Bird Flu's Impact on Wild Birds and Backyard Feeders

Bird flu has been a significant issue for poultry and dairy farms across the United States since it first appeared in North America in late 2021. This outbreak has led to a sharp increase in egg prices. But how has it affected wild birds? More than 170 different species of North American wild birds, including ducks, geese, gulls, owls, and eagles, have been infected with the virus. The impact on these birds has been severe, with over 12, 000 individual birds testing positive for the virus. However, this number is likely much lower than the actual count, as most dead birds are not tested. Many wild birds can carry the virus without showing symptoms. For example, dabbling ducks like mallards and blue-winged teal can carry the virus with few signs of illness. This is because these viruses have co-evolved with waterfowl. Unfortunately, these ducks can still spread the virus through their feces or saliva, potentially infecting other birds or even mammals like foxes. Birds that migrate or roost in large groups, such as geese and seabirds, are particularly vulnerable to large-scale outbreaks. A recent outbreak among migratory eared grebes in Utah resulted in the deaths of thousands of birds. Songbirds, which are commonly seen at bird feeders, can also get infected and die. However, their populations seem to fare better because they do not gather in large groups where the virus can easily spread. Symptoms of bird flu in wild birds can vary but often include lack of coordination, inability to fly, and respiratory distress. If someone spots a wild bird acting strangely, it is best to call a local wildlife rehabilitator and avoid handling the bird directly. If handling is necessary, wearing gloves and a mask is advised.

Bird feeders are generally considered safe and do not significantly contribute to the spread of bird flu. However, if someone also keeps backyard chickens, it is recommended to take down the bird feeder to prevent potential transmission to the poultry. Regular cleaning of bird feeders and nesting boxes is also important. The risk of bird flu spreading to people from bird feeders is very low. For endangered species like the California condor, scientists have organized vaccination programs, but this is not feasible for most wild bird species. Instead, protecting habitats and reducing other risks, such as exposure to pesticides or lead ammunition, is crucial. Bald eagles, which are federally protected but no longer endangered, have also been affected. They often eat dead animals, which can be infected with the virus. During the first year of the outbreak, many eagles died, likely from eating infected ducks or bringing them to their nests. Additionally, there was a high number of eagle chicks that did not survive into adulthood, possibly due to the virus or sick parents. However, the number of confirmed infections in eagles has declined over time, suggesting that surviving eagles may have acquired some immunity. This past migration season, researchers counted a record number of bald eagles migrating through northern Minnesota, indicating a hopeful rebound in the eagle population.

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