M56 Needs Some Friends

Imagine the plight of M56, the intrepid wolverine who made it to Colorado from northern Wyoming in 2009: alone, ranging through some of the most rugged territory in the Lower 48, wandering vast country in search of another of his kind, who most likely isn’t there. Wolverines were apparently wiped out of the Rockies, with the exception of isolated pockets of Montana and Idaho, by predator poisoning programs in the early 20th century, and when M56 dove off the edge of known wolverine habitat and struck out for the southern Rockies, he was recolonizing uncharted territory. Anecdotal reports of other Colorado wolverines exist, but as far as we know – scientifically speaking – M56 is the only gulo in the state. The nearest known breeding population is in the Tetons, which means M56 is adrift in an empty land. As Jason Wilmot said in a wolverine presentation in November, “If there’s a female wolverine in Colorado, he’s the one who’s going to find her.” The fact that M56 has not stuck in one territory, instead ranging throughout the Colorado Rockies, suggests he’s still looking. Poor guy.

But perhaps his quest will have a happier ending, thanks to a Colorado Division of Wildlife proposal to consider reintroduction of wolverines to the state. The proposal is still just that: an option to be considered, and not a definite plan. Some articles are quoting the proposed number of wolverines at 30 to 40, which would probably give M56 more companions than he could deal with. The earliest that the reintroduction would occur is 2012, and funding, among other details, has yet to be dealt with.

The inclusion of Colorado as wolverine range in the listing decision probably wasn’t coincidence; even without talk of a reintroduction, M56’s jaunt was attention-grabbing. Some people have suggested that female wolverines are incapable of making similar forays, but I asked Jeff Copeland about this back in November, and he said that it’s not necessarily true that female wolverines can’t make those epic excursions – it’s just that so far, they haven’t been documented doing so. Why? Female wolverines occupy the nearest vacant territory to their birthplace. They’re motivated to go only so far as they need to, until they find a territory that can support them and hopefully offer enough nutrition for reproduction. A male, on the other hand, will keep going until he finds a territory that encompasses a female’s, because life is going to be kind of pointless for him, in an evolutionary sense, if he doesn’t. The ratio of males to females is about 1:2; that is, a male tends to overlap with two females, so there’s a lot less room on the landscape for males. Hence, males have to go further.

Annie, a Teton wolverine who died in an accident. Another Teton female settled in the Wind River Range, a significant journey; her twin sister went back and forth between the Tetons and the Wyoming Range several times before a territory in the Tetons opened and she settled there. It's possible - though not certain - that a female wolverine could make it to Colorado even without a reintroduction.

But females do make impressive movements, which dim only in comparison to M56’s tremendous trek. To recolonize all of the US Northern Rockies, female wolverines have made some major journeys already, some of which we know about, some of which we can infer based on distance between occupied ranges. Females seem just as capable of continuing until they get to a good spot, and if the nearest good, vacant spot happens to be in Colorado, I wouldn’t be surprised if a female wolverine could make it. So put the talk of reintroduction aside, and you still have a distinct possibility of wolverines establishing a breeding population in Colorado on their own.

Still, that would leave a lot to chance, and the science, as summarized in the listing decision, highlights the risk of increasing temperatures and diminishing snowpack as a barrier to connectivity for wolverines in the Rockies. Year by year, wolverines of either sex will be required to disperse over greater distances in search of smaller patches of suitable habitat. Unfortunately, we still don’t have an assessment of the wolverine population in Wyoming – only the Tetons and Yellowstone National Park have been studied so far; the Tetons have a breeding population, Yellowstone has very few animals and no reproduction has been documented – so we don’t even know how many juveniles are potentially available to serve as a source population for a natural recolonization of Colorado. Coming to any conclusions about how and when a natural recovery might happen is difficult, and even if one or two females did make it, there would still be issues of genetic bottlenecks.

Reintroduction, proponents might argue, will give a boost to a natural process, and might stave off some of the effects of climate change by preemptively establishing a population node in a large chunk of suitable habitat. Significantly, according to local-scale climate models, the Colorado Rockies will retain spring snowpack in a hundred years, so the region could be critical to wolverine survival. Colorado hasn’t indicated a definite source population for the proposed reintroduction, but hypothetically, if they came from Canada or Alaska, which have the most robust wolverine populations in North America, the infusion of genetic diversity would be good for the overall Rockies population. (On the other hand, scientists estimate that a population node, in isolation and without connectivity to other nodes, would need 400 breeding pairs to maintain enough genetic diversity to survive. Colorado is not going to support 800 reproductive wolverines, so over the long term, unless there really is connectivity with Wyoming populations, we still have a problem.)

Scientifically, the reintroduction proposal is compelling. Endangered species, however, are among the most socially contentious topics in the Western US, and carnivores tend to raise the most heated passions on both sides of the debate. The on-going, wearying arguments about wolf and bear management are all the illustration one needs; no one wants to see wolverines disappear into the black hole of symbolic politics. M56 needs friends, but he needs human friends – or at least, people friendly to the reintroduction proposal – as much as he needs gulo friends. The ski industry and other individuals are already raising concerns about the impacts of a reintroduction.

Luckily for M56, we are dealing with an animal that is significantly different from wolves or bears, and the concerns that people might have can be addressed. But before we proceed with putting wolverines on the ground, or even advocating for the reintroduction, we owe it to M56 and wolverines throughout the Rockies to make sure that the social process is adequately carried out. The Colorado Division of Wildlife has been meeting with stakeholders to discuss concerns, as reported in the press, and so far, environmental advocates don’t seem inclined to make this into a rectitude-based battle of values. These are promising signs. If the reintroduction does go forward, I hope that it not only reestablishes wolverines in a crucial part of their historical range, but that it’s done in a way that can serve as a positive model of endangered species conservation in the West – something that’s as badly needed as  another thriving population node of wolverines.

Scents and Sensibility

In a talus field in the Altai mountains of Mongolia this summer, I entertained a bemused friend and a local herder by  crawling underneath every large boulder in a three kilometer radius to look for scat. The herder had informed me that this particular mountain was “the place where wolverines raise their families.” We rode three horses – mine was the ornery one, of course – precariously up the mountain and then, confronted with an infinity of scattered stone, I  went out of my head with some form of obsessive-compulsive disorder that compelled me to look everywhere that a female wolverine might have denned. The wind was blowing, the temperature hovered near freezing, and I felt like my ears and fingers were about to fall off. After several hours – the herder used the time to climb to the one spot in dozens of kilometers that had cell-phone reception, and called his girlfriend – I finally located a pile of dessicated scat. My friend snapped photos while I sat and stared at the pile of crap, an inner debate raging: pick it up, or leave it? Was it wolverine, or not?

There was no way to tell. At risk of grossing out my readers, I did pick it up (with gloves) and put it in my pocket (securely wrapped in paper and a plastic bag), and after several days I began to smell like a wolverine, although that may have had as much to do with hanging out among livestock and not showering for two weeks as it did to do with the specimen. Nevertheless, there was something peculiarly pungent about that scat. I was convinced that it was wolverine – what other carnivore would leave a pile of scat underneath a talus boulder? Still, my nose wasn’t truly good enough to tell.

Fortunately, there are creatures out there with better noses than humans’ and they are able to distinguish among scats. An interesting piece about conservation dogs appeared last week in the Los Angeles Times, mentioning wolverine work in the Blackfoot Valley of Montana. Working Dogs for Conservation trains dogs to find wildlife scat, with a much greater success rate than that enjoyed by biologists who try to do the same thing without canine aid. As the wildlife biology world moves towards non-invasive approaches to monitoring wildlife populations, techniques like this gain in importance, particularly for those species that are elusive and difficult to monitor using traditional means. The wolverine is certainly the emblem of “difficult” when it comes to research, and my dilemma on the mountain illustrates the potential usefulness of having a keen canine nose on your side. I’m not sure how well it might work, but it’s certainly an interesting idea, and I look forward to hearing more about whether this could provide a new tool for gulo research.

I’ve always been impressed and inspired by wolverine biologists, and I was glad that the commitment and tenacity of researchers came through in the recent PBS wolverine documentary. I occasionally enjoy gently mocking my wolverine folks – and myself – for what we’re willing to put ourselves through to study the species.  But I was disappointed to read a film review in the Miami Herald suggesting that we’re all “loopy” “goofy,” and “daffy” for our devotion to the species.  And I was particularly disappointed that the review perpetuated the idea that wolverines are ferocious and, as the author puts it, would “as soon eat [wolverine biologists’] eyeballs as look at them.” Wolverines are not dangerous to humans unless you back one into a corner and start poking at it with a stick – in which case, you could well be considered loopy. If you are fortunate enough to see a wolverine in the wild, and it comes running towards you, it’s not interested in attacking you – it’s probably interested in seeing what you are. Curiosity is a weasel trait, after all. Again, I wouldn’t try to pet one, and if one did start acting aggressive, I’d back off, but they’re not out to get you.

On that note, my sister and I were hiking in Grand Teton National Park two weeks ago when we heard a tremendous shrieking noise from up the hill. I climbed into the rocks to see if I could find the source of the noise. Suddenly, from beneath a boulder a few feet away, a short-tailed weasel in winter white shot out towards me. It stopped, looked at me, and then danced towards me, staring at me with cool ferocity – all 10 ounces of it poised against my 110 pounds – and then scampered off up the hill. Ten seconds later, another, smaller weasel emerged, glanced at me with that same unconcern, and tore off after the first weasel. The second weasel returned a minute later, gave me another look, and retreated under the boulder, but continued to gaze out at me. There is something decidedly disconcerting about a small animal that acts so counter-intuitively towards something 100 times its size. Perhaps that’s part of what makes weasels so enduring – the sheer unexpectedness of the approach helps keep them safe from predators who expect them to run away. But it also gives them an undeserved reputation for evil intentions and devilish possession. Those weasels, like their larger cousins, were just trying to figure out what a gigantic human was doing in their territory.  I’m lifting a quote from The Wolverine Foundation’s website to accompany this picture of the second weasel:

Short-tailed weasel, Grand Teton National Park, November 2010

“Picture a weasel — and most of us can do that, for we have met that little demon of destruction, that small atom of insensate courage, that symbol of slaughter, sleeplessness, and tireless, incredible activity — picture that scrap of demoniac fury, multiply that mite some fifty times, and you have the likeness of a Wolverine.”

Ernest Thompson Seton
“Lives of Game Animals”. 1925 – 1928. Vol. II

Walter, Jasper, and Banff

Gianna Savoie was kind enough to send me a few photos from the filming of Wolverine: Chasing the Phantom, providing a behind-the-scenes look at what it takes to make a documentary about Gulo gulo.  I’ll be posting some of these over the next two weeks, in the lead-in to the PBS premier on November 14th.

The film crew in wolverine weather - director of photography Joe Pontecorvo, writer and producer Gianna Savoie, and cameraman Kipjaz Savoie. Photo copyright Gianna Savoie

Jasper displaying some wolverine ferocity for the camera. Photo copyright Kipjaz Savoie.

In early October, I was up on the South Teton when I spotted two sets of tracks heading up a snowfield across the canyon from where I was sitting. They were far enough away that making a definite call was difficult, but at least one set seemed distinctly wolverine, a three-by turning into a scramble as the snowfield pitched steeply upwards. The other could have been gulo as well.

A few days later, a hiking party spooked a wolverine in the same area and caught it on video as it headed for safety. This is not the same snowfield on which I saw the tracks; it was one drainage to the north. Reportedly, the wolverine in this film scrambled up the snowfield and then dropped over into the canyon where I’d been hiking.

The hikers christened the wolverine Walter after one of their party, although we have no way of knowing whether it’s male or female. For those of you who are interested in honing your wolverine ID skills, the film offers a nice glimpse of how a wolverine looks and moves.



Goats and Glaciers

The second part of the narrative about F3 will be forthcoming, but in the meantime here are a couple of articles peripherally related to wolverine habitat and, possibly, diet.

Glacier National Park has lost two more of its namesake features, leaving it with just 25 glaciers, a paltry remnant of the 150 or so that were there when the park was formed . The remaining glaciers are predicted to melt within the next decade. Glacier Park is the heart of the Lower 48’s wolverine population; if the Rockies south of Glacier are considered an archipelago of high altitude islands between which wolverines must ‘swim’ to maintain a healthy population, Glacier itself is a mainland of sorts, with its own robust population that may (or may not?) send out dispersers to help maintain the population to the south. The Glacier wolverine study captured an animal, on average, every 11 trap nights. By comparison, the Absaroka-Beartooth Project has a capture rate of something like one animal every 45 traps nights (that number is not precise) with equivalent coverage of known occupied wolverine habitat. Wolverine home ranges are smaller in Glacier, perhaps indicating a greater concentration of food resources. On the whole, for a wolverine in the Lower 48, Glacier is probably the place to be. Given the links between successful wolverine denning and deep spring snowpack (Copeland et al, 2010), not to mention the role that the glaciers play in engineering a high altitude ecosystem, the loss of these features – or, more accurately, the climate trends that they illustrate – will have some implications for wolverines in what has been a stronghold of the population.

Mountain goats are another iconic species of Glacier National Park, but biologists don’t believe that these animals were present in the Greater Yellowstone region until they were introduced to parts of southern Montana by sportsmen in the 20th century. Reports that mountain goats are now making their way into Grand Teton National Park are presenting a problem for park managers, since the goats are invasive and may threaten the Tetons’ struggling bighorn sheep herd. On the other hand, who wants to be caught killing off cute, picturesque, and charismatic large ungulates in the name of cold-hearted scientific management? This kind of thing does not sit well with the public, even though it could be necessary to protect another population of cute, picturesque, and charismatic large ungulates.

Wolverines might be just as happy at the new arrivals as camera-wielding tourists, since mountain goats are an important food source in much of wolverine range. The Teton wolverines appear to be doing well even sans goats, but an influx of large, edible animals specially adapted to hang out on high craggy peaks where nothing else can comfortably live wouldn’t be a bad thing. Unless it interferes with the sheep, which wolverines might also be eating.

Wolverines can survive without mountain goats, so the presence of wolverines shouldn’t be taken as an argument against controlling the goats. But goats seem to be among gulo’s favored foods, so it’s simply an interesting ecological situation.

The Trickster’s History (F3 Capture, Part 1)

F3 has been trickster and holy grail; a young female just entering her reproductive years, an essentially elusive creature, and – by way of coincidence or by way of the chaos-inducing powers attributed to her species by cultures worldwide – a vortex around which comical and aggravating circumstances seem to swirl.

First captured and instrumented in 2007, F3’s original set of instruments failed, and the research team had to recapture and reinstrument her. In spring of 2008, she was captured again and we hoped to recollar her, but a blizzard swept in, the roads to the capture site were shut, and the field crew had to release her.

One of the cameramen for the PBS wolverine documentary accompanied us on a summer 2008 expedition to investigate GPS points obtained from F3’s 2007-2008 collar. He’d just returned from Pakistan, where he’d made a film on one of the world’s foremost mountaineers, and he had earlier served for ten years on search-and-rescue on Mt. Kenya while living in Africa. He was unable to complete the trek, stating that it was the most rigorous he’d experienced in his years of filmmaking.

On location for the wolverine documentary: an investigation of a GPS site yielded insight into what F3 was eating....

....mountain goat. We retrieved the jawbone from a ledge on a cliff, almost exactly on top of a set of points where F3 had spent several days over the course of late winter and early spring, 2008

On a second expedition that summer to investigate GPS points from F3’s collar, another accompanying participant developed blisters that were so bad she could hardly walk; we had to curtail that trip without reaching one of the sets of points we wanted to investigate. On that same trip I nearly fell off a cliff that I was scaling to try to get a view of a ridge along which F3 seemed to travel regularly.

One of F3's travel routes through her territory

Perhaps part of the point is an acknowledgment of the fact that 100+ pound bipeds should not attempt to act like 20-30 pound wolverines, because we are simply not designed to cover the same terrain in the same way. But the difficulties assumed a more superstitious import, as if this particular animal was one step ahead of us and laughing over her shoulder as she led us on. Last year she was photographed by the automatic cameras at the research traps on several occasions; we know that she ventured into the traps, but never actually pulled the trigger. Then, as now, we were eager to know whether she was denning, but later telemetry flights caught her ranging over 25 or 30 miles in the course of three days, indicating that she wasn’t tending babies. This year, the field crew trapped her in early March, but since we knew that M57 had been in her territory since the summer breeding period and we thought she might have kits, they let her go. Telemetry flights over the next few days showed that she was, again, all over the place.

First thing on Thursday morning, I got a call from the director of the field crew, letting me know that there were tracks circling the traps and that we should have the field kit ready to go. We were cutting things close; once the bears come out, we shut the traps, and boar grizzlies had already been sighted on the move in Yellowstone and Grand Teton. At best, we had 48 hours before we would have to close the research operation for the year. It would be in keeping with F3’s habits to circle the traps repeatedly a day or two before the end of the season, taunting us with the prospect of a capture, but never actually allowing us to collar her.

We had a collar on M57, which meant that we would be gaining all-important fine-scale data about how he was using the landscape. But understanding how females use their territory is important to determining what drives reproduction, and at this point, understanding reproduction is one of the most pressing research questions for wolverines in the Lower 48. Collaring F3 might allow us to gather some data on this question. When I left the office at 5:00 that afternoon, there was still no word.

At 8:30, my phone beeped and I pounced: a text message that F3 was in the trap. We were headed to Montana.


On Saturday I went skiing in Death Canyon, and on the way down, took a detour to follow some interesting tracks. They caught my attention for a couple of reasons; the distinct and very regular 2x gait, and the trough through the snow.

The regular 2x gait and the trough around the prints prompted me to follow the tracks

They were clearly made by a medium-sized animal moving determinedly across the landscape. There aren’t that many candidates for tracks like these. They appeared too big to be marten, although in places the stride seemed short for a wolverine. I followed the tracks for about a mile; the animal would move rapidly across open spaces, and then duck under a grove of trees, look around, occasionally put its paws onto the snowy bark of a pine and, presumably, look up to see if there was anything to eat, before returning fairly quickly to its original course to the north, hauling across open meadow towards the next grove.  To the sides of the prints, on the edges of the trough, the drag marks of long fur were occasionally visible. On close examination, I could see claw marks at the front of the tracks, and in a few places, where I crawled under the trees to examine the tracks against harder snow, I could see imprints of widespread toes and, once, the impression of what appeared to be a chevron-shaped interdigital pad. Canid tracks have a distinct triangular shape, and if it had been a cat, the claw marks probably wouldn’t be visible. Odds were good that I was tracking a weasel.

Impressions of clawmarks and a widespread print indicate that this is not a canid or felid

I was at about 7100 feet, which seemed low for a wolverine, but not impossible, especially given the abundance of game at this elevation; squirrel and hare tracks were visible near the trees, and moose wandered the slopes. The 2x tracks eventually went straight up a steep, downfall-tangled hill; I followed them upslope just long enough to collect what I had been sure would show up eventually: scat. The scat was small too, but I tucked it into a folded square of paper and then headed back.

When I showed the photos to Jason on Monday, he ranked the tracks “probable” – too big for marten, all wrong for wolf. The only other possibility was an otter; the tracks weren’t far from Phelps Lake and Jason said that he’s seen otter tracks across high mountain passes miles away from water. But he also said that otters tend to place their feet directly beside each other, rather than offset in the way these tracks were. Hopefully we can send the scat to the lab and that might provide a more definitive answer. In the meantime, though, it was a good way to spend a Saturday in the Tetons.

Another single print - look closely, and the interdigital pad is almost visible

Tracks in the Tetons - to the left are the probable wolverine tracks, to the right those of Homo sapiens skierensis