State reports bird flu outbreak in geese at two southwest Iowa lakes

The Iowa Department of Natural Resources confirmed Thursday that Canada geese at two southern Iowa lakes tested positive for highly pathogenic avian influenza.

The outbreak was detected following reports of dead geese at Green Valley Lake, near Creston.

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Rachel Ruden, the state wildlife veterinarian with DNR, said this is the first time mass mortality events from the bird flu have impacted southwest Iowa since the start of the HPAI outbreak in 2022.

“We’ve been kind of buffered in southwest from seeing great activity,” Ruden said. “Whereas other parts of the state, central Iowa and northeast, it’s been pretty routine to get activity in the fall (and) winter.”

Since 2022, according to national data from U.S. Department of Agriculture, more than 184 million domestic poultry have died from the virus, and more than 8,500 cases of the flu have been detected in wild birds.

According to DNR, staff received reports of dead geese at Green Valley Lake Dec. 11 and began collecting birds to submit for testing at Iowa State University’s Veterinary Diagnostic Lab. Results from the test revealed geese died from the H5N1 avian influenza.

Ruden said reports of dead geese circulated around the same time for Lake of Three Fires, in Bedford, where the other documented outbreak occurred.

Because the birds are wild, can sink in the water or be taken off by scavenging animals, Ruden said it’s difficult to gather an exact count of the number of dead birds during an outbreak. She said last year, wild bird deaths across the state totaled in the low thousands. So far, in southwestern Iowa where the outbreaks have been concentrated this winter, Ruden estimated bird deaths totaled a “couple hundred.”

Canada geese migration increased in late November with the cold and snowy conditions across Iowa. According to DNR, a Dec. 12 survey of waterfowl found the Canada geese populations had increased by more than 30 percent from the week prior.

DNR said it’s “uncertain” how long the outbreak will last, but staff expect waterfowl will “disperse” and therefore reduce opportunities for transmission, as rain and mild weather move in.

Ruden said it will be interesting, from a scientific perspective, to see how the scavenging population in southwest Iowa reacts to the outbreak. In the past, she said, there has been a concern about bald eagles contracting bird flu after scavenging bird carcasses but as it turns out, many of the mature bald eagles have shown they have antibodies to avian influenza.

“But, that might not hold true in the southwest, where they really haven’t seen the same level of exposure,” Ruden said.

People should avoid contact with dead or sick birds, according to DNR and to the U.S. Centers for Disease Control and Prevention. While the public health risk of HPAI is low, there have been more than 70 cases of the virus in people who were exposed to sick poultry or dairy cattle.

DNR also advises Iowans keep their pets from dead or sick birds as they can also get sick from the virus.

Iowans who see 20 or more bird carcasses are encouraged to call their local wildlife staff, a directory of which can be found online.

The state has additional guidelines for Iowans who find a bird carcass on their property and want to collect and dispose of it safely.

“We encourage the public to report sick birds or other wildlife to your local wildlife biologist or conservation officer to help us track impacts of this disease,” Ruden said in the news release. “We all have a part to play in keeping Iowa’s wildlife healthy.”

This article was first published by Iowa Capital Dispatch.