New threats to the species, such as wind turbines or a strain of bird flu, could threaten its long-term success. “The resilience of these animals was very close to the limit,” Schuler said. “If a few more breeding adults died, it could really have a big impact on the future growth of these populations.”
It is still unclear how this bird flu will affect the species’ recovery. “I’m worried that it’s endemic, and there have already been reports of some recombination, which means there’s this new strain mixing with some of the North American versions that we have and creating new viruses,” Schuler said. “We always worry about that.”
But it looks like the virus will undermine nest success — the ability of a nest to produce at least one young bird capable of flight — among certain populations this year, according to a statement from the Georgia Department of Natural Resources. Aerial nesting surveys of bald eagles in six coastal Georgia counties revealed nesting success has dropped by 30% this year, according to the statement.
Some wild birds infected with avian flu may have no symptoms, but the infection can also lead to neurological problems, which can make it difficult for a bird to fly or right itself. At Back to the Wild, a rehabilitation center in Ohio, bald eagles believed to have bird flu appear unsteady on their feet and are unable to fly; some even had seizures.
“They all come in with the same symptoms and die within hours of admission,” said Heather Tuttle, the center’s director of education, adding that the admission rate has started to decline. Of the twelve brought to the center, none survived. There is no effective treatment.
Bird flu poses little threat to people, and no cases of H5N1 bird flu infection 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 droppings, and hunters should avoid picking up or handling wild birds that are sick or found dead. Hunters should also wash their hands with soap and water after touching game birds and cook the 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 in wild birds. But Dr. Schuler has not seen many feeder birds, such as songbirds, infected with the virus. “So it doesn’t look like this is a major source of potential transmission,” she said.