by Gustave Axelson
Ron Moen slowed his pickup truck and peered through a veil of balsam fir trees. He saw something dark in the box trap he had set in the backwoods of Isabella, deep in the Superior National Forest.
"We've got something," he whispered. Then he instructed me to gingerly shut the truck door ("Don't slam it.") and not speak a word. We crept through the balsams, and there, crouched at the back of the trap, was another day's work for Moen—a creature most people go a lifetime without seeing.
Video clip: Ron Moen releases a lynx from a box trap. This video requires the latest version of Adobe Flash Player
Video clip: Ron Moen releases a lynx from a box trap.
The lynx was silent and still, save for swiveling its wide, whiskered face to watch our every move. I sat down to admire a wild lynx in temporary captivity, to regard the black tassels on its ears and the inconceivably oversized furry paws and the smoky fur, that classic boreal gray color that I've seen before on woodland caribou up in Canada. But unlike caribou, lynx are still here in Minnesota.
The confirmed presence of resident lynx was a key finding by Moen and his research team of students and interns from the Natural Resources Research Institute at the University of Minnesota Duluth. In March 2003, they began placing radio collars and GPS collars on Canada lynx (Lynx Canadensis) in northeastern Minnesota. Over the past eight years, 34 lynx have been collared and tracked. In analyzing the data, Moen has answered fundamental questions about lynx habits and habitat in Minnesota.
Judging from trappers' records, Minnesota historically had a relatively abundant lynx population. From 1929 to 1969, Minnesota trappers reported an average annual harvest of 177 lynx, the highest recorded harvest among the lower 48 states. Harvests spiked every 10 years when the snowshoe hare population in Canada crashed and hungry lynx flooded into Minnesota. One such year was 1962, when trappers took 387 lynx. But the 10-year bubble in Minnesota's lynx population never materialized in the early 1980s. In 1984 the Department of Natural Resources closed the lynx harvest, and it remains closed today. Throughout the 1980s and into the '90s, lynx were rarely spotted. Some biologists doubted whether Minnesota could support a resident lynx population.
Nevertheless, the U.S. Fish and Wildlife Service included Minnesota when it listed the lynx as "threatened" under the federal Endangered Species Act in 2000. The federal listing resulted from lawsuits by environmental groups. Additional lawsuits in Minnesota challenged timber harvests and new roads and trails in the Superior National Forest on the grounds that such actions would disturb lynx habitat.
In the early 2000s, people in the Arrowhead region started seeing lynx again. And suddenly, the USFWS and DNR had a new threatened species to manage in Minnesota. But reliable research to guide management decisions was scarce. Most of what was known about lynx was based on research conducted in the Rocky Mountains. Little had been done to study lynx in the midcontinental region—until Moen and his NRRI team began work.
Lynx #1 in the NRRI project was lured into a box trap by a chunk of road-killed deer on March 14, 2003, near Isabella. A 17-pound yearling male, he was sedated, outfitted with a radio collar, and released. He promptly traveled 55 miles north into Canada, where he was legally caught by a commercial trapper in November.
With funding from a variety of sources (including the DNR, USFWS, U.S. Forest Service, Potlatch Corp., Minnesota Trappers Association, and Defenders of Wildlife), the research team collared 32 lynx from 2003 to 2006, and two more in 2009. Most were outfitted with VHF radio collars and periodically tracked by car or airplane with a researcher holding an antenna and listening for beeps on a radio receiver. GPS collars on 10 lynx kept an ongoing log of locations. To investigate reproduction, Moen's team searched for females in May and June when they might be on den sites.
The data collected on radio-collared lynx has provided peeks into the lives being led by lynx in Minnesota, and it revealed a fascinating insight: They often visit Canada. After being captured near Grand Marais in January 2004, Lynx #9 traveled northeast about 200 miles, well into Ontario and north of Lake Superior, only to turn around and come back to Grand Marais before year's end.
Lynx #11 holds the study's record for farthest travels. She was located near Manitouwadge in north-central Ontario, more than 400 miles from where she was first captured near Isabella. Two other lynx also traveled to Manitouwadge. In seven years of tracking data, about 40 percent of lynx made long-distance trips, frequently into Ontario.
Though they liked to wander, Moen says many lynx were definitely making their homes in Minnesota. More than 75 percent of radio-collared lynx captured in Minnesota remained in the state at least a year, and lynx were present in every year of Moen's study. Moen says their residency can be interpreted in two ways: "You could call it a small resident population that's fed by 10-year influxes from Canada. Or you could call it an international population that has no regard for the U.S.–Canadian border, roaming back and forth."
DNR furbearer biologist John Erb agrees with Moen's conclusion. "We may have always had some level of lynx in Minnesota. There was clearly a significant downturn in the 1980s and '90s, though people may not have been looking for them as much then, in part because the trapping season was closed," Erb says. "Northern Minnesota is a large place, and it's likely that a few lynx were at least temporarily residing and reproducing in Minnesota every year, whether we documented it or not.
"The only reason to talk about whether lynx are Minnesotan or Canadian is for legal reasons. A few hops by a lynx may convert it from a federally protected U.S. animal to a Canadian animal [that can be legally trapped]. But there's clearly a southern boundary to the larger Canadian lynx population that … currently includes portions of northern Minnesota."
Almost all of the lynx scat recovered during the project contained snowshoe hare remains. Accordingly, lynx habitat requirements boil down to a simple equation: Lynx need snowshoe hares, their primary prey.
Lynx tracked with GPS collars established their territories in young conifer forests with abundant hare populations. Moen concluded that logging in Minnesota can actually create lynx habitat, if that logging creates hare habitat—particularly 10- to 40-year-old stands of firs, spruces, cedars, and pines. Such conifers provide food and cover for hares, whose populations can rapidly boom if conditions are right. Moen says the Isabella area has excellent lynx (and hare) habitat because of logging disturbance and abundant conifer forests. He says the Gunflint Trail is another area that could become prime lynx habitat over the next 10 to 15 years if young conifer stands regenerate from the blowdown and fires.
In tracking lynx movements, Moen also found that they made frequent use of roads and trails, probably because they offer easier traveling than walking through the woods. When the research team looked at travels by lynx with GPS collars outside of the BWCAW, about 20 percent of the locations were directly on roads or trails and 75 percent were within 200 meters of a road or trail. Moen says that such data shows that lynx can be somewhat adaptable in their habitat needs.
"One lynx den was 100 feet off [a highway], near railroad tracks and an active gravel pit. They're not the shy wilderness creatures they were thought to be a while ago," he says, though he adds that lynx can just as well live entirely in a remote wilderness area, so long as hares are there.
Every adult female lynx in the study had a litter in every breeding season during which they were radio-collared, with 33 documented kittens in all. Lynx #7 became the first female in the study to den and have kittens in June 2004. Lynx #17, a kitten from that 2004 litter, had her own kittens in 2006—marking the first recorded instance of successful breeding by a Minnesota-born lynx.
But Lynx #17 was the only confirmed Minnesota-born breeder. Moen says that thus far the project has not documented widespread recruitment (a resident population adding new individuals via reproduction). However, such a finding is technically difficult to measure for an uncommon and secretive species. For the NRRI project to assess recruitment, a large sample of kittens must be monitored for two years from birth in the den through dispersal and a breeding season as an adult.
Other biologists in northern Minnesota say they have seen enough evidence of lynx kittens to be convinced of a successful breeding population. USFS wildlife biologist Dan Ryan says he has seen evidence of lynx kittens being born every year in the Superior National Forest for the past nine years. Independent wildlife researcher Steve Loch, who has also studied lynx in the area, has seen lynx kittens in 10 consecutive years. "I've tracked females that spit out litters four years in a row," he says.
Moen's study also confirmed something that has been documented elsewhere: Lynx have high mortality. In Canada, lynx mortality rates have averaged 55 percent, reaching as high as 90 percent in the Yukon. Of the 34 radio-collared lynx in the NRRI project, 17 died from various causes, including car kills, a train kill, legal harvest in Canada, and some incidental trapping and shootings in Minnesota. Moen lost track of another 15 lynx, either because their radio collars stopped working or because they wandered too far from the study area. Two lynx are still being monitored, including Lynx #28—a male that was first captured and collared six years ago.
The most troubling trend for lynx in Minnesota, says Moen, isn't biological, but social. Past lawsuits over logging and trails, as well as the regulations that go with a federally listed threatened species, have cast lynx into a wildlife-versus-land-use debate. Moen says his research shows lynx do not need to be a flashpoint for controversy.
"The lynx issue doesn't have to be a repeat of the wolf delisting debate," Moen says. Instead, Moen recommends convening a lynx advisory council—consisting of government agencies, environmentalists, hunters, trappers, and timber interests—to develop a long-term, unified plan for lynx in Minnesota. Ideally, Moen says lynx could be promoted as charismatic megafauna, a species that "along with wolves and moose enhance the tourism industry in northeastern Minnesota."
The lynx I watched in Moen's box trap didn't exhibit charisma so much as mystique—not a hint of panic or anger about its predicament, just quiet confidence and an intense stare as it eyed Moen's hand lifting the trap door. The lynx burst straight toward me, then changed course without breaking stride and ducked behind a row of balsams. Just 10 yards away, the lynx slowed to a saunter and vanished silently, with nary an echo of crunching snow or snapping twigs.