms. So far, 37.36 million birds have been killed in 32 states.
USDA officials stress that bird flu does not compromise food safety because infected birds are not allowed to enter the food supply, and properly cooking poultry and eggs at 165 degrees Fahrenheit will kill all viruses or bacteria.
Health officials also say bird flu does not pose a significant health risk to people, even though a human case of the disease was confirmed in Colorado last month. Officials say people are unlikely to catch the virus unless they have direct and prolonged exposure to infected birds.
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