Mythical Beast

“I was at 10,000 feet or so,” says wildlife researcher Phil Manlick. “My friends were fishing on one side of an alpine lake, but I was sleeping, and facing the other direction. I opened my eyes and saw a wolverine running across a snowfield on the north side of the canyon. First, I gestured wildly, trying to get the group’s attention. Then I yelled. They still didn’t hear. One of the group had been talking all week about how much he wanted to see a wolverine, so finally I shouted his name, ‘ALEX!’ at the top of my lungs. Either the wolverine was named Alex,” Phil jokes, “or I disturbed him a bit, because the large weasel stopped and looked at us. Then the wolverine turned and ran straight up over one of the highest passes in the Tetons, right into Idaho.”

Phil has researched various animals all over the country, from elk and mule deer in Oregon, to cougars and grizzly bears in Washington. He has tracked wolves in the Grand Tetons, and now pine martens in Clam Lake, WI. But from the excitement he shows in his face, voice, and even gestures as he tells this well-worn story, you can tell that this was a highlight of his animal encounters.

And it’s no wonder. Wolverines are among the most elusive creatures on the planet, and have become an almost mythical beast. As the largest land-dwelling member of the weasel family, wolverines take weasels’ reputations for fierceness to the highest level. By some estimates, if a wolverine were the size of a bear, it would be the strongest creature on Earth. It is no exaggeration that the wolverine is the strongest animal of its size.

With this strength of body and of will, wolverines live in some of the toughest terrain – the most rugged, remote and fiercely raw – and can prey on large animals like deer, moose, wild sheep, and elk. Wolverines are opportunistic feeders that also eat carrion, smaller mammals, eggs, roots, and berries. Food in their harsh habitats can be scarce, so they have adapted to a feast-or-famine lifestyle by reportedly eating up to 40 pounds (their own bodyweight) at one time when food is available. This earned them the scientific name Gulo gulo, which means “glutton” in Latin.

Even rock-hard frozen food doesn’t present a problem to wolverines, since they, like other mustelids, possess a special upper molar in the back of the mouth that is rotated 90 degrees, towards the inside of the mouth. This special characteristic allows wolverines to tear off meat from prey or carrion that has been frozen solid.

This and other adaptions give wolverines an advantage in winter. Big, padded paws help them run through deep snow, and a relatively large, compact body and a thick winter pelage minimizes heat loss. Their dark, oily fur is also highly hydrophobic, making it resistant to frost. Humans in many cultures have taken advantage of this trait by using the fur to line jackets and parkas. Scientists estimate that wolverines do not experience cold stress at even negative forty degrees Fahrenheit.

Wolverines seem tough enough to withstand almost anything. And yet, their population in the United States declined precipitously by the turn of the last century, and is still declining today. Poisoned carcasses and fur trapping precipitated the initial decline. A completely different set of stressors acts today.

Spring snow cover through mid-May is essential to wolverine reproduction, since females raise their kits in snow dens that provide protection from the cold and predators. In fact, spring snow cover is the one factor that all wolverine habitats across the continent have in common. Although Wisconsin has not had regular spring snow cover recently, scientists surmise that the Little Ice Age from 1350 to 1850 may have provided better habitat for wolverines here before accurate records were kept.

The distribution of current wolverine records in the contiguous United States is limited to north-central Washington, northern and central Idaho, western Montana, and northwestern Wyoming, although rare sightings do still occur in the Great Lakes region. The wolverine was on Michigan's endangered species list until the late 1990s, when it was removed from the list because it wasn't expected to return. 

Although the wolverine is a candidate for the Federal Endangered Species List, its main threat is a warming climate, which cannot be addressed under the current Endangered Species Act. A National Center for Atmospheric Research study found that “Unless the wolverine is able to very rapidly adapt to summertime temperatures far above anything it currently experiences, and to a spring with little or no snow cover, it is unlikely that it will continue to survive in the contiguous U.S. under a high or medium-low carbon emissions scenario.”

The good news is that if we can reduce our emissions to the lowest emissions scenario, we can make help these mythical beasts survive in the Tetons, not just in legends. Phil would appreciate that, and so would his friend Alex.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The current exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

 

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.

Moose Tracks and Trends

A few inches of crusty snow reflect the sunshine brightly, and the sounds of dripping icicles fill the air. A stiff breeze tousles my hair, but even that is not enough for me to put on a hat. Thirty-one years ago today, my birthday, a blizzard howled through the Midwest, and my parents were lucky that a short break in the storm allowed them to get safely to the hospital. Today, in only a sweater and jeans, I am overheating like crazy. Mittens dangle in my hands, and my windbreaker flaps around my waist.

 

This warm spell triggers a little daydream about canoe season. My mind drifts back to a calm August morning near Long Island Lake in the Boundary Waters. It was the first portage of the morning, and as we slid up on the smooth sand, we noticed that someone else had been there first. Someone with six-inch long toes, two per foot, shaped like a mirrored pair of commas.

 

Thinking of the large, gangly moose that made those tracks takes me back to a very different adventure in the Green Mountains of Vermont. I was snowshoeing up through a drifted alpine glade with some classmates, and we came upon a moose trail. The moose’s feet had punched huge round holes in the snow’s crust, which destabilized it. The fractured crust could no longer hold us on top either, and we sank through up to our hips.

 

The depth of the snow did not seem problematic to the moose. Moose’s bellies are about 35 inches off the ground, twice as high as a deer’s, and just about up to my waist. In addition to having a height advantage, moose can lift their front feet nearly shoulder high, enabling them to travel easily over fallen trees and through deep snow. Hollow insulating hair and a huge body mass (1,000 pounds easily), combine to make them well adapted to cold, snowy winters.

 

We clumsily followed the tracks for a little bit, and in one shrubby opening I noticed a strange pattern. The moose’s footprints went on either side of a 10-15 foot-tall mountain maple. Why was the moose straddling a tree? I grabbed as high up as I could and bent the top of the flexible sapling down to eye-level. Sure enough, the tips were torn off raggedly, a result of the moose’s lack of upper incisors. The huge herbivore was walking over shrubs, bending them underneath its huge belly, and then munching on the most tender buds.

 

Have you seen a moose in Wisconsin lately? Probably not. You’re lucky if you have, since only about 20-40 remained in the state as of 2003. Historically, moose were common in the northern third of Wisconsin. Hunting, habitat change, and competition from deer caused their extirpation in the early 1900s. Moose from Michigan and Minnesota have since wandered back into our state, but have not established a significant population. The two primary reasons, according to biologists, are a lack of habitat and relatively high deer numbers. Deer carry brainworm, a parasite that can be tolerated by deer, but that kills many moose.

 

It is days like today that make it harder for moose to live here or in neighboring states. In winter, moose tend to exhibit heat stress at 20 degrees Fahrenheit. When the entire winter is warmer, moose are stressed all season. Higher temperatures in the summer are no better.

 

Add this to the fact that the moose’s pests like mild winters, and you have a problem. Biologists are now documenting individual adult moose infested with from 50,000 to 70,000 ticks, a ten- to twentyfold increase over what used to be a normal load. The stressors were too great for the moose population in northwestern Minnesota, which plummeted from 4,000 animals in the 1980’s, to less than 100 just a few years ago. In northeastern Minnesota the population has been halved in just six years, dropping from 8,840 animals in 2006 to just 4,230 in 2012.

 

"A variety of factors may be contributing to the decline, but ultimately I think the real driving force is the climate," says Dennis Murray, main author of the northwestern Minnesota moose study. "The climate change is tipping the balance."

 

As I hoof it back up the hill toward home, I can empathize with the moose. Thirty-one is a fine age, but a terrible temperature for January. What little skiable snow we had is melting, my expensive winter gear is languishing in a closet, and all sorts of insect pests are surviving cozily in their warm hibernacula, just waiting for spring. At this rate, they will not have to wait long. Sobering thoughts for a warm, sunny, birthday walk.

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The current exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

 

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.

Big Furry Snowshoes

 

Skis swished and our breath came out in puffs of white as we traveled through a majestic corridor of snow-laden fir trees. We looked up to a bright blue sky, but on either side of the trail the young evergreens grew tightly packed together, each striving for just a little more sun. Thinner snow under the trees recorded the comings and goings of snowshoe hares.

 

As the firs gave way to a mixed coniferous/deciduous forest at the trail intersection, small maple and dogwood saplings dominated the understory. The shortest of the shrubs were trimmed to stunted twigs with sharp-angled tips. These little bonsai trees are a result of hares browsing vegetation with sharp, ever-growing incisors, similar to beavers. In contrast, nibbled-on twigs a meter high bore tips shredded by the coarse lower teeth of deer.

 

Snowshoe hares are well adapted to harsh, snowy winters. Their huge hind feet help them float on top of the snow, and their seasonally white fur lets them blend in.  The hare’s pineal gland (which even in humans produces melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions) senses changing photoperiods in the fall and spring, and triggers the color transition between brown in summer and white in winter. It takes about ten weeks for the change to be complete, and if the hare is not on schedule with the weather, it may stick out like a sore thumb.

 

So, like us skiers, hares may not fare so well in our warming and less-snowy future. Scientists at the University of Montana are studying the hare’s predicament, and asking questions like: “Will hares continue to shift coat colors on cue, regardless of the presence or absence of snow? Will this drive them to extinction? Or will they be able to adjust their seasonal pattern in time to fit new conditions?” There is evidence that they can adapt varying snow amounts -- not all snowshoe hares change color – some in the far north stay white, and some in Oregon and Washington stay brown.

 

“Hares are important because they are prey for almost everything in the forest that eats meat,” researcher Scott Mills said. “Without hares, the ecosystem unravels.”

 

One predator who is particularly dependent on snowshoe hares is the Canada lynx. With its own set of huge, furry snowshoe paws, extra-long legs, and warm fur, the lynx can out-compete other mid-sized predators in areas with deep snow. And I do mean deep. Lynx thrive with an average annual snowfall of almost nine feet.

 

Fur trapping records going back hundreds of years show that the lynx numbers rise and fall on a cycle of ten years, two years behind the snowshoe hare population cycle. At least they did. The lynx population in Minnesota stopped following the hare cycle closely in the 1980’s.

 

Lynx have never been common in Wisconsin, but since 1900, lynx sightings in our state have occurred when the 10-year cycle of snowshoe hares in Canada has crashed. (When this happens, the animals have to wander farther to find food.) But a lynx hasn’t been spotted in Wisconsin since 1992.

 

With less snow on the ground, lynx lose their advantage. It becomes harder to compete with other mid-sized predators like pine martins, fishers, and coyotes. The lynx’s own cousin, the bobcat, is its fiercest competitor. These days, where you find bobcats, you just do not find lynx.

 

It is hard to imagine that the world is warming when your chin feels like it might freeze off, and your fingers and toes are numb. I tried to ski faster to warm up, but uneven bumps in the trail, shallow tracks, and a few thin rocky places made it hard. With only ten inches of snow in the woods, the North Shore of Minnesota was just barely skiable on New Year’s Eve.

 

Still, a slower pace made it easier to check for animal tracks along the trail. I co-taught a biology class that tracked wolves and lynx up here during the winters of 2005-2008, and I just can’t break the habit of tracking as I ski. One of our students found a lynx track near here in 2008, and we shared our data with the Natural Resources Research Institute in Duluth, which has radio collared over 33 lynx since 2003.

 

On this day, we found a perfect print where a wolf had crossed the freshly groomed snow. I slowed a bit to peer over my shoulder at another animal trail, but thought it was just a deer. Then my fellow skiers stopped too, and pointed out four tiny toes in a lopsided C shape, and a three lobed heel pad. No claw marks tipped the toes, and no fur obscured the details in the shallow snow. The whole track was just an inch and half wide. Bobcat.

 

Skiers, snowshoe hares, lynx. We all LOVE winter. During Birkie week, the Museum is creating an exhibit called “We LOVE Winter,” that will highlight the fascinating winter adaptations of animals. Come visit, learn more about critters who share your love for winter, and gain a new appreciation for this challenging and delightful season.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

 

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.

Awake and Wondering

Fox tracks crisscross my yard. Down the trail to the lake, along the lakeshore, across the hill in one direction (stopping at a tiny pine tree to mark his territory), and then back across the hill on the diagonal (making that poor little pine tree the center of the X). The strings of tracks remind me that I’m not the only one who lives here. These woods are alive, even under the blanket of snow and the low-slung stars. I try to read the fox’s nocturnal adventures in the tracks, to guess at his life in the forest, but so much of nature, especially at night, is still a mystery.

 

We have just experienced the longest night of the year, and for six months now, the nights will shorten again, giving way to the day. Winter solstice has always been a time to rejoice in the returning of the light. People from all over the Earth and throughout the span of human time have celebrated with food, fire, and forgiveness. Though the longest nights have passed for this year, we still have many more long winter nights before the light and dark find balance at the equinox.

 

Have you ever wondered what happens out there, under the heavens, while you sleep? I went to bed last night with a crystal-clear sky, stars sparkling like diamonds in the plummeting cold. This morning I woke to a blanket of clouds, a dusting of snow on my windshield. When did the clouds roll in? What did the snow look like as it fell? Who was out there to see it? Was the fox trotting along thinking, as poet Mary Oliver infers, “It is music to wander the black back roads/outside of town -- no one awake or wondering/if anything/miraculous is ever going to/happen, totally dumb to the fact of every/moment's miracle…”

 

The sparkle of hoar frost (from the Norse hārr, “gray with age”) on the trees this morning certainly makes it seem like something extraordinary transpired last night while no one was awake and wondering. Extraordinary, but still explained by chemistry and physics. As the temperature dropped below the dew point, water was squeezed out of the air. In this case, the dew point just happened to be below freezing (therefore it is technically called the frost point), so water precipitated as ice on cold objects instead of condensing as dew. The frost crystals often form intricate patterns that scatter light, making them appear like a white frosting on all the trees, as if the world is made of glitter.

 

Down the trail to the lake, along the lakeshore, I make my own tracks. Two parallel ribbons stream out behind me as I ski on the frozen lake. Hoar frost carpets the thin snowpack, and miniature forests of crystals glitter on patches of wind-swept ice. Fox tracks are everywhere. A loud pop and eerie wail sound from the ice. As the temperature drops, the ice expands and fractures. I can trace the path of the crack with my ears.

 

Thin ice acts as huge membrane across which the crackling and popping sounds spread. One website, devoted to recording these ice songs, (Search “silent listening ice recordings” to find it) explains that: “The high frequencies of the popping and cracking noises are transmitted faster by the ice than the deeper frequencies, which reach the listener with a time lag as glissandi (a glide from one pitch to another)” Science explains even the marvel of ice singing.

 

Tonight I am feeling the music of wandering the back ways outside of town. Moonlight glitters, ice sings, our planet spins toward the light. Though science can explain them all, there is still room for wonder. For example, science cannot reveal the thoughts of a fox. We leave that up to the poets.

 

Tonight I, and maybe you, and maybe even the fox, are awake and wondering.

What is this moment’s miracle?

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

 

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.