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Archive for January, 2010

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:

wolverine track

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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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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The Touch

Tonight, sitting at a bar, a waitress i vaguely know was passing by when she took the time to grab my arm and say hello in passing. More than a touch… the half-close of fingers around the space where my bicep meets the elbow on my left arm. As one who is always short on spoken words, i take some stock in the meanings of action… and of touch. I have been touched this way before–it is somewhere between the pat on the arm or shoulder (harmless, friendly contact) and the touch the arm or the hug that lingers to the point of enhanced meaning.  What is the “bicep grab?” Is it a way for a curious woman to measure the manly muscle mass of a prospective mate, or simply a different way to say hello?

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Untimely

Is there ever a timely death?

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So I just finished reading Lolita by Nabokov and was duly impressed. It is a disturbing novel and a beautiful one, and very well written. I like how Nabokov crafts it so that our dislike of the narrator grows throughout the telling of the story. And I like the language…

“Poets never kill.”

“One drop of rare honey, however, that Thursday did hold in its acorn cup.”

“Most of the dandelions had turned from suns to moons.”

And is often the case with “literature,” I was forced to read with a companion dictionary by my side. Here, for fun, is an incomplete list of Nabokov’s words that sent me floundering into the dry pages of the dictionary:

poltroon, expiate, atavistic, paroxysm, restive, ennui, favonian, meretricious, phocine, nacreous, concomitant, seraglio, incondite, preprandial, eructations, neuralgia, ecru, duenna, porcine, lentor, leporine, crepitate, apotheosis, dulcet, charwoman, remise, insouciance, logodaedaly, logomancy, undinist, ancilla, selenian, auroch.

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Took some photos a few weeks back while snowshoeing, and thought maybe i should share them for anyone interested in snow tracking and telling the members of the weasel family apart. I will soon be doing some winter work with wolverines, so hopefully i’ll be able to add some wolverine track photos later on.

The photos are particularly useful (i think) because i found a spot where weasel and marten crossed paths, so a comparison was particularly easy.

But first the weasel solo — the leatherman measures 4″ long, to give you a sense of scale:

Halfpenny calls this type of track “2x bounding”… each set of tracks here is actually four footprints–the front feet land, but then are already in the air when the rear feet touch down in the tracks left by the front feet. If you want to hear about measurements, check out Halfpenny or Rezendes (both excellent books with a slightly different approach). For me, though, notice the width of the track in comparison to the length of the bound–you can see that it is a long bounding pattern. If you are to follow a weasel track, you’ll also note an erratic trail–these guys tend to zig and zag and are unafraid of going under the snow for a bit.

And now the marten:

You can tell that the track size is much, much bigger compared to the length of the bound. These trails tend to be more steady, too, and it is common to see the tracks lead to a tree trunk and disappear as the marten goes up a tree searching for squirrels.

And a few pictures of both together:

Hopefully these are helpful.

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Grammar is addictive

I’ve been hearing the word “addicting” being used a lot in the last 3 years or so… and I’ve never thought it was really a word. Apparently I’m not the only one:
This site has a good explanation

It looks as though either works, although addictive is the more traditional favorite.

Now if we could let people know that “loose” and “lose” are very different words…

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