Snowshoe hares are well adapted to survive Wisconsin, with their white fur helping them camouflage and hide from predators in the winter and vice versa with their brown coats in the summer.
But that same adaptation that gave them a leg up is now making them a target as the climate changes and there are fewer days with snow on the ground.
UW Madison Department of Forest and Wildlife Ecology Professor Jonathan Pauli explains their change in fur color isn’t driven by cold temperatures and snow, but by the length of daylight.
“What that means then is that these snowshoe hares are still turning white, but they're turning white before the snow actually falls, so they are now mismatched with their background, and they stick out in these forests like a bright, white light bulb, and are very vulnerable then to predation,” said Pauli.
Winter-Adapted Species
As result of this climate change, snowshoe hares are moving farther and farther north.
Pauli’s research has found that about every 10 years their populations contract to the north by about five miles.
“When we begin then to project into the future with increasingly shorter and shorter snow seasons, we're predicting that the snowshoe hare distribution in the state is going to become even smaller and really just held out at the most northern reaches of our state,” he said.
Part of Pauli’s work has been focused on how snowshoe hares can survive these changes.
He and his colleagues have found that habitat is key.
If snowshoe hares have 10-acre or so stands of early aspen and alder, then they appear to have just as high of survival rates as hares whose fur color matches their background.
“You could really erode the consequence of that mismatch, i.e., erode the consequence of climate change,” said Pauli.
There’s been similar findings when it comes to ruffed grouse, another species that’s been well-adapted to snowy winters with thicker feathers and the ability to roost in the snow.
“They are species that will kind of cycle, and they'll kind of go up and down in their population numbers, but what we started seeing, especially in parts of central and southern Wisconsin, is that they're not rebounding when they sort of show these population declines,” said Benjamin Zuckerberg. “We are actually beginning to see that these declines are becoming more and more chronic, and because of that, we're seeing some of these populations beginning to sort of blink off.”
Zuckerberg is a professor at UW Madison’s Department of Forest and Wildlife Ecology. He and Pauli have worked closely on winter-adapted species research.
Like the hare, Zuckerberg’s research has found that habitat can help in areas with a lack of snow.
Aspen stands and conifer cover can provide a similar buffer to the elements that burrowing under the snow does.
Zuckerberg says it then becomes a matter of working with land managers on growing the habitat to meet the needs, both now and into the future.
“This is a big part of what we do in terms of trying to incorporate what sort of future winters will look like. If we can incorporate some of those models and we say, ‘Okay, these are populations that might be more or less exposed to these changes in the future, what can we do in terms of being able to prioritize management in some of those areas?’” said Zuckerberg.
Zuckerberg and Pauli’s work involved collaborating with different agencies, organizations, and various landowners.
Midwest Climate Adaptation Science Center
It also fell under the Midwest Climate Adaptation Science Center, one of nine regional consortiums in the U.S. working to figure out how natural and cultural resources can adapt to climate change.
“It's a tremendous tool for pursuing adaptation science, because it organizes all these organizations and these people associated with them around a common theme, a common infrastructure, and provides a sort of mission and purpose to those people that orients them towards the development of adaptation solutions and putting them into practice with managers across the region,” said Jessica Hellmann, she’s the director of the Institute on the Environment at the University of Minnesota and serves as the director of the consortium that makes up the Midwest CASC.
The CASC is made up of six universities, the Great Lakes Indian Fish and Wildlife Commission, the Nature Conservancy, and falls under the USGS.
The research ranges from walleye fisheries to wild rice to the spread of invasive species.
In addition to projects done as a center, the CASC also awards grants to more research projects, and supports the professional development of new researchers.
“We have graduate students that we're training. We're building this future workforce,” said Hellmann.
The CASCs were created by Congress. The Midwest CASC broke off from the Northeast CASC in 2021 to focus more regionally on eight states including Minnesota, Wisconsin, and Michigan.
The core funding for all the CASCs falls under the USGS, specifically the Ecosystem Mission Area or EMA.
Hellmann explained that the other partners, like the Universities, are typically providing in-kind funds.
“They're contributing specific dollars. They're adding graduate fellowships. So the investment from the federal government is being matched by investment from other places,” she said.
Cuts to USGS
Science Magazine reported in April that the Trump Administration planned to ask Congress to erase the EMA from the USGS budget. The Trump Administration is also planning to lay off about 1,000 employees within the EMA, but that’s been put on pause as of May 23 by a federal judge.
“That's worrisome. We think a lot about we are partly the federal government, and those of us who don't work for the federal government, we really rely on our federal partners to get our science done and to get that science implemented,” said Hellmann.
The Fiscal Year 2026 budget priorities released by the White House earlier this month doesn’t specifically list the EMA, but it does call for $564 million in cuts to USGS “programs that provide grants to universities, duplicate other Federal research programs and focus on social agendas (e.g., climate change) to instead focus on achieving dominance in energy and critical minerals.”
Hellmann says it’s not her job to allocate money, but she knows the important value of the work they’re doing.
“We are pursuing science that doesn't exist. We haven't needed to adjust our management practices to a changing climate in the past, so we don't have a body of work to know what to be doing,” said Hellmann. “We need to be doing new science and then putting that science into practice. If that were to go away, that body of work in principle, would diminish or decline, and we would see it on the landscape in our natural and cultural resources over time.”
Both Pauli and Zuckerberg know the work the Midwest CASC does is important, with Zuckerberg saying losing it would have a crippling effect on science and the ability to translate science into action.
“I think that's a real disservice, obviously, that we are working hard, and in many cases, working with people on the ground, either agencies like the Wisconsin DNR or tribal partners, and in many cases, private landowners who are just looking to kind of gain more information about what they are seeing on their own properties and how to actually manage for it,” said Zuckerberg.
Congress will ultimately decide on the 2026 budget and whether the USGS funding is included.
