What to know about the bird flu outbreak in wild birds and what it means for backyard bird feeders

WASHINGTON (news agencies) — Bird flu has devastated poultry and dairy farms, and sent the price of eggs soaring in the United States since it was first detected in North America in late 2021.

But what has been the toll on wild birds? More than 170 species of North American wild birds – including ducks, geese, gulls, owls, eagles and others – have been infected with bird flu.

Take precautions around sick or dead wild birds, experts recommend. But you can keep your bird feeder up. Despite the spread in birds and other wild animals, scientists say the threat to the general population is currently low.

More than 12,000 individual birds have tested positive since the virus began spreading, according to the U.S. Agriculture Department.

The count is a “gross underestimate” because most dead birds are never taken to a lab for testing, said Bryan Richards at the U.S. Geological Survey’s National Wildlife Health Center in in Madison, Wisconsin.

Dabbling ducks, such as mallards and blue-winged teal, can carry the virus with few symptoms because “these viruses co-evolved in waterfowl,” said Richards. But ducks can also shed the virus in their feces or saliva, sometimes infecting other birds or mammals like foxes.

Birds without natural immunity that migrate or roost together in large flocks, such as geese, are most likely to die in large numbers. A recent bird flu outbreak among migratory eared grebes in Utah killed between 15,000 and 25,000 birds near Great Salt Lake, state wildlife officials said in early February.

Seabirds, which tend to roost in large numbers, are also highly impacted.