Invasive snail blamed for hundreds of bird deaths on the Mississippi

An invasive snail is being blamed for the deaths of hundreds of waterfowl on the Mississippi River.

Close to 1,000 dead coot and lesser scaup have been found washed up on the shores near Genoa since October.

According to the U.S. Fish and Wildlife Service, the birds are believed to have an intestinal parasite found in faucet snails, which are a food source for waterfowl.

The parasite, called trematodes, can infect the birds and cause death within three to eight days, the La Crosse Tribune reported.

“They basically came in and basically out-competed native snails,” said Roger Haro, associate dean of University of Wisconsin-La Crosse’s College of Science and Health. “They’ve been around for a while but they never caused a detectable problem with waterfowl.”

Since the arrival of the snail, the bird deaths have been occurring annually for the past 15 years.

Faucet snails were first discovered in the early 2000s in Lake Onalaska, and are now growing on the river between La Crescent and McGregor, Iowa.

The National Wildlife Health Center said there are no reported health risks from handling or consuming the infected waterfowl, however hunters are still advised to wear gloves. Haro said the infected birds don’t appear to threaten other species.

“It’s kind of a jolting thing for people to see all these dead birds,” Haro said. He added that he and other university scientists continue to study the snails’ behavior and the effects of temperature variations on their growth.