Avian flu killing waterfowl, raptors in Minnesota, Wisconsin, Dakotas
Hundreds of geese, ducks and eagles have perished already as migration moves north.
The new strain of highly pathogenic avian influenza that has forced the destruction of nearly 25 million domestic poultry across the U.S. is also spreading rapidly among wild bird populations in Minnesota, Wisconsin and the Dakotas.
The disease appears to have spread north quickly from states like North Carolina and Florida, riding in infected, migrating birds, especially waterfowl.
Minnesota already has seen multiple cases of Canada geese, mallard ducks and bald eagles with the disease, starting in late March and increasing this week.
In North and South Dakota, Iowa and Missouri, snow geese have died by the dozens. Snowy owls, hawks, swans, crows, vultures, cormorants, pelicans and other waterfowl have also perished, according to the U.S. Department of Agriculture.
More than 40 species of wild birds in 30 states have tested positive so far.
“This strain (of avian influenza) really seems to be devastating for wild birds, especially waterfowl and the critters that eat waterfowl," said Michelle Carstensen, wildlife health group leader and wildlife veterinarian for the Minnesota Department of Natural Resources.
Carstensen said wildlife health experts across the country and into Canada are getting daily reports on dead birds as the migration moves north. As of Thursday, Minnesota has seen 24 confirmed cases in wildlife in 10 counties.
“We don’t know yet what it is about this H5N1 strain that is making it spread in wildlife so fast. Back in 2015, when H5N2 really hit the poultry industry in Minnesota, we looked hard all across the state and just didn’t find any. We found it in one bird, a Cooper's Hawk. ... This is clearly a whole different situation now," Carstensen said. “This is a big wildlife health issue. … What impact it might have on wildlife populations, like will it reduce the goose population, we don’t know yet. It’s just getting started.”
No songbirds or wild turkeys, yet
While some wildlife experts have suggested homeowners take in their bird feeders to help prevent the spread of the disease among songbirds, so far not a single songbird has been reported with the disease in any state.
“For whatever reason, they (songbirds) just don’t seem to be susceptible to it," Carstensen said. “But it could happen.”
Wildlife health experts say wild birds can be infected with H5N1 and show no signs of illness. But some wild birds show neurological impacts from avian influenza, such as tremors or seizures, or become weak and unable to fly.
It’s believed that wild birds are the likely pathway for the disease to spread into domestic poultry, which has caused the destruction of millions of birds in Minnesota and Wisconsin, sending the price of eggs and chicken in grocery stores skyrocketing.
“And this time, we’re seeing it in backyard (poultry) flocks, unlike 2015, when we didn’t really see that at all," Carstensen noted. “Probably because it’s so rampant in waterfowl.”
So far, the disease also has spared upland birds, like wild turkeys and pheasants.
“Upland birds such as wild turkey have behaviors and prefer habitats that make them less likely to encounter avian influenza viruses in the wild," the Wisconsin Department of Natural Resources noted in announcing the disease had arrived in the state.
This is a big wildlife health issue. … What impact it might have on wildlife populations, like will it reduce the goose population, we don’t know yet. It’s just getting started.
Carstensen said the disease has not yet been found in wild turkeys in Minnesota, either, but that it would be possible. She’s asking spring wild turkey hunters to report dead turkeys, eagles or other birds they find, especially if they don’t show any obvious sign of trauma.
The most recent strain was confirmed in Europe last year, then in Newfoundland, Canada, and then quickly hit the southeast coast of the U.S., where many species of migrating birds spend the winter.
Human risk low
The Centers for Disease Control and Prevention says the risk to humans of contracting the disease is very low.
“Based on available epidemiologic and virologic information about these viruses, CDC believes that the risk to the general public’s health from current H5N1 bird flu viruses is low. However, some people may have job-related or recreational exposures to birds that put them at higher risk of infection," the CDC notes on its website. “Infected birds shed bird flu viruses in their saliva, mucus and feces. Bird flu infections among people are rare; however, human infections can happen when enough virus gets into a person’s eyes, nose or mouth, or is inhaled."
Cooking meat from wild game to a proper temperature, at least 165 degrees, would kill the virus in any poultry, experts note. The U.S. Department of Agriculture suggests hunters and anyone else handling wild birds wear rubber gloves while handling wild game as an added safety precaution.
Report dead birds
The Minnesota DNR asks that you report finding any group of dead birds in one location that have no obvious cause of death — or any sickly or dead waterfowl or raptors, such as eagles — to your local DNR wildlife office or by calling the DNR information center at 888-646-6367.
In Wisconsin, you can report dead or sickly birds to the DNR Wildlife Hotline by emailing firstname.lastname@example.org or by leaving a voicemail for a return phone call at 608-267-0866.
In North Dakota, dead birds can be reported at gf.nd.gov/wildlife/diseases/mortality-report.