Climate Change Means More Mice in Canada

Warmer temperatures and milder winters in Eastern Canada and the Northeastern and Great Lakes regions of the U.S. have been a boon to populations of the white-footed mouse.

In an interview with the Associated Press, Susan Hoffman, associate professor of biology at Miami University in Oxford, Ohio, said the rodents have migrated past a transitional forest region that has long served as a dividing line for many species. She said the white-footed mouse has expanded “surprisingly fast” in North America — about 125 miles in 30 years, which is 15 times farther than previously expected.

Hoffman is an expert in tracking the distribution shifts of small mammals, and the white-footed mouse in particular, due to environmental factors like climate change.

Historically, the white-footed mouse thrived in an area ranging from the Tennessee Valley to the northern Atlantic Coast. But already it has expanded its northern limit into Québec, said Hoffman. By 2050, she predicts the mouse population will migrate further north as the warming climate pushes its preferred forest habitats farther north.

Humans also are responsible for unintentionally moving the mice to new locations in cars, boats and recreational vehicles, she said.

More mice in and around homes and businesses will mean more work for pest management professionals. In addition to being a nuisance and causing food safety issues, the white-footed mouse is a natural reservoir for the bacteria that causes Lyme disease.