When otters attack

River otters
North American river otters are shown in a 2005 photo.
Photo by Dmitry Azovtsev, Creative Commons

Another Minnesota woman was attacked by an otter while swimming last weekend. It was the second attack in a month. An animal expert said the attacks could be due to pressures on otter habitats caused by development.

A St. Michael woman was attacked and bit 18 times last weekend while swimming in a lake near Aitkin. In mid-July, a woman was also bit more than two dozen times while swimming in a lake near Duluth.

George Parsons, director of fishes at Shedd Aquarium in Chicago, said otters are part of the weasel family. He said they'll sometimes use their very sharp canine teeth to defend their dens or young.

"The number of bites per victim is a little bit astounding to me," Parsons said on MPR's All Things Considered on Friday. "Usually they'll bite three or four times and then kind of give up."

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Parsons said otter habitats are being threatened by development, which just increases the chance that otters and people will come into contact.

Leah Prudhomme
Leah Prudhomme of Anoka, Minn., shown in an undated image, said she was attacked by an otter and bitten 25 times on Saturday, July 14, 2012, while swimming in Island Lake, 17 miles north of Duluth.
Courtesy of Leah Prudhomme

But given a choice, otters will generally avoid interacting with humans. Parsons recommends swimmers avoid areas where they build dens, marshlands or places with fallen trees.

"Be as loud and boisterous as possible and usually that will chase otters away," Parsons said. "Especially if you see otters with pups and young, just try to stay clear of that, even on land."

Parsons said otters could also be more active this year due to the heat.