In a forest clearing outside Ely, Minn., two scientists huddle over a moose calf as it dozes in the snow.
The female calf is only nine months old but already weighs almost 500 pounds. It’s been sedated by a tranquilizer dart just long enough for biologist Morgan Swingen and veterinarian Mary Wood to do a physical exam and slip a tracking collar around its neck.
Soon, the calf rises and bounds through the snow to catch up with her mother.
She will wear that collar for up to three years, said Swingen, a wildlife biologist with an inter-tribal natural resource agency called the 1854 Treaty Authority.
“The collar collects GPS locations of where the moose is, so we can see what types of habitat the moose are using. If the collar stops moving, it will send a notification, and that often indicates that the animal has died,” Swingen said. “We don’t have data really from our state on survival of this younger age class of moose.”
The number of moose in Minnesota is about half what it was just 20 years ago. Conservationists have had some success stabilizing the population, but moose are under increasing pressure from parasites, predators and the warming climate.
After collaring the female calf, Swingen and Wood ride a helicopter back to camp, which is an ice fishing trailer tricked out into a mobile laboratory.
It’s the base of operations for state scientists and two local tribes trying to determine what’s holding back the population of moose in Minnesota. They’re putting tracking collars on as many moose as they can find with the help of a spotter plane scanning the wilderness with an infrared camera.
Scientist Seth Moore follows the plane in a helicopter and hops out when they find a moose.
“Today I think we’re at about five or six degrees Fahrenheit. We’re flying in a helicopter with no doors, absolutely none,” Moore said, “so you have a wind chill that is absolutely brutally cold.”
Field work in February in northern Minnesota has its challenges, said Moore, director of biology and environment for the Grand Portage Band of Lake Superior Chippewa. Blood samples freeze. High winds ground the helicopter for days. But he said the data is worth it.
“In our past work, we’ve looked at how calves might survive their first year based on predation rates, and we’ve worked on what is causing adult mortality,” Moore said. “But we’ve never really looked at this life stage of the juveniles that have made it through their first growing season but haven’t yet begun to reproduce.”
Juvenile moose might be the key to growing the population, said Michelle Carstensen, wildlife health group leader with the Minnesota Department of Natural Resources.
“They’re the next generation. Think of them now as teenagers. We’re trying to get them to graduate and get a job and be productive in society because they’re the future of what this population can be. So, for these animals that we’re encountering now, are they going to make it through the winter?” Carstensen said. “Think of it as like wildlife CSI. And then if you figure out some of the drivers, what can we do about it?”
A centrifuge in the ice-hut lab spins vials of moose blood as the helicopter team heads out with more collars.
Moose sanctuary
For the last 15 years, a group called The Minnesota Moose Habitat Collaborative has been putting some of that science into action at places like Sand Lake/Seven Beavers, an 18,000-acre preserve of conifer forest and wetlands abutting Minnesota’s Finland State Forest.
It’s a living experiment in rebuilding moose habitat, said Chris Dunham, associate director of resilience forestry at the Nature Conservancy.
There is evidence it’s working: From his snowmobile, Dunham spots a clump of moose hair and hoofprints in the snow. Further down the trail, he finds a rub where a bull moose has scraped off the bark with its antlers.
In 2021, a wildfire thinned out parts of this mature forest and made room for younger, shorter trees that are easier for moose to browse. Adult moose can eat more than 70 pounds a day of vegetation and woody plants during the summer; It’s little wonder the word moose comes from the Ojibwe for “twig-eater.”
“You can see all this vegetation that looks like thin sticks poking up. A lot of that is Aspen. That’s young, and it’s vigorous, and it’s moose food. So that’s just perfect,” Dunham said. “This is why we think this area is really just going to turn on as a great moose habitat.”
Moose need more than just woody plants to munch. They also need the shade of taller trees in the warmer months, as well as wetlands, so Dunham said managing the land for moose habitat is good for the overall biodiversity of the forest.
In winter, the forest is still and silent except for a woodpecker hammering its beak on a pine. A northern hawk-owl roosts on the crown of a leafless tree to hunt.
Another reason this preserve is prime moose habitat, according to Dunham, is its relative lack of deer. White-tailed deer carry two parasites — liver fluke and brainworm — that can be fatal to moose. More deer also means more wolves, which prey on baby moose.
Dunham said a stretch of hard winters helped clear out the deer, at least temporarily.
“It’s great to have a place like this where we want to feature moose and help moose, and we don’t have a lot of deer. We kind of hope it stays that way,” Dunham said. “I love deer for like two weeks in November: hunting season.”
Stressful summers
Back inside the ice-fishing trailer turned field lab, Carstensen keeps track of how many moose the team has collared: 54 so far.
This is the beginning of a multi-year study, so the full results will take time. But climate change is making their research more urgent.
Mild winters mean more parasites, especially winter ticks, which can infest moose by the tens of thousands.
“Even though ticks have been around and the cycle continues, we used to have more severe winters more often, and so it would break that cycle a lot more,” Carstensen said. “We have a species that’s living kind of at the southern edge of where moose exist in North America. They are the most vulnerable to even slight changes in the system.”
Hotter summers are also a problem for moose. Carstensen has studied the animals’ body temperature and found moose were less likely to die following a hot summer if they had access to healthy forests with a mix of short, woody moose food and tall trees for shade.
“The ones that died at a higher rate were more active during the day to try to find food when moose that were surviving were bedded down and chilling,” Carstensen said. “It’s likely the ones that were more active needed to find food, and they were forced to continue feeding and moving and foraging when they should have been having a margarita and sitting in the shade.”
The good news, said Dunham of The Nature Conservancy, is that land managers know what kind of habitat gives moose the best chance at thriving in a warmer world.
“Climate change is big and scary, but there are things that we can do,” he said, “and we’re getting after it.”
Still, climate change may move faster than conservationists can protect moose habitat. It could push the population to the north, potentially out of Minnesota and off tribal territory.
Moore, who works for the Grand Portage Band of Lake Superior Chippewa, said that would be “devastating.”
“I’ve spent 20 years trying to restore moose populations in Minnesota. And I feel like we’re starting to see some progress,” he said. “To me, it looks promising, but I do think we need to pay attention and keep our fingers on the pulse of these populations so that we can continue to manage to restore them.”
He wants future generations of Minnesotans to share the Northwoods with moose.
“One of the principal philosophies in an Ojibwe worldview is what is called Seventh Generation planning. And it’s this idea that we leave this Earth in a manner someone seven generations from now can use it the same way that we do presently,” Moore said. “We have this burden of responsibility to leave the Earth so that our great-grandchildren can use it as we do now.”
This article was originally published on WBUR.org.
Copyright 2026 WBUR