Minnesota's Canada Lynx
The saga began in 2000 and continues through 2006
The Missing Lynx
The scarcity of lynx in northern-tier states has landed the critter on the federal list of threatened species. Will that help the lynx to "recover?"
By Greg Breining Dec. 2000
Last fall, wildlife researchers laid out a 200-square-mile plot north of Isabella, just south of the Boundary Waters Canoe Area Wilderness in northern Minnesota. Accessible by trails and forest roads, it contained large areas of the spruce, fir, and cedar thought to be preferred by Canada lynx and their primary prey, snowshoe hares.
At 125 locations within the plot, technicians set up "hair snares" -- a pie tin dangling from fishing line as an attractor, a pad baited with beaver castoreum and catnip oil, and a Velcrolike patch nailed to a nearby tree. A lynx, like a rangy house cat, would spot the pan, sniff the scents, and rub against the patched tree, leaving its own scent -- and a sample of hair.
Driving and bushwhacking to each station twice in a month, technicians collected hair, storing each specimen in a vial. Hairs that appeared to belong to a cat were sent to the U.S. Forest Service Rocky Mountain Research Station lab in Missoula, Mont., for DNA analysis to determine if they came from a lynx. The system had worked reliably in the West to determine if lynx were around.
During the fall and winter the researchers conducted this same experiment in Chippewa National Forest, northwest of Grand Rapids, and national forests in northern Wisconsin and Michigan's Upper Peninsula. In all, they set up 750 hair snares on 1,200 square miles of likely lynx habitat and sent 28 hair samples for DNA analysis.
Not one hair belonged to a lynx.
"I wasn't surprised," said Gerald Niemi, director of the Center for Water and the Environment at the Natural Resources Research Institute, University of Minnesota-Duluth, and head of the sampling project. "If you're looking for a needle in a haystack, you need a broad sample."
Elusive Lynx
If any Great Lakes wildlife species is a needle in a haystack, it is the elusive and far-ranging lynx. Its numbers in Minnesota have been as high as the hundreds and perhaps as low as zero. Partly because of its periodic rarity, the U.S. Fish and Wildlife Service listed it last spring as a federal threatened species.
But the designation has been controversial. The Minnesota Department of Natural Resources opposed listing because some biologists aren't sure resident populations of lynx were ever present in historical times and doubt if they can be established in the future. If that's so, disruption to logging practices and snowmobile trail locations that such listing could produce would be futile.
"You're constraining other activities and wasting resources on things that aren't going to work," said Mike DonCarlos, DNR furbearer specialist. "There are all kinds of problems we should be devoting our attention to. This is not one of them."
Attracting Lynx
Will setting aside habitat attract more lynx? Asked one federal forest planner: "If we build it, will they come?"
Scientists don't know, just as they don't know very much at all about lynx in Minnesota. (Much of what they do know and most of the background in this article is contained in The Scientific Basis for Lynx Conservation in the Contiguous United States. Published in 1999 by the USFS Rocky Mountain Research Station, it is called simply the "science report.")
The lynx, twice the weight of an average house cat, lives in the coniferous forests of North America, primarily Canada; hence its scientific name, Lynx canadensis. Long legs and huge feet enable it to run in deep, powdery snow in pursuit of snowshoe hares. So dependent is the lynx on the hare that the 10-year boom-and-bust cycles common to the hare, especially in the far north, are mirrored in the lynx population. A year or two after hare numbers drop, lynx also decline -- often to just 5 to 10 percent of the original population as lynx starve and fail to reproduce.
As hare numbers dwindle, lynx roam in search of food, moving several miles a day for straight-line distances of more than 100 miles. They migrate south into the conifer-hardwood forests of Minnesota, Wisconsin, Michigan, and Maine, where there had been few or no lynx. Peaks in these southern populations follow peaks in central Canada by two to three years. After a couple of years, populations in southern areas such as Minnesota drop from hundreds, or thousands, to nearly zero.
What prevents the lynx from pushing its permanent range southward? Scientists don't know. But several factors may be at work:
Low densities of snowshoe hare in the southern portion of lynx range compared with the north. While the hare lives in northern and eastern Minnesota, numbers are typical of what would be found in Canada during its low phase. Though lynx eat red squirrels, grouse, and other foods, they apparently don't flourish and reproduce without an abundance of hares.
Lack of suitable snow. Lynx, like hares, are built for deep powder. In areas with less snow, or firmer snow, lynx may lose out in competition with bobcats and coyotes. Both are more aggressive than lynx. Both are more adaptable predators, eating not only hares, but also a variety of other prey; so they survive as lynx starve. That's the hypothesis, but there's little hard science to describe the competition between these three predators. Research in Minnesota has not revealed competition between lynx and coyotes.
Development in potential lynx habitat that may increase competition between species to the detriment of lynx. Coyotes tend to be more numerous where farms are common. Some biologists suspect that roads and trails may give coyotes and bobcats a way to hunt and scent-mark where otherwise the snow would be too deep for all but the lynx. Does development actually affect lynx numbers? It's an interesting hypothesis for which there is little published evidence.
Trapping in Canada, which may have helped decimate lynx after their most recent boom in the Great Lakes region in the early 1970s. Since then, Ontario and Manitoba have further restricted trapping. Minnesota banned hunting and trapping of lynx in 1984. Despite the restriction, the lynx population has not rebounded.
Logging in a way that reduces hare habitat and clears the downed trees that lynx use as denning sites. Clear-cutting, rather than selective cutting, leaves even-aged stands, which may provide less-than-ideal hare habitat over the long term. While young stands hold plenty of hares, middle-aged stands do not. Old stands, with an emerging understory of young trees and brush, also hold hares. Biologists speculate that the best forest for lynx includes stands of many ages, from patches of young aspen and conifers to groves of old trees with deadfalls.
Mistaken Identity
As far back as 1892, in "The Mammals of Minnesota," author C.L. Herrick wondered if lynx lived in the state. All the purported specimens he examined proved instead to be bobcats. But apparently a few lynx were around, as evidenced by eight museum specimens dating from 1892 to 1900. Verified reports of lynx remained scarce during the early 1900s, though at least two wandered as far south as Sherburne and Morrison counties.
Harvest records published by the DNR tell of more lynx -- an average of more than 100 lynx trapped per year, with peaks of several hundred in 1930, 1940, 1952, 1962, and 1973. However, the data were based on mail surveys and should be viewed with some skepticism, with regard to both species and number of animals reported. At the same time, trappers caught very few lynx -- in some years none at all -- during the lynx's cyclic lows.
Did the recent hair-snare survey prove no lynx live in Minnesota? No, said Niemi. It really indicated there were no lynx in the study areas at the time of the survey. Niemi said he would like to repeat the survey over broader areas, especially in the difficult-to-access Boundary Waters, perhaps the region in the Great Lakes states most likely to sustain a population of lynx.
Do lynx form a viable resident population? Niemi said, "We don't really know for sure."
Others are more dubious. U.S. Geological Survey researcher L. David Mech, who studied lynx during their most recent incursion into Minnesota in the early 1970s, said, "We just get the tip of the overflowing population from Canada."
During the lynx's cyclic lows, said Bill Berg, wildlife biologist for the DNR, "You can count the number we have on one hand. Essentially there's not an animal in the state."
Thrusts and Parries
Despite the sporadic numbers of lynx in northern-tier states -- or because of them -- environmental groups petitioned the USFWS in 1991 to list the lynx as an endangered species. A series of thrusts and parries, most centered on the Pacific Northwest and Rockies, ensued between environmentalists and federal officials. Environmentalists sued for a third time, the parties negotiated, and this time the USFWS agreed to list the lynx as threatened. The listing took effect last March.
Defenders of Wildlife, one of the groups involved, argues that protection of lynx habitat in areas such as northern Minnesota is important to "maintaining connectivity with habitat in Canada, so that they have the opportunity to continue to travel back and forth from Canada to Minnesota," according to Mike Leahy, a lawyer for the group. In particular, Leahy said, environmental groups are concerned about timber-cutting practices and the location of new roads and trails. "The lynx is an incredibly beautiful animal. It is as much a part of the north woods as the loon, the walleye, or the moose."
Berg sees the listing in different terms. By his reckoning, environmental groups were looking for a lever by which to force the federal government to restrict road building and timber harvest. "They needed a four-legged spotted owl, and the lynx is it," he said. "It's a pretty sad use of the Endangered Species Act.
"The work that was responsible for listing the lynx as threatened was dominated by research in the Rockies and western Canada," Berg said. "States like Minnesota and Maine were ignored. In extreme northern Maine, several radioed lynx there are found only in forests that were extensively logged five to 20 years ago.
"If you were to take all of northern Minnesota . . . and manage it for nothing but lynx -- forget all this management for old growth or young growth or whatever, manage everything for snowshoe hares and lynx -- you still wouldn't have any," Berg said. "You wouldn't have any until a few animals come down from Canada."
In the meantime, designation has the potential to disrupt logging, wildlife management, and recreation. Of the listing, Berg said, "It's loaded with a lot of politics and darned little biology."
Will They Come?
Berg's argument strikes at two fundamental issues that trouble opponents of listing the lynx.
First , scientists have no good evidence that they can manipulate habitat in a way to encourage more lynx to migrate into Minnesota or to enable them to survive once the hare population declines. Bald eagles were restored by banning DDT and protecting nest sites. Gray wolves recovered once people stopped poisoning and trapping them. What we might do to sustain lynx is less clear: If we build it, will they come?
Berg argues that the warming of Minnesota's climate since the late 1800s may make it all the more difficult to sustain lynx. During the past several decades animals such as opossums, skunks, white-tailed deer, and raccoons have extended ranges northward into Canada, while species such as wolverine and woodland caribou have retreated farther north. "No bird or mammal species in Minnesota is expanding its range southward," Berg said. "Everything is moving north." (An exception is the wolf, which is still recovering from past hunting and trapping.) Changes in land use play a role. But if climate is the driving force, what is the chance of restoring a boreal creature such as lynx?
Second, if the lynx's presence in northern Minnesota is merely a spillover of famished refugees, as Berg believes, the conventional biological justifications for protecting populations are less than persuasive:
To save a species. The lynx's primary home is Canada's boreal forest. What happens in Minnesota will not affect the vast majority of lynx.
To conserve a subspecies or unique genotype. Evolution occurs in isolated populations, whose unique genetics provide the characteristics a species requires to survive a changing environment. But the federal science report cites no evidence that the lynx found in Minnesota differ genetically from lynx of Canada, or that they are discrete in any way. Indeed, all or nearly all come from Canada. Nonetheless, the report cautions, "until we understand the nature of geographic variation in lynx populations, it would seem prudent to assume the existence of important genetic and nongenetic differences among populations, especially those that are distant and/or relatively isolated."
To provide interbreeding and migration in and out to sustain an outlying population. Small, isolated populations are vulnerable to extinction through disease, famine, inbreeding, and other catastrophes. But what is the value of "connectivity" to a population that naturally advances and withdraws like waves on a beach?
To stabilize an ecosystem by maintaining a species that fills a unique ecological niche -- in this case a midsize predator built for deep snow. How vital to an ecosystem is one predator among many if it shows up only periodically and then disappears?
Not Wrong
"Anyone who feels the lynx should not have been listed based on the biology is clearly not wrong," said Paul Burke, biologist for the USFWS. "Anyone who feels the lynx should have been listed is not wrong. Let's learn what we have to do to keep the lynx part of our ecosystem."
Niemi will continue his surveys this fall and winter. Over time such surveys can help determine if lynx of Minnesota, Wisconsin, and Michigan do form a resident population.
Defenders of Wildlife and other groups are suing the USFWS again, this time for failing to treat lynx populations in the northern states as discrete; for listing the lynx as threatened rather than the more imperative endangered; and for failing to designate critical habitat.
In the Great Lakes states, the USFWS will assemble a team of researchers and resource management specialists to develop a lynx "recovery plan" within four years.
"Climatic change needs to be carefully considered," Burke said. If the evidence makes it clear that the lynx no longer can survive in the United States "due to conditions beyond our control, there is indeed a method for the lynx to come off the list."
If, on the other hand, the team finds that habitat changes might increase the number of lynx in the region, there might follow changes to forest management and trail and road development. In the meantime, national forests might make some changes to their forest management plans based on what scientists suspect is true of the lynx.
Researchers must learn more about habitat needs. "That is not easily done with lynx," Burke said. "The men and women who trap spotted cats in Minnesota can tell us more about where to set a trap to get one than all the available literature."
The science report, which acknowledges that "we know very little about lynx ecology in the United States," adds that "it is inappropriate to expect scientists to solve complex problems in a single stroke. Yet this is often what ecologists are called upon to do when land managers and decision makers find that they lack sufficient understanding to meet legal mandates for environmental protections."
Burke agrees: "We've got an awful lot to learn before we start jumping to conclusions."
Greg Breining is the Managing Editor of the Volunteer and author of Wild Shore.
Minnesota: No doubt, the lynx is back
Researchers are finding many of the wild cats, which were thought nearly extinct in Minnesota.
Source: Copyright 2005, Duluth News Tribune
Date: June 6, 2005
Byline: JOHN MYERS
NEAR BRIMSON - In a tangled patch of blown-down spruce and balsam on the south edge of the Superior National Forest, Lynx No. 13 growled an angry warning.
Momma lynx was clearly not a happy cat as she watched -- just 20 feet away -- researchers poke, prod, tag and weigh her four kittens.
She never came closer, but No. 13 also never left, eventually sitting and softly growling while the scientists did their work with the 3-week-old kittens.
``We try to keep our time in here to a minimum, keep the intrusion as little as possible. . . . But they really don't seem to have any long-term reaction to us,'' said Ron Moen, lead researcher for the lynx project for the Natural Resources Research Institute of the University of Minnesota Duluth.
Less than 20 minutes later, the spotted-gray kittens were placed back under the fallen tree their mother had picked for their den, and the researchers and visitors quietly walked away from some of the newest members
of a growing population of Minnesota lynx.
LYNX GALORE
Just five years ago some biologists in Minnesota declared lynx all but eliminated from the state, saying the few sightings were probably lynx wandering through from Canada.
But when researchers started looking hard, they found lynx across St. Louis, Lake and Cook counties. Last year, a lynx den was discovered in Minnesota for the first time in more than 20 years.
Now, more than 60 individual Minnesota lynx have been confirmed through DNA testing. More lynx DNA samples await laboratory confirmation. And at least four female lynx this month are raising several more kittens to add to the mix.
All those have been in just three northeastern counties, before researchers were able to get money to expand their search westward across the state -- work that will start later this year.
``They've been found as far west as Red Lake for sure, and one was hit by a vehicle near Hinckley. Their range is fairly broad now,'' said Ed Lindquist, biologist for the Superior National Forest.
Moen said the skeptics may have been right -- that there may have been no lynx, or just a few, in the 1990s. But times have changed.
``The numbers are definitely going up,'' Moen said.
PERMANENT RECOVERY?
Lynx were once common in Minnesota's northern forests and were heavily trapped until the 1970s. Their numbers ebbed and peaked, apparently following the cycles of their favorite food, snowshoe hares.
But after a relative peak in the 1970s, lynx numbers crashed and never came back. The lynx decline appeared to coincide with the crash of hare numbers and other factors, including heavy lynx trapping in Canada. That may have reduced lynx numbers in southern Manitoba and Ontario, which are considered generators for new lynx pushing into Minnesota.
Still, lynx numbers didn't rebound even when hare numbers increased. The state ended trapping in 1984 and the federal government, forced by court orders, added lynx to the threatened species list in 2000 -- not just in Minnesota but across the U.S. Lynx numbers also had crashed in the mountain west and in Maine.
Some biologists said competition from other predators, especially bobcats, might be a factor. Another theory said that global climate change, which is pushing animals such as opossums and raccoons farther north into northern Minnesota, may also be pushing lynx north, out of the state. Lynx have an advantage over competitors with their ability to run on deep snow and catch hares. During low snow years, their competitors can move into lynx territory.
Now, all those theories seem inconsistent with the increase in Minnesota lynx numbers.
``I don't think we really know why we're finding so many now,'' Lindquist said. ``We have more hares. But that's not all of it.''
HABITAT PLAN
It's clear lynx are thriving and reproducing within the state. But researchers still don't know how long they'll stay, or what types of habitat lynx need at different times of year and different stages in their lives.
It's not a simple answer. Lynx can roam over huge areas, especially males. Some lynx trapped near Duluth have been found as far away as Thunder Bay. Yet others remain within a few miles of home from season to season.
``It's likely we'll see crossover (across the Minnesota/Ontario border) all the time. Whether it's lynx born in Canada coming down or lynx born here going north, it's going to keep happening,'' Moen said, adding however, that many lynx stay within Minnesota.
The federal government is paying close attention, paying for the research and forming a plan to protect lynx and their habitat to ensure they won't become extinct in Minnesota. Lynx are being considered, for example, for projects on federal land and were even the impetus for new wildlife crossings in some Minnesota highway projects.
The federal government is under court order to have a lynx habitat plan in place later this year to foster the cat's recovery. The current lynx project report will probably be the basis of that plan. GPS collars on 30 lynx over the past three years have given researchers more than 10,000 location points where lynx have spent time in Minnesota.
Four times every day the GPS collars reveal the location of each collared lynx. Researchers now know lynx hunt hares in thick stands of young forest that have been logged or burned in recent years. But lynx also spend ample time, especially when denning, in woods with big, old trees that block the sun.
Determining how much of each habitat is needed will be critical.
``We're on the cusp of figuring it out,'' Moen said. ``The key will be what the mix is over the long time, what kind of timber rotation and management you need to do to encourage lynx to stay in Minnesota.''
FERTILE FEMALE
Lynx No. 13 has been a productive cat. Since being trapped and fitted with a radio transmitter collar in March, 2004, she had a litter of five kittens last summer and now has four more. Three of last year's kittens are still alive, and one, in a very unusual scenario, is still hanging around with mom.
``It's really unusual for a 1-year-old to still be with its mother. But then, they don't always follow the rules,'' Moen said.
Biologists guess the 25-pound female is about 4 years old. They knew that she stopped roaming and hunting on May 11 and that she was probably having her kittens that day. They waited until the kittens got big enough to handle, not quite a pound each, and then used their radio tracking devices to home in on the mother and the den last week.
She was only about a quarter mile from the nearest gravel road. ``She made it easy for us,'' said Dave Danielson, a Forest Service researcher on the project.
Because of the thick pile of downed trees, and because the newborns are nearly odorless, the kittens have a pretty good chance for survival -- even though hungry bears, wolves and fishers are potential dangers. So far, trains, trucks and traps have been the largest cause of death for radio-collared lynx in the project. Only one has been verified as killed by another animal, a fisher.
``They are notoriously easy for trappers to trap. And they seem to spend a lot of time around roads, . . . and at some point they're going to get unlucky,'' Moen said.
Lynx No. 13 so far has been lucky or wary enough to avoid problems. Now, her ear-tagged kittens will be become part of the same study in which she's been a key element, a study that could determine the fate of her species in Minnesota.
``We're getting generations of lynx for data,'' Moen said. ``We've come a long way in a short time for an animal we didn't know much about a few years ago.''
Originally posted at: http://www.duluthsuperior.com/mld/duluthsuperior/11826986.htm
Posted on Thu, Jun. 16, 2005 - Duluth News Tribune
Lynx weren't gone; they were staying out of our way
Commentary by STEVE LOCH
You can't help noticing, the lynx is back. That's the gist of news reports, including a front-page story in the June 6 News Tribune that featured a half-page photo of the large-pawed, tufted-eared cat.
But was the lynx ever really gone?
Some biologists suggested that lynx were absent in Minnesota until recently, with the exception of a few starving animals that stumbled across the border from Canada . Yet simply because you don't see them doesn't mean they're not there. Surely those biologists were aware that absence of evidence is not evidence of absence.
Lynx live in Ontario, a stone's throw away from suitable habitats in Minnesota . Given that, why wouldn't they be found in Minnesota ?
Carcasses presented to the Minnesota Department of Natural Resources indicate that lynx were present here in the 1990s. For example, three lynx surfaced in 1992 and 1993; another was killed on a road near Grand Marais in 1996; and yet another died in Carlton County in 1997. Tom Rostveit, who lives near the Sawbill Trail, photographed a lynx there in 1995. If lynx specimens turned up at DNR offices during the 1990s, lynx were present.
Furthermore, unlike biologists, some woodsmen were actually paying attention. Bert Highland of Brimson has observed evidence of the cats in northern Minnesota nearly every winter since the 1970s, as has a DNR forester in Cook County and other residents of Minnesota's north woods.
After the animal was federally listed as a threatened species in March 2000, reports of sightings increased. They were photographed in Minnesota on at least three occasions during the winter of 2000-01. Nonetheless, costly hare-snare surveys initiated by the Forest Service in 1999 to determine lynx presence on Minnesota 's National Forests still had not documented the presence of lynx.
Two years after the threatened species listing, a few volunteers used information provided primarily by Minnesota woodsmen to follow lynx trails to a DNA source -- scat -- to verify the animal's presence. They worked in a section of the Superior National Forest between Isabella and Grand Marais. That effort confirmed the presence of 10 lynx and a lynx-bobcat hybrid from samples collected mostly during a few weekends in late March 2002, finally dissolving the "no lynx" myth. A trio of lynx, probably members of the same family, was snow-tracked.
In March 2002, based on this small survey and other evidence of lynx, I estimated no less than 200 lynx were present in Lake and Cook counties. In summer 2002, Joe Foster of Isabella videotaped two lynx families. At least three other families were observed during the fall. Some of these were sighted in the very same areas where lynx researchers are now locating dens. Additional DNA samples collected during the winter of 2002-03, again primarily by weekend volunteers, substantiated the presence of about 20 additional lynx, suggesting the statewide population might consist of 300 to 400 or more.
Yes, lynx numbers have increased in certain areas of Minnesota during the past three years, but they appear to have declined in still other areas. Why?
It is known the lynx population is tied to snowshoe hare abundance. In years past, forest fires, large-scale logging and spruce budworm outbreaks created conditions where hares thrived in the regenerating mixed coniferous forests of northern Minnesota . Hares were abundant, and periodically during the 1970s, dozens, even hundreds, could be counted along roadsides in the north woods. In the mid-1980s, however, their population crashed and did not substantially increase again, as it had in other cycles.
The turn of the century provided hope for lynx with a slight upswing in hare numbers in Minnesota 's current lynx range, at least in certain habitats, though the hare population is still a fraction of what it was in the 1970s. Nonetheless, lynx responded and kittens were produced. The increase of lynx in the past five years can also be attributed to the availability of deer and moose carrion, an important food source when hares are less than abundant. Lynx also occasionally prey on deer, particularly in winters with deep snow.
If there's a mystery involving lynx, it's not whether they were present or absent in Minnesota , but rather how they will fare given the unpredictable future of the snowshoe hares, and whether lynx can be protected from humans so that they may continue to occupy our Minnesota range.
STEVE LOCH of Two Harbors is a wildlife biologist concentrating on the north woods ecoregion of North America who has collected many of the DNA samples confirming lynx presence in the Superior National Forest in 2002 and 2003.
|
||||||||||||
| Your donation is the gift of life, and a second chance for lions, tigers, cougars and more! | ||||||||||||
|
