OMAHA, Neb. (AP) — Avian flu is killing an alarming number of bald eagles and other wild birds, and many sick birds arrive at rehabilitation centers unable to fly.
“It’s quite a sight to see an eagle with a six-foot wingspan go into uncontrollable seizures due to highly pathogenic avian influenza,” said Victoria Hall, executive director of the University of Minnesota Raptor Center. “At that point, they are so far along in the disease that there are no treatment options left.”
The latest outbreak of the highly contagious virus has led to the culling of about 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 to be significantly 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 number reported is almost 10 times higher than the 99 confirmed cases in wild birds during the last outbreak of bird flu in 2015. This time, the virus has been detected in birds in 34 states, indicating that it is much more widespread than seven years ago. .
The US Geological Survey’s National Center for Wildlife Health also collects data from wildlife officials on suspected and confirmed bird flu deaths. It lists 8,536 recent deaths of wild birds from avian influenza.
“This is definitely an unprecedented event,” said researcher Rebecca Poulson, who has been studying avian influenza for 15 years at the University of Georgia Southeast Cooperative Wildlife Disease Study. “The number of birds, species and states in which it has already been detected is quite alarming.”
Waterfowl, including ducks and geese, which usually spread the virus, and the birds of prey and scavengers that feed on them, are the most commonly sick birds, but cases have been confirmed in more than three dozen species. Ducks and geese can usually live with the virus without getting sick, but the latest variant is proving to be more contagious and deadly.
“We’re seeing a tremendous impact from this virus,” said Hall, whose Raptor Center in St. Paul, Minnesota, treats about 1,000 birds a year. “We are seeing birds suffering from this virus every day.”
Nearly 61% of the 188 birds the rehabilitation center has tested since late March have had bird flu, and all but one has died. Hall said the facility had to set up an area where workers wearing protective gear screen sick and injured birds for avian influenza and quarantine them before bringing them into the facility to avoid infecting other birds.
None of the 114 positive cases recorded by the center, including 28 bald eagles, are included in the USDA count, Hall said. He said a great horned owl has recovered from the virus, giving him hope that some wild birds might fight it off.
USDA officials have not responded to questions about why they are excluding data from rehab 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 continue to encroach on their habitat. But it’s too early to tell what impact bird flu will have on bird populations because the outbreak continues and there hasn’t been enough time to study it, according to Samantha Gibbs, a veterinarian with the US Fish and Wildlife Service, and others. experts.
“We are quite worried. I think we’re going to be looking very carefully at what the mortality rates are during the spring and summer,” Gibbs said.
Gibbs and Poulson said they fear the virus could survive the summer, when it usually dies off, leading to fall infections when migratory birds return south. That happened in Europe, where the virus is circulating first.
Bald eagles, the US national symbol since the 1700s, are among America’s most celebrated conservation success stories. With an estimated 300,000 bald eagles in the country today, a population that quadrupled between 2009 and 2021, the bird was removed from the US Endangered Species List in 2007. Given that, experts believe that the species should withstand the impact of this virus.
State and federal officials will track eagle nesting success this spring and summer to gauge the impact of the virus.
In Georgia, where three dead bald eagles have tested positive for bird flu, the state Department of Natural Resources has documented a sharp drop in bald eagle breeding this year in six coastal counties where many migratory birds spend the winter. Fewer than half of the 73 nests found there produced offspring, while nests in other parts of the state had a success rate close to the 78% average recorded in recent years.
Some experts, including Hall, suggest removing residential bird feeders 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 the songbirds that frequent backyards. . Still, they say it’s important to regularly clean bird feeders 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 found on poultry farms, officials cull entire flocks to slow the spread, even when most birds show no symptoms. So far, 37.36 million birds have died in 32 states.
USDA officials stress that bird flu does not endanger food safety because infected birds cannot enter the food supply, and properly cooking poultry and eggs to 165 degrees Fahrenheit will kill any viruses or bacteria.
Health officials also say bird flu does not pose a significant health risk to people, despite the fact that a human case of the disease was confirmed in Colorado last month. Officials say people are unlikely to contract the virus unless they have prolonged direct exposure to infected birds.
Associated Press writers Carrie Antlfinger in Milwaukee and Doug Glass in Minneapolis contributed to this report.
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