BEAVER — Michael Joyce stood atop a cold Whitewater Valley bluff, ready to take a deeper look into the life of a fisher, a small, reclusive carnivore making a dramatic comeback to the southeast after being wiped out a century ago.
The wildlife ecologist with the Natural Resources Research Institute, part of the University of Minnesota Duluth, is leading the first research about fishers because he’s fascinated by that large member of the weasel family that was once thought to live only in old-growth conifer forests, such as those in northeastern Minnesota. The thought was wrong. They are taking to the southeast and its deciduous forests in large and growing numbers.
Besides fishers, bobcats are also returning, though where they are coming from and their ecological needs differ. The two don’t always get along and bobcats will kill fishers, not for food itself but to give them access to more of their prey, such as rabbits, squirrels, mice, grouse and turkeys, he said. Down here, thus far, no wildlife experts have seen any killings.
A Department of Natural Resources map of verified or reported sightings of the two carnivores shows fishers have a stronger preference for the rugged, wooded blufflands, especially near the Mississippi River. They are coming from up north where they once thrived but their population is declining.
Bobcats are more spread out and like a more diverse habitat that includes more open fields and field edges. They are coming both from up north as well as from southern states, Joyce said. The first confirmed sighting in the southeast was in 2005; since then, “there has been a huge increase.”
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Some of the dots on the maps could be from the same animal, but there are also fishers and bobcats that aren’t recorded, said John Erb, DNR furbearer/wolf research scientist. He began recording them around 2005 but a fairly high number were reported in the past seven years, he said. “There seems to be a ramping up of the increase,” he said.
While they differ, they are here in large enough numbers that the DNR might consider a limited trapping season in a few years, he said.
Joyce is asking anyone who sees a fisher or bobcat to let him know; pictures or other evidence is especially good.
Email him at wildlifeNRRI@d.umn.edu (using subject line "Fisher sighting”). You can also fill out a Google Form that lets you attach photos or videos; go to https://z.umn.edu/fisher-sightings .
The biggest part of understanding fishers, though, is his project that will help find where they live, how many are here, how big their home territories are, what they eat, how many young they have.
Which is why Joyce, and his technician, Kesley Secrist, stood atop that bluff and looked down a long, steep Whitewater bluff side, packed with crusted refrozen snow and open areas with last year’s leaves frozen into a near ice rink.
The radio collar on the female told Secrist it was in a den with kits; they knew the den was high in an old aspen tree near the bottom. They had hoped she was out hunting so they could use a pole to slip a camera into the den to count the kits.
The two still decided to go down to check trail cams and scats that tell what the fisher has been eating.
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At first, descending wasn’t so bad. They zigzagged through nasty prickly ash but they could dig their boots into the crusted snow for grip. Once they got to a steeper area with less snow, it was treacherous and they had to grab trees or almost sit down as the walked/slid down.
Finally, they got to the tree. The nest cavity was about 20 feet up and quite small. They checked the three cameras and found pictures of the female as well as raccoon and squirrels. Scats at the base of the tree told Joyce the fisher had killed a rabbit. When done, Secrist went back up the bluff side to get her all-terrain vehicle. Joyce wisely went all the way down to reach a much easier trail to walk back up.
“They certainly don’t make it easy on us,” he said.
The problem isn’t only do they nest in remote areas, but also that they aren’t consistent in when they move to feed, some times going out around midnight, sometimes in mid-afternoon. He and Secrist have to guess when the adults will be moving so they can peek into the nesting cavity. The male is making it even harder because he moves around much more than the females, going in a 12-mile swath from the Whitewater valley and south.
Furthermore, the females move to new nests several times throughout the year so researchers have to find the family again and again. In fact, the two had to find a new nest several days later and this time the female was gone so they were able to count kits - four, the highest known for fishers.
While they don’t make it easy, they do make it interesting. He is captivated by being able to see and learn more about the elusive fishers. The study will go a few more years, so more learning is yet to come. Optimistically, Joyce said he has 10 percent of what he needs; realistically, it’s 5 percent.
The female is one of five live trapped and radio-collared in the region, he said. One female slipped its collar and another died for reasons as yet unknown, he said. He has collared eight more up north.
The plan is to eventually get 28 collared in the south.
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Here are some of the important things known about fishers in Minnesota and some of the key questions:
- They once lived in much of Minnesota but were extirpated by 1929. “They have taken a while to come back but they don’t have a lot of young per year.” Up north, they average two to three kits per year; down here, it’s believed they will have more because of better conditions. If that is so, fisher numbers would be larger per square mile than up north.
- They peaked in northern Minnesota about 20 years ago and are now declining. Their population was once up to 3,300 but now, it could be closer to 500. “It really is a weird situation,” Joyce said. “It’s not what I would have expected.”
- For trappers, fishers are more of a “trophy furbearer” because they are so elusive and rare. Trapping numbers have also fallen, in part because of lower numbers and with that, has come less effort.
- They are “solitary, territorial carnivores” eating snowshoe hares, red squirrel, grouse and rodents. Females weigh 4 to 6 pounds, males up to 15 pounds. They don’t overshoot their carrying capacity because they have their territories. Up north, female territories are about 6 square miles but males need 14 square miles. They have “intersexual territoriality” in which males don’t overlap other males’ territories and females don’t overlap on other females but males will overlap with females and females with males. He’s trying to find out what the territories of the fishers are down here. So far, he’s seeing females have a smaller home range than up north. Does that indicate food and habitat are better? “It would seem to indicate that, yes,” he said.
Erb said the present trapping season is basically only north of Interstate 94 but that could change in a few years. It won’t be next year but “it has been discussed and will continue to be discussed,” he said. “Biologically we are getting to the point where we could have a limited season.” And that also goes for bobcats.
This project was funded by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources.
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