Dozens of bald eagles have died from bird flu

With millions of chickens on commercial poultry farms infected and dying from a highly virulent strain of bird flu in recent months, you may have escaped noticing that some of the country’s most surprising wild birds have also contracted the virus.

The virus has taken an extraordinary toll among birds of prey or raptors, including more than 36 bald eagles. Since spring is nesting season, some experts worry that bird flu could pose a serious threat to the birds’ potential offspring.

In Minneapolis, a beloved family of great-horned owls living on the shores of Lake Nokomis has died of bird flu. In Florida, black eagles were injured. And in Georgia, three injured bald eagles were found dead in coastal counties.

The H5N1 strain of the highly pathogenic avian influenza virus, widespread in Europe, was first reported in North America in the Canadian province of Newfoundland and Labrador in December 2021. By mid-January, the virus had infected an American pigeon and blue-winged teal in South Carolina, according to the South Carolina Department of State. American agriculture.

Waterfowl, a natural incubator for bird flu, have been particularly affected. The 763 reported wild bird infestations, according to the USDA, include snow geese in North and South Dakota, northern scoops in North Carolina, brown pelicans in Florida, wild ducks in Minnesota and many unknown ducks in Ohio.

Bald eagles hunt live prey and excavate carcasses, providing a potential route for transmission of the virus. “If waterfowl are dying, vultures can pick them up from eating those dead waterfowl,” said Kristen Schuller, co-director of the Cornell Wildlife Health Laboratory.

The USDA said it has reported 41 bald eagles have died from the virus since February, a number that does not include the two other bald eagles that Schuller confirmed infected in New York in late March. This month, bald eagles have been infected in Ohio, South Dakota, Illinois, Wisconsin, Vermont, Maine and North Dakota.

Bald eagles have long been considered a conservation success story. The population was nearly extinct due to the synthetic insecticide DDT: in 1963, there were only 417 known nesting pairs. But decades of conservation efforts, combined with the 1972 ban on DDT, allowed the species to recover and was eventually removed from Endangered Species Act protections in 2007.

Despite this recoil, many bald eagles suffer from chronic lead poisoning. Since the birds search for hunted carcasses, they can ingest lead from ammunition, according to a paper published this year in the journal Science. This widespread, long-term exposure has confirmed the resilience of bald eagle populations, according to a study published this year by Schuler and colleagues in the Journal of Wildlife Management.

New threats to these species, such as wind turbines or a strain of bird flu, may threaten their long-term success. “The resilience of these animals was very close to the edge,” Schuller said. “If only a few breeding adults die, it could have a very large impact on the future growth of these populations.”

It is not yet clear how bird flu will affect the species’ recovery. “I am concerned that it will be endemic, and there are already reports of some recombination, which means there is a new strain mixing with some of the North American versions that we have and producing new viruses,” Schuller said. “We’re always worried about those.”

But the virus appears likely to compromise nesting success — the nest’s ability to produce at least one small bird capable of flight — among certain populations this year, according to a statement from the Georgia Department of Natural Resources. Aerial surveys of bald eagles nesting in six coastal counties in Georgia have revealed that nest success is down 30% this year, according to the statement.

Some wild birds with bird flu may not show any symptoms, but the infection can also lead to neurological problems, which can make it difficult for the bird to fly or correct itself. At Back to the Wild, a rehabilitation center in Ohio, bald eagles believed to have contracted bird flu appear to be unstable on their feet and unable to fly. Some even had epileptic fits.

“Everyone is admitted with the same symptoms and they die within hours of admission,” said Heather Tuttle, the center’s director of education, adding that the admission rate had begun to slow. Of the dozens who were brought to the center, none survived. There is no effective treatment.

Bird flu does not pose a significant threat to people, and no cases of H5N1 bird flu have been reported in the United States, according to the Centers for Disease Control and Prevention. People should avoid direct contact with wild birds and their faeces, and hunters should avoid harvesting or handling sick or dead wild birds. Hunters should also wash their hands with soap and water after touching game birds and cooking meat to an internal temperature of 165 degrees Fahrenheit.

Some experts have advised people to take down bird feeders to reduce the spread of H5N1 virus in wild birds. But Schuller has not seen many birds that use feeders, such as songbirds, infected with the virus. “So this does not appear to be a major source of potential transmission,” she said.

But bird feeders can still spread other pathogens and parasites, such as the bacteria that cause house sparrow’s eye disease, so it’s still important to keep them clean.

Instead, Schuller suggests keeping vigil about the spread of bird flu and reporting any unusual deaths or birds that appear to have neurological problems. “The better data we have about what’s really going on, the more we can find out,” she said.

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