MSU researchers find Michigan's snowshoe hare population dropping off
Researchers have concluded that Michigan’s snowshoe hare population is declining at an alarming rate, and they are linking this problem partially to the effects of climate change.
Gary Roloff, associate professor in the Michigan State University Department of Fisheries and Wildlife, spearheaded the research as part of a study funded by the Michigan Department of Natural Resources to track the decline of snowshoe hares.
Researchers found that snowshoe hares have disappeared from nearly half of the sites studied in the Lower Peninsula of Michigan. In the Upper Peninsula, 27 percent of sites are now missing the snowshoe hare. In total, the research team studied 134 sites where snowshoe hares were historically found in Michigan.
“This decline is apparently occurring throughout Michigan but is particularly evident in the Lower Peninsula. Areas with historically abundant populations of snowshoe hares that supported hunting are now completely void of the animal,” said Roloff. "Snowshoe hares are an important ecological and cultural species in Michigan. Ecologically, hares are prey for animals such as bobcat, fisher, marten, coyote and raptors. Culturally, they are part of Michigan’s hunting heritage. When hunters have been asked why they stopped hunting hares, the consistent message has been there are too few hares in an area to make it worthwhile.”
Researchers link the decline to climate change, particularly warmer summers and winters without snow on the ground. Snowshoe hares change from brown to white as winter approaches, which offers them protection from predators. This change in coat color is triggered by photoperiod and not climate, so shorter winter seasons leave the hare without camouflage to hide it from predators.
Roloff said his team also found a link between warmer summers and hare population declines. Other researchers have suggested that warmer summers lead to decreased litter sizes.
One solution to the population decline may lie in subtle changes to forest management.
The study found that snowshoe hares prefer high-density stands with lots of vegetation cover, particularly conifers, for protection from predators. It also found that they will use cover created by blown-over trees or trees that are purposely knocked over. To improve habitat, foresters could leave or encourage a conifer component in harvested stands and, in areas without conifers, create cover by piling downed trees and tree tops.
State foresters said the new research will help in crafting forest management policies to deal with the effects of climate change on the snowshoe hare.
“The advice we have been able to provide was limited prior to this research, but if conditions line up right on given years, we could have an impact on the population,” said Dwayne Etter, wildlife research specialist at the DNR Rose Lake field office.
Researchers will continue to look into how other animals, such as the moose and ruffed grouse, may be affected by rising global temperatures.