Eowyn the wolverine

Just heard news from the wolverine folk up in British Columbia that Eowyn, the wolverine we captured and collared this winter in the Methow Valley, WA, was found dead up in Canada. Her remains were found buried next to a Doug fir along with some deer remains. The skull was found with deer bones, and the collar was located nearby. Cougar scat was also around and the buried remains also suggest cougar, so the theory is that Eowyn was found on a deer kill and then killed and eaten by a cougar (who may or may not have originally killed the deer).

It’s always sort of sad to hear about the demise of a being that you have touched, and the counterpoint is always that this is good and interesting data. So it is a mixture of feelings. We do know that she was a young wolverine, so I am sure this sort of mortality is not unusual.

Eowyn during capture in February

Eowyn's skull, photo by Eric Lofroth

skull and deer remains, photo by Eric Lofroth

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Wolverine tracks

I’ve gotten quite a bit of interest on the site from people looking for pictures of wolverine tracks… so here is a collection of photos i took during the season. Some are better than others, and if anyone has questions or comments about wolverine tracks or tracking, i would love to see them.

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Baited camera stations

This was originally posted on the Chattermarks blog:

You would think it wouldn’t work.

First of all, the wolverine is an elusive creature. It inhabits the untrammeled heights of mountain ranges and is rarely seen or documented. So far this season, with ten traps open every day, we’ve captured just one wolverine. We’ve seen few tracks.

But still, this winter we’re trying something new—getting photographs of the chests of wolverines. It’s an idea only recently pioneered by Audrey Magoun, a wolverine researcher in southeast Alaska. And it is a brilliant idea.

Wolverines, it seems, have variable markings of light fur on their throats and chests. So variable, in fact, that each wolverine, if looked at closely, has a unique chest pattern. And therefore, with the right picture, we could tell them apart.

A brilliant idea, truly, but in practice…

It would seem that getting any picture of a wolverine would be a lucky convergence of circumstance, but to get a specific picture—a wolverine in a specific pose, well, it seems like wishful thinking. But then again, most great accomplishments start as silly dreams.

The credit for the accomplishment of this silly dream lies to the north, with Magoun and her team of field people, who took an idea—getting pictures of wolverine chests—and made it happen. We’ve just followed their lead. But it is still exciting.

We come back to the office with a memory card, and John plugs it into a card reader and his computer. The first picture comes up on the screen… of us. It’s a motion-detecting camera setup, and we made sure it was working before we left. But there’s more. Not long after we left, a marten found the site.

This card comes from the first camera set in the North Cascades for this specific purpose. We’ve found that frozen trees are too hard for nails, that pre-drilling is a necessity, and that one drill battery isn’t quite enough. There have been other minor troubles. But the real trouble is that when you’re out there in the North Cascades, you’re out there. There is no stopping by the hardware store for the one more part you need. It’s a drive to a snow park, then a ride on a snowmobile, and then a snowshoe to a site. Forgetting a tool or not bringing enough screws is a disaster, or at least an opportunity for creativity. Sometimes you just make it work.

The setup itself is straightforward. It takes two trees. One holds the camera. The other gets a “run pole” attached to it that leads out to the space between the two trees and facing the camera. Bait hangs in the middle, between the end of the run pole and the camera, but high enough that the wolverine (in theory) cannot quite reach it. The wolverine walks out to the end of the run pole, looks up, and perhaps even rears up, trying to get the bait, and the camera snaps away, taking pictures of a unique chest pattern.

A finished camera station, showing run pole, bait, and camera

This eventuality encompasses a world of minor and major details. Trees the right distance apart. A convenient and sturdy branch from which to hang the bait. The camera not facing south into the sun… all of these factors take time and careful consideration.

On this, the first camera, we spent nearly an hour wandering from tree to tree, looking for the perfect setup. Of course, it doesn’t exist, but we found one that we thought was good enough.

John cycles through the pictures.

We chuckle at the pictures of the marten, who seems to view the bait as a jungle-gym challenge as well as his dinner. In one set of pictures, he swings back and forth, the bottom of the deer leg clamped in his jaws, his body hanging straight down below… the marten and bait swinging freely. In another he has climbed on the bait, and hangs upside down, looking back at the camera. There are pictures of a marten falling, another of him in a mid-air leap. With each picture, the bait gets a little smaller and the marten gets a little fatter.

I am pleased by the pictures. The camera at this station is a model that doesn’t allow us to look at pictures in the field. And therefore the aiming and placement of the camera is a bit of a hopeful venture. Instead of taking test pictures and looking at them on-site, we are left doing our best to aim by eyesight and feel. These photos just catch the bottom of the bait at the top of the picture and the top of the run pole in the bottom of the picture. We guessed pretty well.

John methodically clicks through hundreds of marten pictures, but then stops. “That’s not a marten,” he says. And then we see on the screen a big, hunched weaselish form mounting the run pole against the tree. A lighter stripe contours its side and tells us it is not a small bear, but rather a wolverine.

wolverine captured on camera. Photo courtesy USFS.

Click, click.

“Is that a collar?” John asks.

Within a few clicks, there it is. The picture we could only have dreamed of on the first camera setup of the season, after only a week—a wolverine at the end of the run pole, looking up at the remains of bait. And wearing a GPS collar. Chest on display.

The marten has already taken the bait down to bone, so there isn’t much left and the wolverine doesn’t stay long, but long enough. Two pictures clearly show her chest pattern and that she is wearing a collar.

John scrambles for the trapping supplies and pulls out the laminated photos of the five wolverines captured over the years of the project. Chest photos. One by one we go through them, and there is only one that matches. Xena. Last seen in a trap in the Twisp River three years ago. The batteries in her collar running out about eight months later. There she is, in font of us, looking up at a deer bone near the Cascade Crest. Just a few days ago. Who knew?

the chest shot we're hoping for. Courtesy USFS.

Now, there may be a few of you out there who find yourselves saying, “so what?” And I sympathize with you. Not everyone is as excited about wolverines as we are. And you may wonder what a few chest photos really mean, in the larger sense. Is this really more than just the gratification of a few biologists knowing that an animal they touched and collared is still alive?

Well, yes, as a matter of fact. In the larger sense, this is really cool.

You may have heard of mark-recapture studies. You usually hear about it in terms of rodents or other “expendable” creatures. The idea is that you set up a trap grid, and you mark each critter you capture, so that if you recapture it, you know. In my personal experience, this was live traps set on a grid, and metal ear tags put in the ear of every animal (mouse/vole/wood rat) we caught. Through the wonders of statistics (an arcane magic), scientists smarter than I are able to produce truly insightful conclusions about the size of a population, its fluctuations, and how much its individuals move around.

Think of this on a bigger scale. A camera station as a “capture.” The unique chest pattern as the ear tag, if you will. And maybe, just maybe, you begin to see the wonder and beauty of this technique.

I will say this, too… I believe I speak for most biologists when I say that a hands-on capture of a rare creature is a truly wonderful, once-in-a-lifetime experience. But there is the little voice in the back of your head questioning if the intrusiveness of the procedure, whether the effect on this one, living, breathing, animal, justifies the benefit of the data we will receive. In effect, we trap, ear tag, and collar a wolverine because we hope that the inconvenience and intrusion into its life will help the species as a whole. And although we revel in the personal experience, the musty smell left on the fingertips, we hope, for the individual’s sake, not to have to do it again.

Not that there isn’t a place for trapping. A wolverine tracked by satellite gives biologists an unparalleled insight into how the animal moves, traverses its territory, and uses various habitat types. It also provides the opportunity to pinpoint a den location.

But the questions are more general for monitoring an overall population. How many animals? Where are they? How long do they live? Are they reproducing? These are the questions that, we hope, can be answered by less-intrusive methods, such as baited camera stations.

Out there, right now, in the mountains of the North Cascades. There are baited camera stations waiting. A wolverine walks up, experiments with the run pole, and takes a look at the bait.

The camera clicks away.

Mildly disgruntled, perhaps annoyed, this wonderful, mythical creature lopes away, having never been touched by anything other than the flash of a camera.

And that’s the true beauty of this brilliant, silly idea put forward and acted upon by a wildlife biologist and her crew in southeast Alaska, and now being put to use in the North Cascades.

Xena… right there in front of us. Three years later. Captured, so to speak, without ever having been touched.

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Another Chattermarks blog

I’ve another guest blog posting on NCI’s Chattermarks blog… this one about the baited camera stations we’ve been running.

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On a day in February

Here is the piece I wrote for the Chattermarks Blog about our first wolverine capture of the season, almost a month ago now.  I’ll likely post another or two here in the next few weeks, and will let you know here when and if those go up. Enjoy…

Typical wolverine habitat

It’s the radio call we’ve been waiting for all season. Adam and I linger beside the truck, waiting to unload a couple of snowmobiles and get on with our assignment for the day—setting up our first camera station. But our attention is focused on the Forest Service radio. Waiting. Sherrie and John are up Twisp River checking on two wolverine traps that emit a “closed” signal from their radio transmitters. They’ve checked the first, and found it occupied by a marten. They should be at the second trap at any moment.

After fifteen minutes of fidgeting, kicking at snow, and checking our watches, the radio comes to life. We eavesdrop on static and garbled voices, and finally make out words that change our day. There’s a wolverine in the trap. Our afternoon becomes more interesting. And longer. We pile back into the truck and drag our snowmobiles toward Twisp River.

This winter, ten or more Forest Service employees and volunteers tend ten wolverine traps on the outskirts of the North Cascades. We’ve been at it for two weeks already—replacing bait, checking the function of the traps, dealing with radio transmitter malfunctions, and shoveling snow off of the traps. The status of the traps is checked each morning with radio receivers. We physically inspect and test the traps every three days or so. It’s a fair amount of work, and the crew comes home each afternoon a bit weary and smelling of snowmobile exhaust. So far we’ve caught nothing but martens.

Why all the fuss? Because the North Cascades mountain range is home to wolverines, and we know nearly nothing about them. If you were to quiz a wolverine biologist about wolverines here, you would repeatedly hear the words “I don’t know.” How many are there? How big is a home range? Is it a self-sustaining population? Declining? Increasing? What habitats do they use? Are there threats to their continued existence? A single wolverine has a home range that easily exceeds a hundred square miles of rugged, mountainous terrain. Population density is low. They are extremely difficult to study. And yet land managers are still expected to manage them intelligently.

There are studies from the northern Rockies that fill in some of the basics about the species, but there are always regional intricacies of habitat and population that make extrapolating information about Montana wolverines to a Cascades population difficult.

And so here we are.

Near the trap, John and Sherrie build a flat platform out of the most readily available resource—snow. In a few hours the snow table will be the “operating table” as the wolverine is measured and fitted with a GPS collar. We work quietly, trying to disturb the nearby animal as little as possible.

John wants a second look at the wolverine, and I am eager for a first look, so we approach the closed trap. The sound of our footsteps in the snow triggers a deep, throaty growl from the depths of the trap. This is no marten. It sounds like a bear.

And so we peer into the trap, pointing a flashlight and opening the door as little as we need to. The traps are built of solid timber, and the lid takes some effort for us to lift, but still we need additional mechanical stops on the top to prevent the wolverine from pushing the lid up and escaping. Their strength is legendary.

In the light of the flashlight, her eyes reflect green. She stalks back and forth against the back of the trap. The biologist in me carefully studies the ears and makes sure there is no collar already on her—there are wolverines in the area that have been trapped before and may or may not be wearing a defunct collar, and may or may not still have colored ear tags in their ears. This one’s ears show no signs of tags or tears where tags may have once been. This is what we have been hoping for… a new animal.

But for more than a moment, scientific curiosity pales beside the appreciation of seeing the animal with my own eyes. It is dark and hunched at the back of the trap. A rip in its upper lip shows the white of sharp teeth. Her crouched movement suggests a suppressed rage and indignity. We close the trap and begin waiting.

Patience, I think, is one of the defining qualities of anyone who works with or watches wildlife. There are moments of unbelievable beauty or incredible observations, to be sure, but they are earned by thousands of hours of quiet, slow time.

Sedating and handling a large carnivore is not something to be taken lightly. If there is ever a time for professionalism and organization, this is it. While we lean against our snowmobiles and talk quietly, our boss is on the phone, organizing snowmobiles and trucks and people. We re-read our protocol so that we are prepared for what is to come. The wolverine will be sedated for only 45 minutes, and there is a lot to do in that time. People are assigned jobs and responsibilities. Equipment is checked and re-checked. And we wait.

As a group we gather and talk about the process before we approach the trap. John, my supervisor, and Scott (who works for the state) have been at this for the entirety of the project’s five years, and have handled every wolverine captured. They’ve done it enough that they come with an easy confidence that settles the rest of us. We are given assignments, and we’ve read the protocol, but there is no substitute for having done it before. Of primary importance is the well-being of the wolverine. Syringes are filled and put in pockets with hand warmers, equipment is laid out and ready. The less time we spend handling her, the better, and every minute counts.

And in truth, it goes by in a blur.

John jabs her in the flesh of the hip with a syringe mounted on a plastic pole. We all back off and wait for ten minutes. A peek in the trap confirms that she’s out. Scott reaches in and picks her up—twenty pounds or more of live fury is now lolling and quiet as a bag of turnips. He carries her by me and I note the dark chocolate color and the white-yellow claws on the paws like a mini-grizzly. And the smell. She smells deep and animal and wild… like a bull elk in rut or a bear. I am surprised by this, though I shouldn’t be. One thing weasels are known for their musky scent, and this is the king of the weasels.

Immediately, we are into the handling of the animal. Adam and my assignment is to keep track of the wolverine’s vitals. Every ten minutes we take her body temperature, count her heartbeats, and record the number of respirations. An animal under anesthesia is at the mercy of her handlers; she cannot even regulate her own body temperature. We are ready with hand warmers and blankets, but thankfully she stays within the parameters of a healthy animal.

Eowyn, the first capture of 2010, fitted with GPS collar and ear tags. And Adam.

We weigh and measure her. John injects a pit tag between her shoulder blades, giving her a number that can be read with a reader, just like many people do for their pets. And most importantly, we fit a GPS collar on her. For the next eight months or so (until the battery runs out), this collar will connect with orbiting satellites that pinpoint her location and transmit it. E-mailed GPS locations arrive at John’s desk and are promptly mapped. A wonder of technology.

At about 40 minutes she gives a kick or two, and there is time for a few posed photographs before we put her back in the trap. John injects her with another dose that counteracts the sedative. We close the lid and move away. And again we wait.

On a good day, the sedative wears off in an hour or so and we can release the wolverine. Today fades into tonight as we wait for two hours before she is ready to go. John and Scott wait until they see her acting “normally” in the trap—walking without wobbling and biting and snarling like a wolverine should. Anything less is unacceptable. The last thing we want is to release her when she isn’t ready.

When she’s ready she bounds out of the trap. She bounds for ten yards or so, but then stops to look back at us… perhaps gauging which of us she should kill first, but then thinks better of it and slowly walks up the hill. Green eyeshine, a slow, hunched walk. One of the most wild animals in the Pacific Northwest, and one of the rarest to see.

It is then that I sniff the tips of my fingers and smell wolverine. This is the first wolverine I have ever seen. How many people have seen a wolverine? How many have touched one? I feel truly lucky. And in a stunned moment, I realize that this is part of my job. The hours of snowmobiling, shoveling, and checking empty traps that have passed and are yet to come are suddenly a small measure against the privilege of touching something wild, beautiful, rare, and free.

And I am unafraid to tell you that I feel a personal connection that her cut lip and scar, the stink of her, and the unique pattern of color on her chest only help to reinforce. I have touched this animal.

—–

It has been ten days since that wolverine, whom the people in charge are calling Eowyn for our own sake of keeping track of her (I’m sure she has her own name) touched me. Every morning the first question in the office is “where is she?” And when we point to the map, I smell the stink of her on my fingers and remember the bale in her eye.

Until that collar’s battery fails, she is giving scientists a glimpse of how a wolverine uses the landscape, how she travels, and how much space she needs. This is all important information for people and organizations that need to manage wolverines in the Pacific Northwest. If there is a hope for the species, in the face of human expansion and recreation in wolverine habitat, in the face of a warming world that threatens the existence of the persistent snowfields on which they depend, it is in these data points.

At some point last night, Eowyn crossed the border into Canada. It is miles and miles and miles of the heart of the North Cascades between Twisp River and Canada. Steep, rugged terrain that would challenge the best of us. Ten days for her. Where is she going? What is she thinking?

wolverine tracks, probably Eowyn, crossing the Twisp River

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A picture is worth thousands of your paltry words

So, as the progenitor of this digital collection of words and images, I have the unique opportunity to see how people get here. One thing I notice is that as I write about wolverines, folk keep finding this site by seeking photographs of wolverine tracks. Well, give the people what they want, I say (it seems like someone else might have said that first).

But not quite yet.

Instead, tonight let’s take a real good look at one picture.

Here’s a photo I took while standing on the seat of a Forest Service snowmobile in the vicinity of Hart’s Pass, WA. You wouldn’ think the tracking conditions were good. A week or more of sun and warm temperatures preceded this day. The snow was a concrete slab, with only hoar frost to provide softness to the surface… and the balm of the midday sun. But at night it would freeze again. So there was a chance at tracks, but only at the right time of day. Well, we got lucky.

Wait, you say, that’s two pictures! Well, not really. The first is a little closer on the wolverine track and the second gives you more of the bigger picture and scale.

Speaking of scale, let me apologize to the tracking community. I know, I know, when I’m taking photos of animal tracks, I’m supposed to put a tape measure in the picture so that everyone can compare it to the various charts that trackers have laboriously come up with to classify animal tracks. Well, sorry to buck tradition, but I think that a tape measure ruins an otherwise artistic masterpiece of a track in snow. And furthermore (sit down for this one), I suggest you throw away your tape measure altogether! Feel the ripples of indignation spreading from the audacity of that statement…

But seriously, there is a place for precise measurements. Maybe in telling a fisher from a marten. But in most cases, to concentrate on measuring track, stride, and straddle is to meticulously look at a tree when the forest could tell you what you want to know.

With that in mind, lets look at our picture. Here’s what I mean about throwing away the tape measure… compare the track and stride size to the snowmobile track next to it, and the result is … it’s big. Not a mouse, not a squirrel, not even a marten. Big, I tell you. We’re on the edge of the North Cascades in Washington… in winter. So big makes our job easy. It’s winter, so bears are out. Lynx, wolverine, wolf. That’s about it.

And so we take a close look.

Lynx falls out real quick. Cat’s have retractable claws that don’t show in the snow. And the individual tracks are asymmetric. Asymmetric? you say?… well, the direction that the pad seems to be pointing and the direction the toes point isn’t quite the same. It’s like they’re pigeon-toed, if that helps you imagine. Plus, they only have four toes.

Look at the photo. Counting individual tracks from the bottom–track 1 is the top of a group cut off by the photo, and then we get 2,3,4,5 with 3 and 4 almost superimposed, and so on.  There’s a hint of something in track number 2… and definitely noticeable in 6 and again in 10. A fifth toe. Of our choices, the weasel family is the only family that shows 5 toes in a track. But even if, for some reason, that toe never registered–theres’ another hint. Thank Rezendes for this one… a typical weasel footprint is 5-toed, but pay attention here) the middle three toes tend to group together.. giving a 1-3-1 pattern to the toes. If you look carefully, you can see this in the photo, even where the 5th toe doesn’t register (a -3-1 if you will). Out goes lynx and wolf. But to be fair, let’s pretend we couldn’t see toes.

We can tell even without toes? Hell yes!

But let me be careful here. On a good track, where you can see a definite pad and toes, you only need look at ten tracks or so before you are pretty certain of the animal you are looking at. When looking at track patterns, it takes a little more work. Most trackers will follow a pattern for at least a hundred yards before making a guess, and even then will be open to other opinions. But some guesses are better than others. And that’s the point… to make an educated guess.

Take another look at the photo. No matter what it is, it is a four-legged creature. So how do the four legs fall? Track 1 is the top of a grouping, so ignore it for now. 2,3,4, and 5 are the four feet landing. How do they land? Well, kind of slanted. And 3 and 4 nearly land on top of each other. Well, folks, what we are looking at here is a classic weasel track pattern. The slant can be right or left, but 4 tracks end up looking like 3 (especially in deeper snow, where the second and third almost direct-register). From an earlier post, here is the two patterns I have seen from a wolverine:

and therefore the track (the right pattern) is called a 3x track pattern (though it is 4 feet). The track pattern in our photo is slanted the other way, but you can still see it.

And there’s more. Take a look at the scratch marks in the snow between tracks. Not only can we see the tracks and track pattern, but we can almost match individual tracks by the toe drag between them! (Please don’t discourage me by rolling your eyes, I’m having fun here). My hero, Rezendes, was kind enough to point out that you can tell hind tracks from front tracks in the weasel family–the hind tracks register toes and a pad, while the front tracks register toes, pad, and an elongated impression of the leg coming into the pad. Look at the picture… you can see this. Two tracks have an elongated pad while the other two are concise tracks. And then look at the toe drag… you see where the rear feet land and where the front feet land. So… the track pattern, as i see it,  is front-(rear-front)-rear. Though the toe drag in the middle tracks is a little muddled, you can see that the lone rear track and the lone front track connect… so the lead foot remains the same throughout the travel! You may think me a dork for being impressed by this insight, but suddenly I can imagine the animal moving… the strange, hunch-backed lope of a weasel… and it all makes sense. And suddenly we connect, the wolverine and I. As if I saw it loping along with my own eyes.

And so maybe you begin to see my celebration of one paltry photograph. But I’m not quite done yet.

What is that above and left of our wolverine track? In the snow there is an old, melted-out track pattern. The quick look is one that would have the sane person saying “not a good enough track, you can’t tell what that is.” And they would be right. Except if we were asked to make an educated guess.

Back to basics. No toes showing. Measurements near to useless. It’s melted out and old. But then again…

It’s a big track, even if melting has exaggerated it. And the lower half of the picture shows a slanted 2x pattern… classic weasel. And the upper part of the picture goes into a slanted 3x pattern… again a weasel pattern. Not definitive, i suppose, but all fingers are pointing away from lynx and wolf and toward marten or wolverine. And… I’ll put my own experience on the line a little here… the wolverine tracks I’ve seen freely switch from 2x to 3x without warning, whereas marten tracks tend to stick to 2x patterns unless they slow down to look at something. This one switches back and forth while traveling a road grade. And it is probably a big track. I f a PhD were to ask me if this (the old track) was a wolverine track, I’d say “probably.” (it doesn’t really matter, they wouldn’t believe me anyway). But if someone were to ask me where to put a camera station or wolverine trap, I would, with confidence, put my finger down on the map… even with just seeing the old track. And you could, too.

Drop the measuring tape. Take a look at the big picture.

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wolverine capture

I’m a “special guest” blogger on North Cascade Institute’s Chattermarks Blog this week if you want to check it out. It’s a short piece about our wolverine capture earlier this month.

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Putative bobcats seem quite lazy

Putative seems to be the new word in the carnivore world. On going over protocols for tracking wolverines this season, every track is considered a “putative” wolverine track. Which is why there is now a heavy emphasis on collecting hair and scat. DNA gleaned from these samples will allow a putative species track to become a confirmed species track. Apparently they don’t think that their field folk can tell a wolverine track from a lynx track. In some cases they are probably right, but I can’t help but feel a little insulted. I’m pretty sure I could tell a good wolverine track from a good lynx track at 25 mph on a snowmobile. In their defense, the world of the PhD is one of lawsuits and defensible science, so perhaps they can be forgiven. But I was supposed to be talking about a bobcat before that putative word got in the way…

Today I discovered an excellent bobcat (putative) track. It was fresh and unchanged by the sun above me. The toes stood out sharp in the snow, slanted like a cat–asymmetric some might say. The feet sank into the snow just enough to leave a track… maybe a quarter inch or so. Great conditions, and a track that looked like the bobcat was just around the corner.

Part of getting good at tracking is to take advantage of opportunities where you have a good track. Putative PhD’s aside, I knew after looking at the first print that this was a bobcat. But still, it pays to look at the bigger picture. It lets you imprint the intricacies of track pattern, stride, straddle, etc. into your mind so that another time, when the tracking condition aren’t good, you can pull it back out and make an educated guess. Kind of like orienteering… you don’t wait until you’re lost to look at the map–you still look it even though you know where you are.

So I looked at the whole track–there was probably 40 yards or so of bobcat trail in a nice, open area. The first thing that registered was that this was not what I am used to seeing in a cat pattern. Cats spend the majority of their time in a very concise and predictable alternating pattern. But this was different… sort of like an alternating track with two prints on each side. Sigh, maybe a diagram would help:

a normal, catlike alternating pattern (left) versus this putative bobcat track (right)

And then, where the cat (putative! I hear them yell…) made a couple of turns it all went to hell… at times it looked even like a weaselish slanted set of four prints (though a weasel would superimpose the middle two on each other to show more of a 3x slant rather than a 4x slant). I heard or read (I paraphrase) that every animal will at some point leave a track that looks exactly like a different animal — it was probably Rezendes again. So I looked at a few more prints… 4 toes, asymmetric, no claws… a bobcat, no doubt. Screw the scientific scrutiny. Just a different track pattern than I’m used to, and therefore a learning opportunity. More pictures:

Kind of interesting if you’re a track nerd like me, but nothing new. Rezendes notes it in his book as a “fast walk” and even shows a slanted 4x pattern as a “lope” for a bobcat (did he have DNA confirmation, one wonders…). But it’s fun to see and discover for yourself.

And in looking at the overall pattern, I suddenly noticed all the drag marks. This cat was dragging toes on every step! Now, Rezendes also notes that bobcats commonly drag their toes in the snow, but when I read this, I assume he is talking about measurable snow amounts. In this case, the animal was barely sinking into the snow at all. Like I said, maybe a quarter inch–and still dragging its toes. As if lifting its feet was such a chore.

It is these little moments that make being outside fun. A little connection with the animal, something different. Not your average bobcat, but the laziest one in the state. It put a little smile on my face and led me to the obvious conclusion — putative bobcats are lazy.

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Tracking the wolverine

from http://gulo.udev.org/gulo.php3

Arriving at work on a morning this week, I was asked “how do you feel about following some wolverine tracks today?” The good news was that we had definite evidence of a wolverine visiting one of our trap sites, the bad news was that the trap was closed when the wolverine swung by. Martens are a challenge for us–in this case one was already in the trap, probably munching on some bait, when the wolverine passed by. At about the same time another wolverine had visited a trap at Harts Pass and found it closed, too. That one was closed because of some technical difficulties with the radio telemetry that tells us whether the trap is open or closed.

Despite our disappointment (getting a GPS collar on a few wolverines is the goal for the winter, after all), there was something we could accomplish. Believe it or not, we had a chance to know exactly who this wolverine was.

Technology has had a profound effect on the study of wildlife. GPS and GIS allows wildlife biologist to see the location of collared animals from the comfort of an office chair. Pit tags allow us to know the identity of animals (salmon, bats, and even beavers) as they pass by readers along rivers or at cave entrances. GIS allows biologists to see a wide variety of maps that catalog forest type, soil type, elevation, and about as many others variables as you can imagine. Batteries and GPS units continue to get smaller, allowing the use of GPS tracking on smaller and smaller animals. And then there is DNA analysis.

Believe it or not, the goal of our tracking the wolverine on this day in January was the hope that we would find… scat. It used to be that the only reason biologists were poking and prodding at these basic bodily functions was to discern the peculiarities of diet from what passed through the intestine. But now there’s something else. DNA.

It seems that when an animal (and that includes us) takes a shit in the woods, there is a trace of intestinal cells that slough off in the process and find themselves lingering on the surface of scat. These cells, when the scat is properly collected and delivered to a lab, can be teased off and analyzed, giving the DNA footprint of the animal. Species, sex, and even individual can be identified from these samples. It’s pretty amazing.

Ten years ago, I was in this area tracking Canadian lynx during the winter. I was paid to carry a heavy, accurate GPS unit to record the trail of the lynx and any associated behaviors. One of the things we did was to collect scat and hair as we found them. This was in the early days of this lab technique, and the lab biologists were surprised and encouraged by what they could tease out of our samples. Now there is a movement (no pun intended) to use hair and scat collection as a means of monitoring otherwise elusive wildlife populations. Like the wolverine.

Although I had once seen a snowed-in wolverine track during my lynx-tracking days, this was my first opportunity to spend time with a good track. It was a lot of fun. For those of you who are trackers, aspiring trackers, or just interested, here are some of my photos and observations:

The track itself seemed pretty distinctive, if you’ve looked at a few tracks in the snow. The feet are large compared to the size of the animal, so you get large tracks with a relatively small stride and straddle. You might confuse them with a wolf, but the stride is much shorter, and the same for a cougar.  And the track pattern is different.

If you can see toes, it is easy. The weasel family has five toes that show in a track, and the middle three toes are closer together than the outer two, giving what is called a 1-3-1 pattern to the toes. A picture might help:

Note also the the claws clearly show in the track, which means it is not a cat.  The marten is in the weasel family, and could be confused with a wolverine, I suppose, but the marten track is much smaller, whereas the wolverine track was about the size of the palm of my hand (according to Halfpenny, the wolverine averages a 4″x4″ track, while a marten is 1.75″x1.75″). The toes also seemed much more distinct than in a marten track, as if the marten has furrier feet. Another picture with my snowshoe and foot for scale:

Note also how the heel of the wolverine seems to lay down into the track, making it look elongated. We were lucky with snow conditions–there was a little bit of new snow on top of a hard, older layer. These pictures, taken where there was less snow under the trees, really gave a good look at the pattern of the foot, as opposed to in the open areas, where the snow obscured more of the detail. A good lesson in tracking is to always follow an unknown track for a ways before deciding what it is–it may look very different at the roadside than it does further along, and it is better to develop a mental image of the usual track pattern, size, and shape and to morph these into an “average” track and pattern in your head.

And before we move off into the snow, here’s a couple of photos of John, my supervisor, creating some “wildlife paperweights” as he calls them. The red stuff is a spray-on wax that keeps the plaster of paris from melting the snow (and therefore the track)… the wax is commercially available, and the plaster is very available, and you end up with a cast of the track. His were slightly soft after a couple of hours, but ready to be moved.

The wax also seemed to make the tracks show a little better in these pictures…

Moving out from under the tree cover and into some deeper snow, I was surprised that the tracks didn’t show more drag from the wolverine’s body. Although the tracks were a little messy (kicked snow, dragged toes, etc) they were cleaner than i thought they would be. This can be different in different snow conditions, though.

Since these tracks I have seen some in powdery snow at Harts Pass, and there was a bit of a body trench involved in those tracks.

Represented here are the two track patterns I noted while following this wolverine. They are standard track patterns for the weasel family, and I believe are referred to as the 2x and 3x patterns. I was surprised, in following this critter, how often and easily the wolverine switched back and forth between these two patterns. There didn’t seem to be much difference in the speed of the animal, although in my mind the 2x track seems more suited to a faster travel. The real key to knowing this is to see the length of the space between track sets (the stride) increasing. But the stride on the tracks I saw seemed comparable in the 2x and 3x patterns. Also of note is that the animal seemed comfortable changing the lead foot, so sometimes the tracks were slanted right (as in my representation to the left) and sometimes slanted left. It’s fun to know, too, that the 2x pattern is actually 4 feet landing in each set of tracks… the lead feet have already left the track when the hind feet land in the same spot.

Some more photographs:

A 2x track pattern in the snow.

A 3x track changing to a 2x track.

“Being a weasel” … he/she was checking every tree bole on the way up the hill. Looking for squirrels? hares?

The wolverine crosses the river. Notice the track pattern and how the lead foot has changed from the foreground to the most distant tracks, and that there are a couple of 2x strides before going back to 3x…

In the end, we got what we were looking for. One team backtracked and the other forward tracked, and although neither group collected any hair (DNA can also be gleaned from the follicles when hair get pulled out of the animal), each team did recover a turd. A couple of wolverines have been trapped in this vicinity in recent years, and DNA is taken when they are trapped, so when the results come back from the lab we’ll know if the animal we were tracking was one that had been caught before, and if so, exactly which one. Pretty neat.

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Weasel and Marten, take 2

For the next few months, I’m maintaining wolverine traps and baited camera stations in the North Cascades of Washington. It sounds glorious… news of my duties prompted a friend to write “I hate you Dan.” And it is. And it is also tiring and hard work. I spend my days shoveling the traps out, and pulling and tugging on stuck snowmobiles. Still, on nice days, i sometimes feel guilty for being paid to be out there.

But to get to the point… i wrote a bit ago about the difference between weasel and marten tracks, and to close a circle–in the last two days i have laid eyes on both creatures. Yesterday a beautiful weasel–white save for a black-tipped tail, was started by our passing snowmobiles, and after scrambling across the snow surface for twenty feet or so, decided to duck his body below the snow to hide. His head popped out for a peek a few seconds later. His motion seemed slow, but at the same time was much faster than any of us could have managed in the foot or so of powder he was skipping over.

And today the phone rang at 7 am (the horror!) with the message that our boss had traps giving the “closed” signal on radio telemetry and he needed people to go check them. Admittedly, i don’t have much of a social life, so i had no other plans for a saturday and soon found myself on a snowmobile headed to check two traps. We’re trying to catch wolverines, but they are rare to catch. More often, it is martens (American pine marten?) that trigger the trap. They sit in there and chew away contentedly on the provided deer or beaver and patiently wait for a biologist to come and open the door for them. Sure enough, that’s what we got. Good picture, though. Cute critter.

So from paired tracks to paired animals. Life is good.

A few days later we found the same marten in the trap again. This short video is a bit amusing:

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