Bird flu claims dozens of geese and swans at Northern Iowa marsh

A Northern Iowa natural sanctuary increasingly looks like a graveyard as bird flu spreads through its waterfowl.

Sweet Marsh, a wetland northeast of Tripoli, welcomes Canada geese, trumpeter swans and dabbling ducks. However, these three types of birds are succumbing to bird flu at rapid rates.

Jason Auel, the wildlife management biologist who oversees Sweet Marsh, confirmed the disease earlier this month.

On Dec. 10, he noticed there were a few sickly geese. “Tuesday (Dec. 10) we didn’t notice any dead,” he said. “Wednesday (Dec. 11), there was 50 out there dead.”

This was about 10 percent of the current geese population at the marsh. The current death count is unknown.

Frequent Sweet Marsh visitor and wildlife photographer Kip Ladage ventured out to the marsh once he heard of the large number of dead birds. He goes out daily to document the sad sight and writes up what he finds on Facebook and YouTube.

In a post, he said he has never seen this level of bird flu in his lifetime, which is why he continues to watch and photograph the area.

At first, both Auel and Ladage witnessed dead geese. Then, the trumpeter swans followed.

“Eventually I saw a ‘young of the year’ trumpeter swan in the dying process — the first swan I saw affected by the outbreak,” Ladage said in a message to The Courier. “I expected I would eventually see dying and dead swans. I was not prepared for the first swan to die to be a young of the year.”

The baby swan, or cygnet, still having some of its gray fuzzy down, laid its long neck on the snow in front of him.

“It is heartbreaking to watch animals suffer, knowing you can do nothing and the situation will likely get worse,” he said. “I know we are seeing nature at its worst. In our ‘happy thought’ world, we dismiss that nature can be cruel. … This is nature happening in front of us. It is hard to watch, especially the swans.”

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The physical symptoms of this strain of bird flu are different from the beginning of the outbreak that started in 2022, said Rachel Ruden, the state wildlife veterinarian for the Iowa Department of Natural Resources. She said in 2022, it was more obvious when a bird was sick because it would have head or body tremors or seizure-like spasms.

But now, it isn’t as clear.

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“There’s a bunch of birds on shore and they aren’t seemingly ‘with it,’” she said. “Now people are concerned and want to bring them to (a rehabilitation center) because they don’t see what’s wrong with them. That’s a risk and makes it more difficult to limit human exposure because they want to help and don’t perceive it as how a sick animal would behave.”

Auel said the symptoms he’s seen in the marsh’s birds are lethargy, swimming in circles and not trying to stay warm.

Both he and Ruden said the abnormally warm winter weather isn’t helping. The birds congregate to keep the still water open and prevent ice from forming, which is easier than migrating.

“One of our concerns with the mild weather, it will encourage geese to stick around longer and potentially increase the risk of spreading the disease among the population that’s here,” Auel said. “It could potentially be a serious issue.”

Migration season is also stressful for geese, Ruden said. The long traveling distances, stocking up on food and weather changes are taxing on the birds.

“It’s a hard time to be a bird in general … being compromised, the immune system not performing and other factors,” she said. “And to be around so many of your species, it allows it to spiral.”

A big concern is the sickness transmitting to predatory and scavenging birds. Ladage said he’s seen birds of prey feasting on the dead birds as soon as they succumb.

“If watching geese perish was difficult, imagine the effect dead eagles will have,” he said.

Ruden said so far there is a low number of detection in mammals. That is usually found in younger animals who have not built up their immune system, such as fox kits and young possums.

With goose hunting season in full swing, hunters should be cautious with their kills. When breaking down a carcass, hunters should wear personal protective equipment and be in a well-ventilated area. Cooking meat to an internal temperature of 165 degrees will kill the virus, if present. Hunters should also prevent their hunting dogs from interacting with unknown carcasses and avoid feeding them raw meat.

The first human case of bird flu in Iowa was detected Dec. 20 in the northwest part of the state from an individual exposed to poultry in a commercial flock.

As for household precautions, Ruden said bird feeders for songbirds or backyard birds can remain up. She said the virus doesn’t circulate well and most won’t encounter the sickness.

“It’s not a foolproof situation but in a typical backyard not by water with retaining ducks and geese, those birds are unlikely to encounter the virus,” she said.

Auel said if a sick or dead bird is found, especially a raptor, a wildlife biologist should be called. He covers Black Hawk, Bremer, Buchanan and Chickasaw counties and can be contacted at (319) 213-2815.