Territories, sociality, calories, and kin: When do wolverines party together and when do they party on their own?

Last week I offered some considerations to take into account when assessing a wolverine sighting report. Since the specific sighting report under discussion involves an alleged gathering of 12 or 13 wolverines, I’m going to review what we know about wolverine social behavior, and discuss previous circumstances under which we’ve seen more than two wolverines in one place.

Both male and female wolverines are territorial. This means that adults exclude other adults of the same sex from their own territories. They patrol the boundaries of their territories, and scent mark to keep other same sex adults away. Territories tend to be pretty large, although they probably vary in size with food availability. The boundaries appear to be pretty inflexible – collar data from the landmark study in Glacier National Park shows very little overlap between two adult females with contiguous territories. There is data from a scat and track survey in Sweden that does show some apparent flexibility in some territorial boundaries for adult females, particularly during denning season, when the boundaries regularly patrolled by the female shrink. But there has been no study to date that has shown social behavior among unrelated adult wolverines of the same sex.

Later in the year, after the kits have left the den, camera traps regularly pick up adults traveling with kits. If a female had four kits, that would account for up to five wolverines together. If the male joined them, six wolverines might be traveling together. This is probably the maximum family size, and would be pretty unusual to see. Female wolverines have a system of delayed implantation for fertilized eggs, and they only become pregnant if they have adequate body condition to carry the pregnancy and nurse the kits. A pregnancy with four kits would require a very healthy wolverine, and since lactation is more costly to fitness even than pregnancy, successfully nursing four kits would be a pretty big feat. Typically we see two kits every other year; even seeing three kits is significant and not terribly common. These sorts of numbers indicate a very robust set of food resources. There’s a relatively high rate of kit mortality within the first year, too.

Kits typically remain in their parents’ territories for up to 18 months before dispersing to establish their own territories. We don’t know exactly what is going on during this time, but we do know that the kits appear to spend time alternately with their mother, their father, and their siblings, as well as exploring on their own. This kind of extended care in mammals is relatively rare and if I had several million dollars and more time, this is probably what I’d study. Regardless, we do know that there might be up to six wolverines sharing a territory at once – territorial female, territorial male, and, at most, four kits.

There is also occasionally the potential for overlap of kits of one adult female into the territory of another adult female who is not the mother; this happens if the two adult females are sharing their territories with a single male. The kits may travel in the portion of their father’s territory that overlaps with the adult female who is not the mother, but at least in the collar data I’ve seen, they don’t venture into any part of that adult female’s territory that is not also part of the father’s territory. So if you imagine the four kits of one female traveling into the territory of another female, and running into that female and her four kits, and then the male who is the father of both litters being around at the same time, you might have the potential for ten wolverines in one spot, without violating the rules of territoriality as we currently understand them.

Would this be a particularly tranquil gathering? I doubt it. But is it possible? Yes. Especially if there were a very abundant source of food nearby.

An abundant food source is in fact the one thing that will draw in larger numbers of wolverines. The most notable, and only naturally occurring, instance of this that I’m aware of was in 2008 in Kamchatka, Russia, when photographer Igor Shpilenok found a dead bear and photographed the scavengers who showed up. He documented six wolverines on this carcass – again, that number is within the limits of a kin group. (Google translate is now good enough to use on these pages with coherent results, but I also did a summary of these materials a few years ago with the invaluable help of my Russian-speaking friend Marissa Smith.) Some of the body language in these photos looks less than friendly, and Shpilenok relates stories of them fighting, so maybe they weren’t related. A carcass close to the border of a territory would be enough to lure an unrelated wolverine over, especially if it were hungry enough.

The other famous (in wolverine circles) instance of multiple wolverines on a food source comes from a video taken at a dump at a mine in Chukotka, in northern Siberia. In this video – watch it with the sound on, the music adds a particular flair – twenty-five or thirty wolverines scatter from a dump as a truck drives up. I thought this video was fake the first time I saw it, it simply seemed so unreal. But there were other videos around social media, posted by the miners, of workers feeding wolverines and foxes sausages and other foods from the mine cafeteria, as well as wolverines hanging out at night while heavy equipment was being operated. These are obviously highly food-conditioned animals and there is an abundant supply of calories; effectively, the availability of food is so great at sites like this that it removes the animal’s need to defend a territory to stay fed. This is true also of captive wolverines, who can live together in shared space fairly harmoniously as long as there’s enough food.

Which brings us to the hypotheticals – if there really were a dozen or so wolverines up at that site in the Teton Wilderness, what were they doing there and why were they tolerating each other? Food is the obvious answer, and of the potential food sources, moths are the most interesting possibility. Grizzly bears are known to feed on army cutworm moths at high elevation talus sites between July and September, and the August 8th date would be squarely within this range. Army cutworm moths contain more fat for their weight than butter, and large numbers of bears often gather at these sites to put on pounds. At least in Glacier, there’s some speculation that the females take their cubs up high not only for the food, but also to avoid adult males, who tend to stay lower and who are, of course, a danger to cubs. The mothing behavior of bears is much better known in Glacier than it is in the greater Yellowstone ecosystem, but there are current studies looking at sites in the GYE.

We’ve often wondered whether wolverines might also take advantage of army cutworm moths as a food source. It’s never been documented before, but wolverines are opportunistic and in a good moth year they could certainly be feeding up there.

Other insects also migrate over or congregate on snowfields; I’ve seen feeding frenzies of birds on snowfields during butterfly migrations. And there’s always a possibility that there was an ungulate carcass or even several carcasses that had melted out of the snow up there. So there are other possibilities for a food source that might have drawn animals in. Particularly if this location is at the intersection of a number of wolverine territories, it’s possible that adequate food could serve as a flag of truce for a larger number of wolverines. Incidentally, bears on moth sites also tend to be comparatively peaceful and far more interested in the food source than in anything else, including other bears, so it’s also possible that they wouldn’t be bothered by a bunch of other animals being there at the same time.

The other, more remote possibility is some kind of cooling behavior. Summer in this ecosystem was sweltering this year; a friend and I went backpacking in early September and it was about 80 F at 10,000 feet, and much hotter lower down. It was the most unbearable outdoor experience I’ve ever had; if there had been any snowfields in the vicinity, I would have lain down on one and not moved, even if there had been four grizzlies and 13 wolverines on the snowfield with me. Wolverines have a pretty temperature-constrained global distribution and they don’t seem to tolerate anything over 70 F very well. Maybe if it gets hot enough, a cool location might also be a coveted enough resource to break down territorial barriers. It would be interesting to know what the temperature was at the sighting location on August 8th.

Those are my best guesses at what might have been going on at this site if all of those animals actually were wolverines. Again, I’m not offering any kind of final verdict at the moment. But I am underlining again that large numbers of female bears with young cubs are known to gather at high elevation mothing sites in both Glacier and the GYE. Grizzlies also hang out on snowfields to cool off and sometimes just to play. And from a long distance, and in blurry photos, bears and wolverines share similar profiles, postures, and gaits. Again, things like this could have been sorted out with an immediate site visit, so it’s too bad that it took such a long time to report the sighting.

(And yes, the title of this post is an affectionate parody of the titles of various ethnographies that I’ve enjoyed recently – not meant to be taken seriously or to imply that wolverines actually party.)

Herds of Wolverines?

There’s a story circulating about a sighting of “12 or 13 wolverines” allegedly “chasing grizzlies” off a snowfield in the Teton Wilderness in Wyoming in August of 2022. The report comes from a tour company that had a verified wolverine sighting in Yellowstone National Park in March 2022; the August sighting report was posted in some detail, along with photos, on the company’s facebook page on October 2nd.

Without weighing in on whether I think this is an accurate report, I do want to use this opportunity to talk about what happens when a sighting report comes in, and remind folks what to do if you think you’ve seen a wolverine – and this goes double if you think you’ve seen all the wolverines in the Greater Yellowstone Ecosystem having their first post-pandemic in-person wolverine conference on the slopes of a wilderness mountain.

First off, documentation is key. The several participants in the hike took photos, from a distance, of a number of animals scattering across the snowfields. This is great. But as we often lament in these situations, photos of putative wolverines at a distance are generally of poor quality and are frequently inconclusive. When assessing a sighting report – and this, by the way, is just my own personal process; other biologists may have a different approach – I always ask if there’s anything else that this animal could possibly be, based on the reported behavior, habitat, and evidence provided. If the answer is “yes,” then I cannot conclude that it’s a wolverine. I can conclude that it might be a wolverine, but not that it is a wolverine.

In this instance, because the photos were taken from such a distance, it would have been best if, safety considerations permitting, the hikers had gone to the snowfield to document tracks and look for scat or hair. There are all kinds of reasons why this might not have been feasible, and that’s fine, but again – the evidence that is presented makes it difficult to conclude that these were definitely wolverines.

The terrain, the desire to reach their hiking goal, or the risk of running into a grizzly could all have prevented the hikers from making a closer examination of the site itself. This is why timely reporting to the nearest responsible management agencies is key – especially in the absence of conclusive evidence. This sighting took place on August 8th, but was first publicized in a social media post on October 2nd. The post was written by someone who was not present at the actual sighting, although it did include descriptions written by one of the hikers. As far as I know, there was no report to either the Forest Service or Wyoming Game and Fish in the immediate aftermath of the sighting. This is too bad, because either of those agencies would probably have the resources – and the motivation – to go in to the site and investigate such a significant report. It was also not reported at the time to non-profits like the Wolverine Foundation which, in the event of a sighting this interesting, would also have had an incentive to immediately visit the site. The hikers said that they were concerned about “a rush of tourists” to the site, and that kind of caution is important. But the individuals who would have visited from these organizations would have been few in number and have spent a lot of time thinking about and practicing non-invasive methods of wildlife assessment.

Finally, there’s the issue of ethical communication – and this bit is directed primarily to the media. We all know by now that we live in an age of out-of-control information, and that even things shared with the best of intentions can end up going feral and contributing to inaccurate perceptions of a situation. In this case, the social media post was picked up by media outlets, and reported on as a verified sighting that took descriptions of the putative wolverines’ behavior at face value – both in terms of congregating in large groups, and “chasing” grizzlies. It’s worth noting that the original post did not exactly state that the wolverines were “chasing” the bears, but much of the press used the most sensationalized headline possible.

Don’t use headlines like this (accessed October 12 2022 from Field and Stream website)

The media should have verified events with the hikers who were present at the sighting, to make sure that the hikers’ perceptions were in alignment with the description. Reporters should have reached out to biologists for comment, too. It’s especially incumbent on media outlets to do this when there are issues around public perceptions of an animal’s behavior and numbers. Comments on the tour company’s facebook post expressed both fear of the alleged aggressive behavior, and also relief and confidence that the population was, in the words of one commenter, “thriving.” These commenters are people who already have some interest in wildlife and this ecosystem; when stories like this end up in national news, the audience is less well educated on the topic and even more prone to misperception.

These sorts of impressions tend to stick with the public and pop up in discourse later on. It isn’t helpful to have people worrying about being attacked by packs of aggressive wolverines. I say this as the person who, at multiple public lectures and in private conversations each year, has to field questions about whether people should be worried about dangerous wolverines coming after them.

And unverified claims that three or four females are having three or four kits apiece in an area this small can start to permeate public perceptions of the status of the population, and potentially undermine conservation actions when, for example, the public is invited to comment on listing proposals or other management efforts. In a worst-case scenario, reports like this could serve as justification to advocate to reopen the trapping season in Montana, up the trapping limits, and/or pursue more aggressive development and recreation within wolverine habitat. If there truly are this many females with this level of reproductive success, then managers could in fact make persuasive arguments for any and all of those actions. If there’s any sort of error in the report, but people assume it’s true and argue for management actions on that basis, a tenuous population is dealt a pretty big blow. This is why evidence and verification are essential in these situations, and responsible journalistic standards are critical.

Again, none of this is to issue any kind of ruling on the sighting itself. But the way it was reported in the press has thus far been irresponsible, and I hope to see better reporting forthcoming. The best article on this event to date is in the Cowboy Daily, whose reporters did contact state wildlife officials for comment and provided background on wolverine behavior and population status in the state. Kudos to the local news operations with the local contacts and the local expertise. This is the approach we like to see.

Finally, a word about credibility. Friends have asked me whether I think this is a credible report. A lot of people making wolverine sighting reports want consideration for their own expertise and emphasize their outdoor skills and wildlife experience, and the individuals who made this report do have a lot of outdoor background. But assessing a report is never about the credibility of the individual – it’s about the credibility of the evidence. The most expert outdoorspeople I’ve dealt with know this and when they make reports, they present the information, present the evidence, offer their interpretation, and then we discuss it. The evidence is the key. If it’s conclusively a wolverine or conclusively something else, we have an answer. A conclusive yes requires clearly identifiable and geographically locatable visuals, DNA evidence, and/or a carcass (in the case of roadkill, for example). With anything less definite, in the absence of a site visit, we can only say what it might have been, regardless of how much experience the individual has with wildlife.

This standard may seem harsh, and ego can flare up pretty quickly in these situations, but there are good reasons for focusing on the evidence and not the individual making the report. A very basic one: we’ve had people who have a fair amount of expertise make intentionally false reports in the past. Those sorts of experiences highlight the necessity of starting at neutral with every report.

A more scientific reason for assessing evidence over expertise: if we enter the report and the evidence into some kind of database and someone is looking at it in a few decades or centuries to assess, say, historical reports of wolverine sightings, they may have no access to the individual who made the report, and no way to know anything about the person’s wildlife knowledge. This is why the evidence itself has to stand on its own as conclusive if we are going to count a sighting as verified. Someone else, someone we never have a chance to speak to, many years down the line, should also be able to look at that evidence and say yes, this truly was a wolverine.

I think often about Thoreau’s alleged sighting of a wolverine in Maine in the 1850s. He has a lot of credibility as an individual concerned with the outdoors, but because Maine would have been marginal wolverine habitat, because the word wolverine was sometimes used to refer to lynx at that time in New England, and because there is no evidence beyond his claim, we don’t know what he actually saw. And we never will.

And on a more personal note, I know I’ve made initial mistakes in ID in the field, due to exhaustion, brevity of sighting, or wishful thinking. I once spent 15 minutes pretty convinced that a small animal scaling a cliff face across from my remote campsite in Glacier National Park was a wolverine, until the friend who had been using my binoculars to watch some kestrels returned and I got a closer look and realized it was a marmot. We’d had a big day, I was tired, I really wanted to see a wolverine in Glacier, and I wanted my friend to see one too. I also hadn’t realized that marmots were such adept cliff-climbers, or that they could look so sinuous going up rock faces. I later went up the cliff and found the marmot scat, just to be absolutely certain. Stuff like this happens. We laughed about it. I have an increased respect for marmots as rock-climbers. And since neither I nor my friend have yet seen a wolverine in Glacier, we have an excuse to go back and keep looking.

That’s the run down on what happens in wolverine sighting report assessments – even my own. And again, this is just my own process. I know that wildlife sightings can happen quickly and that sometimes getting reliable evidence isn’t easy. There are some reports that are destined to remain uncertain, but even those are useful and interesting. To the greatest extent possible, though, document the evidence, report it quickly, and think carefully about how you communicate about the sighting.

I will post something on here separately about previous verified records of larger gatherings of wolverines, what we know about social behavior in wolverines, and what causes wolverines to congregate. I may also offer a bit of analysis of the information and images in that facebook post. Meanwhile, here’s a guide to documenting wolverine sign – always a good thing to review as we head into the winter ski season and tracks become much easier to find.

Return of the Wolverines (and the blog)

It’s been a pretty big week for wolverine sightings in the US Rockies. A wolverine was spotted in Yellowstone National Park last week, and another in Lewistown, Montana a few days ago. These are both considered rare occurrences, although it’s worth thinking about why they’re considered rare.

In Yellowstone, there’s a long record of wildlife sightings that includes very few wolverines, despite the fact that the park fits certain habitat parameters and hosts an abundance of ungulates that could serve as prey and/or carrion. Yellowstone is high in elevation, cold, and surrounded on three sides by ranges known to at least periodically host reproductive wolverines (the Absarokas to the north, the Gallatins and Madisons to the north and west, and the Tetons and parts of the Absaroka range to the south). But the Absaroka-Beartooth Project, a five year study that ended in 2009, documented very few wolverines in the park itself or in the rugged mountains to the east of the park. Wolverines collared by the WCS wolverine study in the early 2000s were recorded crossing the park from ranges in the west to the ranges south-east of the park, but no one found wolverines living inside the park or using it heavily. This correlated with the dearth of sightings by tourists and rangers.

Of course, most tourists in Yellowstone stay on the roads, and most wolverines probably do not, especially in the summer when the tourists are most abundant, so there’s a potential disconnect between the habitat use of observers and the species of interest. Sure enough, this most recent sighting was on a road. So there is likely some bias in the wildlife sighting data.

But collar and research data – admittedly somewhat out of date at this point – also suggest that wolverines are just not inside the park in even the low-density numbers typical of wolverines. So are they selecting against Yellowstone, or is something else going on?

It’s worth remembering here that wolverines were extirpated from the US Rockies in the early 20th century and have been re-inhabiting former range since then. So Yellowstone may not be a bad place for wolverines, but it may be less desirable than surrounding mountains for various reasons – the high densities of competitors such as wolves and bears, the seasonally high density of people, the comparatively flat landscape that allows for less escape cover, or other factors that might make it more marginal. As long as the overall wolverine population remains low, wolverines will likely be less frequent in these livable but marginal habitats. As the population grows and becomes more dense on the landscape, wolverines are likely to travel through or even set up house in some of these regions.

Yellowstone may not even actually be that marginal – it might be great for wolverines. But Montana maintained a trapping season until a decade ago, which regularly took both dispersing juveniles and resident adults off the landscape and left holes in occupied habitat. So there simply may not have been enough wolverines to occupy Yellowstone; juveniles may have filled in the empty territories of trapped adults without dispersing further. With the closure of the Montana trapping season, more wolverines seem to be showing up in more places, many of them fairly far-flung. Correlation is not causation, but if we really want a fully connected and robust wolverine population with a chance of surviving the coming climate change onslaught, keeping the trapping season closed is, I hypothesize, a good idea.

As for the Lewistown wolverine, that sighting is considered rare because the animal was spotted in a place that is not wolverine habitat even in the absence of human occupation. The sighting seems especially strange to a lot of people because it was in town. But for all their reputation as emblems of wilderness, wolverines are seen in proximity to human settlements fairly regularly further to the north, where the populations are more evenly spread across the landscape and where attractants like garbage, pets, or interesting noises and smells might catch the interest of an exploring juvenile. In both Canada and Russia, wolverines show up in towns or at mine sites with regularity, if not with great frequency. The Lewistown animal was likely a younger wolverine looking for a new territory and bouncing among mountain ranges as it tried to figure out where to go.

Regardless, the excitement of people about these sightings was energizing to watch. It’s a good reminder of how wildlife can play an important role in creating connections between individuals and nature, as well as among individuals who share an interest.

A third video was made and shared last week by the crew at Swan Valley Connections, who have monitored wolverines and other rare carnivores for years. This sighting is less surprising from a habitat perspective – there are (again, comparatively) a lot of wolverines in this part of Montana – but it’s still a rare and exciting occurrence for a field crew to actually see a wolverine.

It’s been a big week for wolverine sightings in this part of the world. I was also pleased to manage to get some info about Mongolian wolverines into a CNN article about the Yellowstone sighting. This may seem like a minor thing, or even vaguely boastful, but when you’ve worked for 14 years to develop a project, with almost no help, no money, and no support from anyone, it feels like a small victory to see those two words – “Mongolia” and “wolverine” – together in a major news source.

Speaking of rare occurrences and appearances….this is the first post over here in over two years. I have a forthcoming post about why, about what a return to writing about wolverines looks like, and about what happens when labors of love become entangled with systemic problems and failures like bullying, exploitative behavior, and various forms of societal collapse. Fun times for all! The good news is that there will be an opt-out for people who still just want to hear about wolverines, because I’m really not interested in traumatizing anyone whose innocence is valuable to their peace of mind.

Finally, a big thanks to everyone who got in touch with me about these various sightings. That was another sign that wolverine enthusiasm remains high, and it was great to be in discussion with everyone who sent article or video links or just messages. You all are great.

Anyway, happy Week of the Wolverines, and stay tuned.

Sugar or a One-Eyed Horse

On the far western edge of Mongolia, in the Altai Mountains of Bayan Olgii aimag, a national park nudges the border with China. This place is called Chigertei (Чигэртэй), although it is sometimes spelled Chikhertei (Чихэртэй), which is how I read and wrote it for the few months between first hearing about it and actually setting foot there. The g-versus-kh debate is a reminder of the region’s unique cultural dynamics; the majority of Bayan Olgii’s population is ethnically Kazakh, descendants of a small number of refugees who settled in Mongolia during various 18th and 19th century conflicts with the Russians and Chinese. In 1940, the socialist government of Mongolia formed Bayan Olgii as a Kazakh aimag, creating a place where Kazakhs were allowed to maintain traditions that were more harshly curtailed in Kazakhstan itself, which was then part of the Soviet Union. Following the advent of democracy in 1990 and the opening of Mongolia to the wider world, some of these traditions became world renowned. Eagle hunting and the richly embroidered Kazakh ger hangings made for weddings are synonymous with the region. Although all official business in the aimag is conducted in Mongolian, school is taught in Kazakh, Kazakh remains the language of everyday interactions, and many families in more remote regions don’t speak much Mongolian at all. Bayan Olgii is a region where Mongolian and Kazakh run up against each other, culturally and linguistically, in interesting ways.

This is the source of the Chigertei/Chixertei mashup. Chixer means “sugar” in Mongolian, and Chixertei, roughly translated, means “sugared,” which, as a Mongolian speaker, I took to be a poetic reference to the snow that girds the Altai peaks for most of the year. Chigertei, on the other hand, means “a one-eyed two year old horse” in Kazakh. A long time ago, my Kazakh counterpart from the park administration told me as we jolted along the road to the park, there was a one-eyed two year old horse that hung out in the valley, and that’s how the place got its name. Why do Kazakhs have a specific word for a one-eyed two year old horse? Are there a lot of one-eyed horses running around Kazakh-populated areas? Is there a different word for a one-eyed three year old horse? Mongolian is like this in its precision – there are verbs to describe a calf running around with its tail in the air, or the act of tying ribbons in a horse’s mane to designate it sacred. There are dozens of words to describe the colors of a horse’s coat, and a whole herd of words to describe yak-cattle hybrids depending on the generation of hybridity. There are several words for “friend,” some of which indicate a greater degree of affection and closeness than others. There are a whole set of verb tenses that you employ to indicate how recently something happened, and how certain you are that it actually happened if you didn’t witness it with your own two eyes. But with Kazakh, I had no idea where things get specific, because the sum total of my Kazakh skills could be summed up in the two most essential phrases in any language: “Thank you” (Rakhmet) and “Are there any wolverines around here?” (Kunnu bar ma?) The exchange on the road to Chigertei served as a reminder that I was on strange ground. I’ve worked in Mongolia for 17 years and I’m used to being agile and fluent, culturally and linguistically. It felt both off-balance and also exciting to be in a place where I didn’t know what was going on 100% of the time.

Whatever direction you take the name, Chigertei appears to be full of wolverines, and that was why I was there. In May, a colleague who had set up cameras for snow leopards in Chigertei contacted me to tell me that he had gotten dozens of photos of wolverines, and would I be interested in collaborating on a project? I’d been to the Altai before as part of my wolverine quest, most recently in 2011, to interview and collect pelt samples. I’d wanted to work there on a more extensive and systematic program, but hadn’t had the time to do the most laborious preparatory task for any wildlife work in Mongolia – setting up relationships with the various authorities and finding local counterparts who were interested in collaborating. Barry Rosenbaum, the wildlife biologist who had put up the snow leopard cameras, had already done that work, so it was easy to agree. Easier still because snow leopards were my first wildlife love, the animal that had led me to the high mountainous landscapes that wolverines inhabit. Barry would be collaring in Chigertei’s sister park, Khokh Serkh, which meant that I might, if I were very lucky, have the opportunity to see an animal that held enormous personal significance.

Luck seemed to be in short supply for the first ten days after we set snow leopard snares in Khokh Serkh (the name, definitively Mongolian, means “dark blue billy goat” and refers to both the Special Protected Area and the mountain range encompassed by the SPA). The plan was to spend the first ten days of the trip collaring snow leopards, and then a week in Chigertei, 40 kilometers to the west, setting up baited wolverine camera stations. After a frigid first two days in the Khokh Serkh base camp, the weather warmed, and the Mongolians and Kazakhs insisted that the snow leopards would stay up high and away from our snares, snoozing in the sun, until the weather changed again.

Whatever the cause, the snares remained empty. The cameras we’d set up nearby yielded beautiful photos of ibex, quail, and ermine, but no sign of big cats. I was happy to be out on a snow leopard expedition, but it was mostly waiting, interspersed with the daily anticipation and letdown of heading up to the higher valleys to check the snares. The time between was spent rambling around the mountains, but there was something edgy and almost spooky about the steep, narrow, rocky valleys, dark in the scant light of the failing year. On one of our daily excursions to check the snares, my horse’s cinch strap slid back, the horse panicked, and I was thrown, dragged through a boulder field on a steep slope, and kicked twice. The damage was relatively superficial – bone bruises, a torn ligament or some other trauma in my right wrist, the most shockingly purple hoof-shaped bruise on my left buttock – but I couldn’t hike for a while afterwards, or sit on a horse, which meant several long days sitting in camp trying to figure out how to do anything useful when my only functional limb was my left arm. I was more than ready to get out of Khokh Serkh by the time we piled into the range rover and headed to Chigertei.

The land of sugar and one eyed horses was enchanting by comparison, a wide open swath of valley flanked by dramatic high peaks, the weather moving fitfully and spectacularly across the mountains and the river and the moraines left behind by recent glaciers, and wolverine tracks everywhere.

The high peaks on the western border of Chigertei Valley.

We stayed with one of the few families that winters in the valley – there are many more in the summer. The family were relatives of Yelik, our liaison at the park. His forebears had lived in Chigertei Valley for generations, he said, and pointed to a crumbling cemetery that we passed on the drive in, and said, “My family are all there. Two hundred years.” His cousin Yerlan, her husband Jaksalak, and their daughter Raya were our generous hosts, giving us space in their adobe house, renting horses to us, and regaling me with tales of wolverine sightings up and down the valley. For the first time ever in eight years of wolverine work in Mongolia, I heard stories of regular wolverine depredation on small livestock. Jaksalak told me, through translation into Mongolian by our ranger Aska, that he’d seen five wolverines together in the early summer, that he’d spooked them out of a thin line of forest that ran east-west along the north-facing slopes of the valley, and that they’d fled up into one of the big bowls above treeline. Five wolverines together could only be a family, and if it was a female and her kits-of-the-year, that meant she’d successfully nursed a litter of four. When I asked where they habitually saw wolverines, Jaksalak and two fellow herders waved their hands across the valley: everywhere.

Adobe and stonework home in Chigertei

It was pointless to speculate based on unverified stories, of course, but the herders of Mongolia know their wildlife well – far better than the Americans who report wolverines in their backyards and then send me photos of porcupines or foxes – so I was inclined to believe them. The photos from the snow leopard cameras showed at least two individuals visiting the same camera station within days of each other, and returning repeatedly.  It was all very tantalizing. But we’d learn more only by doing some scientific documentation.

The first day out, back in the saddle for the first time since being thrown off, I had a hard time focusing on where I was, too busy clutching the reins and trying hard not to think about the horse slipping on the ice, kicking me, dragging me across boulder fields, snapping my neck. Then we came up over a massive moraine and stopped at a boulder covered in petroglyphs, and all the crowding fearful thoughts disappeared as we dismounted and looked at the animal figures chipped from stone ages ago. Aska opined that the figures were little wolverines; I thought they were ibex. They were probably from the Bronze Age, which, in Mongolia, extended from about 2000-1000 BCE. There are petroglyphs like this all over the country – very ancient ones showing woolly rhinoceros and ostriches and mammoths, more recent scenes of men in chariots and reindeer with the beaks of birds. Out of all of this vast, Pleistocene world, the wolverine remains like a talisman of a lost past.

Petroglyphs. Depending on which end you see as the head, you can imagine these as running ibex with curved horns, or open-mouthed, stripe-tailed carnivores.

We rode further up the moraine and came out into a side valley, walled in at its head by another jagged range of peaks. From here we went on foot up the valley, and then up an east-facing slope, walking carefully among the snow-covered large-boulder talus. Before long we crossed wolf tracks, and then, inevitably, the prints of a wolverine. They led up through the talus field onto the ridge, where they and the wolf tracks joined a well-worn game trail running along the crest of the slope.

Dukhai and Aska on the wolf and wolverine highway

We set up four cameras in that valley, all of them along the east-facing slope. The west-facing slope was sheer scree and bare of snow, steeper and higher, far less appealing as a travel route. Aska and Dukhai, another of the winter herders, guided the effort, choosing spots where they’ve seen wolverine tracks in the past.

That night the wind rose until it howled around the outside of the house. Inside, Aska practiced his English by reading aloud from the back issues of the New Yorker that I bring with me on these trips; his pronunciation was flawless, and after a a sentence or two he would tell me, in Mongolian, what he understood, and then I would explain where he’d understood correctly and where he’d gone wrong. Since it was the New Yorker, this necessitated trying to explain phrases like “pathologically incompetent president” and “hipster locovore Brooklynites,” which was both headache-inducing and also a welcome challenge to improve my Mongolian skills. Neither Yerlan nor Jaksalak spoke Mongolian, although Yerlan liked to order me to eat more of the various dishes she cooked, thus improving my Kazakh vocabulary by about 1000% in the space of 24 hours. At some point, I explained to Aska in Mongolian that the wolverine’s Latin name meant “glutton” and that it had a reputation for eating enormous amounts of meat; Yelik, overhearing this, explained to Yerlan and Jaksalak in Kazakh; and everyone began saying “Gulo gulo!” before digging in to whatever dish Yerlan put on the table in front of us. Most of the time this was besbaramak, the signature Kazakh dish, which involves most of a sheep or goat, boiled for several hours, and served with enormous flat noodles, boiled carrots and potatoes, and sometimes a side of horse sausage. Invoking the wolverine came shortly after we washed our hands and bowed our heads and lifted our palms up for a quick blessing on the food from Allah. Sometimes I ended up translating whatever I understood back into English for Barry, although I’m terrible at remembering to do this, because translation is a task that requires focus. Later that evening, Aska and I digressed from New Yorker-level topics into our mutual enjoyment of the show Vikings, discussed which characters we most liked, and chatted about Norse history and Kazakh history. There was more comfortably cosmopolitan code-switching going on in the confines of that little adobe house, under the howling wind in the remote Altai, than in any place I’ve been in a while.

The wind went right on howling, and when we got up the next morning, a blizzard was beating down on Chigertei. Aska and Yelik swore it wasn’t as bad as the snowstorm that had hit the valley a few weeks before, so with that in mind, we all put on our warmest clothes and rode out.

Parking the horses in the blizzard.

It could have been worse. It could have been a few degrees colder, the wind might have had an even sharper edge, the snow could have been thicker, the visibility even more curtailed. As it was, I could see the dim outlines of the near mountains, if I squinted into the wind and snow, and I could remind myself that I’d been far colder and more uncomfortable, once or twice, on the ski transect of the Darhad that I’d done back in 2013. It was tolerable, in other words, in the minimal sense of the word. We were riding further out that day than we had the day before, but over less tricky terrain. The conditions did not make the horse any less nerve wracking, and Yelik and I had a moment of mutual vocabulary-building when I explained that I was nervous about galloping the horse in icy and snowy conditions. “Nervous” was new to him, and I realized with shock that I’d never used that word in Mongolian before – how had I avoided having to learn it when I’d dealt with everything from ornery horses to psychotic and potentially rabid dogs to drunk herders breaking into my ger?

I saw almost nothing of the valley we reached, except for the sites where we set the cameras. Those sites emerged out of the blinding white as we stumbled towards them, knee-to-thigh deep in drifted snow, the whole landscape eerie and markerless. We left the horses behind near a stone wall enclosing a hay field or corral and waded upslope. These stations we baited with the flanks of a goat, roadkill not being an option in Mongolia as it was in the US.

Dukhai, Aska, and Yelik setting up a camera. They did 100% of the physical labor since I couldn’t use my wrist. They deserve all the credit in the world for the success of this trip.

The crew resting at the top of the slope after wading up through the snow.

Mongolian snow conditions – never fun, but somehow still entertaining.

For our pains, whatever powers exist out there granted us bluebird conditions the next day, which took us up the north-facing slopes and through the thin larch forest to the base of the massive north-facing bowls. Where these bowls narrowed, and along obvious wildlife highways running east-west, we set the last of the cameras, baited with the rest of the goat.

On the north-facing slopes at the edge of the forest, glassing for elk, ibex, and argali

Yelik and Dukhai setting up a bait station.

I stayed high up on the mountainside, walking back along the wildlife trails; Yerlan and Jaksalak’s home was perched beneath the slope several kilometers to the east, and, in a move that probably fooled no one, I pretended that wading through the deep snow at high elevations for all of that distance was super fun, because my horse – which was really Aska’s horse, he’d trained it from a colt – had been edgy all morning on the ride out. I was happy to turn him over to Aska and hike back.

Headed home.

I hit a set of wolverine tracks and followed it up into the trees, out of sight of the group of men riding their horses across the plain below. Suddenly there was yelling, a huge commotion from the men, ringing dimly off the trees. I’d followed the tracks far enough into the forest that by the time I came back out, all I saw was the group of them leading their horses back to the house. They were on foot, which was strange, but I thought that they’d gotten off for a smoke break. I arrived back maybe a half hour after they did, opening the door and ducking into the dim light of the interior, ready to prattle on about the exciting wolverine tracks, but everything inside was silent and heavy and the hair went up on the back of my neck.

Yelik shook his head and said, in English “Today was so scary.”

Aska was lying on the floor, on the rolled out thin mattresses on which they slept, and I remembered the shouting and knew immediately that something had happened with the horse. And it had; while I’d followed those tracks up into the forest, Aska had stopped to take a photo. He’d spurred the horse to catch up with the others, and the horse had hit a wind-scoured snow drift; his front legs had plunged into the snow, Aska had slid forward so that his boots jammed into the stirrups, and then slid off the right side of the horse. In Mongolia horses are freaked out by anything approaching on the right, including riders who slide down on that side. The horse bolted, dragging Aska at a full gallop for somewhere between 30 and 50 meters through a boulder field. He was kicked in the shins, just as I had been, before he got free of the stirrups.

“I thought he was going to die,” Yelik said. And then he added, “Now I am nervous.”

Aska was stoic – more so than I’d been, definitely. His shins didn’t look bruised, although that didn’t mean anything; mine hadn’t visibly bruised either, but they ached terribly, some deeper, invisible bruise in the bone. More than the physical, though, he seemed shaken up by the flashbacks; after an hour or so he asked if I had any sleeping pills, because every time he shut his eyes he kept reliving the fall. I didn’t, but I gave him some advil and told him it should help, and apparently it did, because he said that he slept fine.

That night we enjoyed a final round of “Gulo gulo” over besbaramek. The next morning we set up a final bait station just above Yerlan and Jaksalak’s home. Aska hiked up with me to set the cameras, to prove that he was okay, and then rode his horse 40 km back to the town of Deluun. Watching him ride off so confidently, I took a deep breath and promised myself to stop being such a wimp about the horses henceforth. The enormous bruise on my butt, which I surreptitiously checked the day before when I was up in the forest alone, was starting to look less black and was fading to a violent dark purple. My wrist was still a problem, but I took the improvised cardboard brace off and decided to deal with it later, even though it still hurt to, say, hold a pen, braid my hair, or scratch my back. Horse danger was a fact of life in Mongolia and you either dealt with it or you were incapacitated by your need for safety.

The rest of us rode back to Deluun in a land rover. Over the winter, Aska would rebait the camera stations as needed, and Yelik would switch out the cards in December to see which stations were receiving wolverine visits. I was pretty sure that most of the bait would be devoured by foxes, but there were enough wolverine tracks to make me hopeful. Ultimately, we wanted to identify the best places to set up a trap or two for collaring, and, if we were very lucky, find places where multiple wolverines were visiting the cameras. The only thing to do now was wait, and head back to Khokh Serkh in hopes that we would capture that even more elusive animal, the snow leopard.

 

 

 

 

 

 

 

 

 

 

Return to the Altai

A couple of weeks ago I got a call from a colleague who suggested, politely but also pointedly, that I should probably start updating this blog again. I said yes, of course, I really had every intention of doing so, very soon.

Then, when I was on the phone with my parents yesterday, talking about my upcoming travel plans, my mother, politely but perhaps also pointedly, said, “Well, maybe this trip will provide some good fodder for your blog?” And I realized that I hadn’t even posted a single update about my upcoming plans, despite the fact that they are both wolverine-relevant and also pretty exciting.

Early tomorrow morning, I leave for Mongolia to set up camera traps in the Altai for wolverines. The Altai form Mongolia’s western border with China and Russia, and contain Mongolia’s highest peaks. The glaciated landscapes of Altai Tavan Bogd National Park are breathtaking, as I was made aware when I first visited this region in 2001. That was before I was very aware of wolverines, but not before I was aware of the other compelling denizen of the higher elevations of Asia, the snow leopard. I returned to Tavan Bogd and neighboring Khovd Aimag in 2010 to conduct interviews on wolverines and other wildlife, and had some thrilling encounters and near-encounters while I was up in the mountains.

This trip is in cooperation with a snow leopard project affiliated with the Denver Zoo, which means that I’m not only camera trapping for wolverines, but may also have the chance to fulfill a 17-year-long dream of seeing a snow leopard in the wild and participating in snow leopard collaring activities. So it’s pretty darn exciting. I’m also exhausted, however, and have about a dozen other writing projects right now, so sometimes it’s hard to remember to keep this blog up to date. But my mother is probably right – as mothers usually are. This trip should be story-worthy.

More details will be forthcoming once I reach Ulaanbaatar – thanks for reading and stay tuned.

 

Territoriality in Female Wolverines

For reasons that I’ll get into in a future post, I feel suddenly compelled to write up a quick literature review on the topic of territoriality in female wolverines.

Let’s get this out of the way immediately: female wolverines are territorial. This is evident throughout the recent literature. Out of concern for the safety of resident adult wolverines in the US, researchers generally don’t publish maps of wolverine home ranges, but anyone who has had the chance to look at the minimum convex polygons of study animals can see a pretty clear pattern. Adult female wolverines don’t overlap with other adult female wolverines. The territorial boundaries are pretty strict, often down a drainage that both animals will approach and traverse, but that neither will cross. There are instances of incursions and small amounts of overlap, but this is generally less than 2% of any female’s home range. Adult males are also territorial, but with varying degrees of territorial incursion or excursion. The territoriality of wolverines is one of the most important factors for understanding wolverine distribution, their natural rarity, and, importantly, conservation concerns and strategies as we look at a warming world.

Strictly speaking, a territory is a patch of ground that an animal defends, and a home range is a patch of ground that an animal occupies and uses for subsistence. In the wolverine research community, including in published papers, these terms are used in a conflating fashion, although some papers do make a distinction. In presentations and talks and casual conversation, we often use the words “home range” to refer to the area that a wolverine (male or female) occupies, but we mean this as a defended home range, which is actually a territory.

Territoriality in the Literature

While the territoriality of wolverines is widely understood at this point, I was surprised to note that there are few American or Canadian papers or book chapters that deal explicitly with the question of how territoriality functions, or the ways in which it potentially limits population in areas of restricted habitat where the population fragments into a meta-population structure. The Scandinavians, on the other hand, do tend to deal with territoriality, probably because the management imperatives are more urgent in places where depredation on domestic reindeer is a major problem. A Norwegian master’s thesis from 2014 looks at genetic sampling as a method to determine territoriality, in comparison to GPS collar data. Jens Persson’s dissertation deals in some depth with possible explanations for territoriality, and how those explanations may differ between males and females. Proving that the Scandinavians more or less own this topic, a 2017 thesis by Malin Aronsson closely focuses on the dynamics of territoriality and dispersal among female wolverines (and lynx). But the territoriality of the species is taken for granted in most publications, especially the North American publications.

I was also reminded of the absence of peer-reviewed publications focusing specifically on several of the major American wolverine research projects. Doug Chadwick’s popular-science book The Wolverine Way remains the best published account of the Glacier wolverine project. The Rocky Mountain Research Station has put out a number of impressive papers that draw on the Glacier data to ask large-scale questions about habitat relationships, population genetics, dispersal, and climate change effects, but the annual project reports remain the best source of information for the park population itself. The same is true of the Absaroka-Beartooth project, the project with which I got my start in the wolverine world, working as a volunteer. Peer-reviewed papers for that project were somewhat limited by the low numbers of detected wolverines within the study area – sample sizes and statistics being the perennial priority for most journals these days – but the eerie emptiness of prime modeled wolverine habitat deserves some consideration, hopefully in future publications.

Back in 1981, Hornocker et al published a study asserting that wolverines were not territorial. This was one of the earliest studies of wolverines in the lower 48, lasting from 1972-1977, on the Flathead National Forest. It was a telemetry study in which the researchers observed overlap among many different wolverines, and concluded that wolverines were tolerant of fellow wolverines. They reported “no intraspecific strife” and discussed how a wounded female wolverine, whose injuries they first attributed to another wolverine, were likely caused by a mountain lion. (Despite assertions that wolverines are not territorial, the home range maps that are included in this paper do show a familiar pattern – two male wolverines who don’t overlap, one female wolverine who sticks to a fairly tight home range, and a second female, overlapping the first, who makes wider movements that include the home range of the male who overlaps the first female. If I were to guess, many years later, what was up with this scenario, I’d suggest a male-female pair and their juvenile daughter, preparing to disperse. The second male looks like an unrelated individual as his range does not overlap with any of the other animals.) Earlier observational studies of wolverines, and books about the species, also fail to make note of territorial behavior. The same is largely true for the Mongolian hunters and herders who I interviewed; they were well aware of the wolverine’s rarity and ability to travel over long distances, but only a few noted that a wolverine would reappear in a particular spot at intervals. None of those interviewees made a leap to territoriality as an explanation, but some did refer (maybe jokingly) to a wolverine’s nutag, which is a Mongolian concept denoting an individual’s homeland.

Home range maps showing seasonal movements for four wolverines in NW Montana, from Hornocker et al 1981

Home range maps for four wolverines in NW Montana, showing seasonal movements, from Hornocker et al 1981

Observation, track surveys, and radio telemetry, of course, are limited in important ways. These methods allow glimpses of an animal only at the moments when the observer or listener happens to have their eyes or telemetry antenna trained on the animal. Finding dens is more difficult, which – in the absence of DNA techniques – makes understanding relatedness more difficult as well. With the advent of GPS collars and DNA analysis, we were able to observe wolverines more closely and consistently. Hundreds of locations for multiple animals, taken over months, in combination with VHF locations over the course of years, made the territorial behavior of the species clear. Den locations and kit collaring showed that wolverines will tolerate their own offspring within their territories for up to two years after birth. This could account for Hornocker’s and others’ observations of multiple wolverines sharing the same home range, and photos like those that Igor Shpilenok took in Kamchatka, of up to six wolverines on a bear carcass at the same time.

The Wildlife Conservation Society’s Yellowstone Wolverine Project likewise relied on annual reports and white papers to convey results for many years. The project director, Bob Inman, was in the process of getting his PhD, so his dissertation eventually yielded several published papers. Again, though, these deal mostly with larger-scale questions about habitat relationships and conservation priorities. Several of his papers do discuss territoriality, but again, for obvious reasons, most of the published papers don’t include home range maps.

What all of these papers and sources do include, however, is an assumption that territoriality is important. Some imply territoriality; for example, in a summary of draft papers from 2007, the WCS project notes in the abstract for a chapter on wolverine space use:

Mean annual (1 Mar–28 Feb) 95% fixed kernel home range size was 453 km2 for adult females (n = 15 wolverine years) and 1,160 km2 for adult males (n = 13 wolverine-years). Mean percent area overlap of same-sex adults was < 1% (SE = 0.00, range = 0–2%, n = 12 pairs) using annual 100% minimum convex polygon home ranges.

The “<1% overlap” suggests territoriality, although it’s not explicitly stated here. In a 2012 review of wolverine reproductive chronology, however, Inman et al do note this:

“Throughout its distribution, the wolverine displays extremely large home ranges, territoriality, low densities, and low reproductive rates (Copeland 1996; Inman et al. 2012; Krebs et al. 2007; Lofroth and Krebs 2007; Magoun 1985; Mattisson et al. 2011a; Persson et al. 2006, 2010). These adaptations are necessary for exploiting a cold, low-productivity niche where growing seasons are brief and food resources are limited (Inman et al. 2012).”  

Another 2012 Inman et al paper on spatial ecology does deal explicitly with the question of territoriality vs. undefended home ranges and is probably the most extensive discussion of this topic in the literature on wolverines in the lower 48. This paper does include some home range maps, with the locations stripped out.

Spatial distribution patterns of the Mustelidae are typically described as intra-sexual territoriality, where only home ranges of opposite sexes overlap (Powell 1979). Wolverine-specific reports exist for both intra-sexual territoriality (Magoun 1985, Copeland 1996, Hedmark et al. 2007, Persson et al. 2010) and for a high degree of spatial overlap but with temporal separation (Hornocker et al. 1983). Arguments against territoriality by wolverines include the lack of ability to defend such a large home range (Koehler et al. 1980). Our data on movement rates in relation to home range size, temporal development of the home range, minimal overlap of same-sex adults, and relatively immediate shifts upon a death suggest that wolverines are capable of patrolling a large territory and provide further support for intra-sexual territoriality. Reproductive success is closely correlated to the amount of energy that a female wolverine can obtain (Persson 2005), and for predators that are capable of individually acquiring prey, the presence of conspecifics reduces foraging efficiency (Sandell 1989). Since wolverines feed on individually obtainable prey and occupy relatively unproductive habitats, it follows that behaviors for maintaining exclusive access to resources would likely have selective advantage. Frequent marking behavior (Pulliainen and Ovaskainen 1975, Koehler et al. 1980) is likely part of an adaptive strategy that involves maintenance of exclusive territories within sexes so that feeding and breeding opportunities are monopolized by dominant individuals and their immediate offspring.

Female wolverine territories in Wyoming, with takeover of one home range by a female kit after the death of the resident adult female. From Inman et al 2012

The Scandinavian literature is also rife with references to territoriality among both male and female wolverines. Jens Persson, who works on wolverines in Sweden, reflects in his dissertation on the reasons for territorial behavior in female wolverines, and concludes that it’s related both to food, and also potentially to the need to protect kits against infanticide. Historically, it was widely believed that male wolverines would kill any kits they encountered, even their own; this has since been proven false, but the idea that males kill unrelated kits persists. Persson is the first researcher I’m aware of to suggest that female territoriality may actually be a defense against other females intent on infanticide.

Females could also gain from infanticide by eliminating non-related progeny to decrease future competition for territories or denning areas for her and her progeny. In addition, the death of an unrelated infant could also reduce the net reproductive success of a competitor (Hrdy & Hausfater, 1984). Competition for territories determine dispersal behaviour in female wolverines (Paper IV), suggesting that there is strong competition for territories among female wolverines.

 Wolff and Peterson (1998) hypothesized that a primary function of female territoriality in solitary mammals could be to protect vulnerable young from infanticidal conspecific females. Four predictions can be deduced from their offspring-defence hypothesis: 1) Female territoriality should be associated with young that are vulnerable to infanticide. 2) Female territoriality should be associated with defence of offspring, and therefore most pronounced during the offspring-rearing season. 3) Defence will be greatest against the segment of thepopulation that commits infanticide and against those individuals that females can dominate. 4) Optimal territory size should be a function of intruder pressure, intruder detectability, female response distances and offspring vulnerability, and changes in food abundance and distribution should not affect territory size directly unless they are correlated with the other factors. In concordance with predictions 1-3, wolverines have altricial young that are vulnerable from late winter until late summer (March – August) and female territoriality seem to be strongest during this period (Magoun, 1985; Landa, Lindén & Kojola, 2000). We lack data to evaluate prediction 4. However, in contrast to prediction 4, I believe that food actually is an important determinant of territory size in wolverine females (see Banci, 1994).

Malin Aronsson’s 2017 thesis examines the territorial dynamics of female wolverines, using the vast dataset from Swedish studies dating back to the 1990s. She makes some interesting observations about the counter-intuitive conclusion that wolverines are territorial despite living in low-resource environments, which is the opposite of what studies on other carnivores would suggest:

Wolverines are highly territorial (Persson et al. 2010), and by comparing space use overlap between years for the same individual I found that wolverines show high territorial fidelity resulting in a stable distribution of resident individuals. Interestingly, territorial fidelity in general is predicted to be low in habitats where food resources are low, variable, unpredictable or deplete fast (Wauters et al. 1995; Kirk et al. 2008; Edwards et al. 2009), which corresponds to the characterization of wolverine habitat in general (Inman et al. 2012b), and particularly in this study area (Person 2005). However, scavenging and caching are integral parts of wolverine biology (Inman et al. 2012b; Mattisson et al. 2016), which increase resource predictability, decrease depletion rate and create a valuable resource (i.e. cache sites) to defend, promoting high territorial fidelity despite the unpredictable environment (Tye 1986; Eide et al. 2004). In addition, occurrence of more efficient predators, such as the Eurasian lynx (Lynx lynx), provide carcasses for direct consumption and caching (Mattisson et al. 2011b). Furthermore, both males and females showed higher between-year fidelity at the territory level (i.e. 90% isopleth) compared to the core areas (i.e. 50% isopleth). That fidelity was lower at the core area compared to territory level suggests that it is critical to maintain the outer territory boundary to secure long-term resources, while the most used area within the territory may vary between years due to spatial fluctuations in key resources, or, for females, location of den sites may vary between years.

Aronsson also documents a few cases of territorial adult females shifting territories after successfully reproducing. Why this happened, and how frequently such moves occur, would be interesting questions for further investigation.

Another Scandinavian paper, a master’s thesis from 2014 by Espen Gregersen, compares home range and territoriality derived from GPS data to those derived from scat analysis. The question in this thesis was not so much “are wolverines territorial?” as “can wolverine territoriality be detected using non-invasive methods like scat analysis?” It’s an interesting question and one of relevance to those of us who have limited resources for large-scale trapping efforts in places like, say, Mongolia. Gregersen concludes that yes, we can indeed determine home range size and observe territoriality using scat samples – but it takes a very large number of samples. This thesis also addressed the question of territorial turnover after the death of a resident adult, which is particularly interesting at the southern edge of distribution, where wide separation of habitat patches makes recolonization less certain.

Finally, a forthcoming book chapter from Copeland et al. proposes a slightly different take on territoriality among male and female wolverines. That chapter will be out soon and I’ll look at it in depth once it’s published, but it too reinforces the idea that female wolverines are highly territorial, and maybe even more strictly territorial than males.

There are many other papers out there that include brief mentions of territoriality and intrasexual exclusion in home ranges. These are just a sample, and this write-up fairly cursory, but I hope they’re adequate to illustrate that wolverines – both male and female – are territorial.

Territoriality and Conservation

At this point, territoriality in wolverines is accepted as an important feature of their life history and ecology. The question of why hasn’t yet been answered, but the fact that wolverines require such large territories, and the fact that their reproductive rates are so low, accounts for their natural scarcity on any landscape – let alone one in which suitable habitat is located only at certain elevations in widely scattered patches across a sea of non-habitat.

Female territories structure the wolverine population. Females must have adequate resources to meet their needs and, hopefully, to reproduce. They occupy and defend territories that allow them to do this. Males in turn seem to select for territories that overlap with resident females. Whether this represents a territorial strategy for sexual monopoly, or whether it’s defined by the male’s capacity for paternal investment, or some combination, is worth investigation (male wolverines seem not to always entirely encompass a female’s territory, leaving her open to potentially overlap with other males, which raises questions about the accepted narrative of males “controlling” access to females). Both males and females disperse over long distances, although the longest movements have been observed in males like M56.

Habitat availability for females is the limiting factor on wolverine population growth and range expansion in the US Rockies. I’d hypothesize that keeping a certain number of territories occupied is critical to the long-term persistence of wolverines in the lower 48, and that there is some distinction to be made between female population numbers, strictly speaking; the percentage of habitat that’s occupied; and where that habitat is located in relation to other habitat. There’s been an enormous focus on “connectivity”– concurrent with the fashion for corridors among conservationists –  but a surprising lack of attention paid to the population nodes themselves. For example, the question that Gregersen raises about recolonization of vacant territories is interesting and important, especially given the observed disappearance of wolverines from places like the Tetons. Presumably this disappearance represents some kind of natural cycle of die-off for a relatively isolated population node, but how long does it take before those territories are reoccupied? And how is time-to-recolonization related to population density and occupancy of the next-nearest population nodes? Questions about functional connectivity among wolverine population nodes are important, but connectivity as a single conservation strategy for wolverines seems like an odd allocation of resources; wolverines don’t migrate, they disperse, and their dispersal patterns are unique and erratic. They are likely to benefit from the broad and intense focus on connectivity and road-crossing structures for other species, but trying to preserve wolverine-specific corridors seems like a good recipe for driving oneself nuts. As one of my Mongolian interviewees once said when discussing wolverines, “One day it’s here, the next day it’s 50 kilometers away. It could turn up anywhere!” I hope to see a greater focus on what’s going on within habitat in the future, including investigation of questions about what drives territoriality and territory size, and how territorial turnover works in a meta-population.

That’s it for now. If any of you have any thoughts about the function of territoriality in female or male wolverines, if you want to point out an obvious resource on this question that I overlooked, or if you just want to say hi, please feel free to comment.

References (with apologies for lack of consistent style formatting and for referring to multiple authors as “et al” instead of writing them out. Time constraints!)

Aronsson, M. 2017. ‘O Neighbour, Where Art Thou?’ Spatial and social dynamics in wolverine and lynx from individual use to population distribution. Doctoral dissertation. Swedish University of Agricultural Sciences. Uppsala. ISBN (electronic version) 978-91-576-8822-4

Chadwick, D. 2010. The Wolverine Way. Patagonia press.

Copeland, J. P., Landa, A., Heinemeyer, K., Aubry, K. B., van Dijk, J., May, R., Persson, J., Squires, J., and Yates, R. 2017. Social ethology of the wolverine. In: Biology and Conservation of Musteloids. Edited by David W. Macdonald, Christopher Newman, and Lauren A. Harrington: Oxford University Press. DOI 10.1093/oso/9780198759805.003.0018

Gregersen, E. 2014. Assessing territoriality in wolverines (Gulo gulo) using non-invasive genetic sampling. Master’s thesis. Norwegian University of Life Sciences.

Hornocker, M and H Hash. 1981. Ecology of the wolverine in northwestern Montana. Canadian Journal of Zoology. V. 59. pp. 1286-1301.

Inman et al. 2007. Wolverine space use in greater Yellowstone. In Greater Yellowstone Wolverine Program Cumulative Report. Wildlife Conservation Society.

Inman R. et al. 2012. The wolverine’s niche: linking reproductive chronology, caching, competition, and climate. Journal of Mammalogy 93(3):634-644.

Inman, R. et al. 2012. Spatial Ecology of Wolverines at the Southern Periphery of Distribution. Journal of Wildlife Management. 76(4). 778–792. DOI: 10.1002/jwmg.289

Persson, J. 2003. Population Ecology of Scandinavian Wolverines. Doctoral dissertation. Swedish University of Agricultural Sciences. Uppsala.

 

Support the Wolverine Foundation through Give Big Gallatin Valley

Wolverine enthusiasts, please consider supporting the Wolverine Foundation during the 24-hour Give Big Gallatin Valley fundraising event. It starts tonight, May 4th, at 6 pm and ends tomorrow, May 5th, at 6 pm. All donations made through TWF’s Give Big donation page during the event will be partially matched by the Bozeman Area Community Foundation, increasing the impact of your support for wolverine research and conservation.

The Wolverine Foundation has been integral to the advance of wolverine science and management over the past 20 years. The organization supports research projects with small grants, conducts education and outreach through talks at community organizations and schools, and supports researchers and students through dialogue, mentorship, and organization of workshops and other events.

Thank you!

 

Wolverines in “Wild Hope”

Last year, author Colleen Morton Busch contacted me to report a possible wolverine sighting in the Sierra Nevada near Tahoe, California. She knew that her sighting, lacking the evidence of photographs or DNA, wouldn’t be conclusive, but her descriptions of the animal she’d briefly spotted sounded distinctly gulo, and we suspected that Buddy, the California wolverine, was still somewhere in the area. We’re always conservative in assessing these sorts of reports, so I had to tell her that I couldn’t consider it a definite sighting, but I felt that it was probable that she’d seen a wolverine.

As we continued to email, the conversation evolved into a meditation on broader themes in conservation, and how those themes tied to Buddhism, with which both Colleen and I have some background. She wanted to write an article about her wolverine encounter that dealt with some of these themes, which made an intriguing divergence from the usual reporter inquiries about species biology and the policy situation around listing. Our ongoing email conversation was a highlight of last spring, particularly as she asked questions about the toll that immersion in the climate change scene takes on researchers. These are questions that people don’t usually ask, and that touch on the weights that we all carry; depression is common among climate researchers and people in affiliated fields. So it was wonderful to talk with someone who was aware of the dynamic between loving what you do, and constantly searching for some small hope – or, failing that, at least the equanimity to continue to love, and to accept impermanence, in the absence of hope.

Appropriately, then, Colleen’s article appears in the most recent volume of Wild Hope, a magazine that celebrates biodiversity and relates well-written stories of species accompanied by lush photography. There is no digital link to this article, but I’d encourage people to buy a copy if you want to read a great reflection on what wolverines mean to the people who are lucky enough to catch even a quick glimpse of one. As scientists, the emotional or psychological meaning of nature and wildlife is a topic that we’re wary of engaging with, but if we’re being honest, most of us would have to admit that we’re in this field in part because of our own dependence on the wild for some form of sustenance, and that we believe that protecting that source of inspiration is important for humanity. So it’s nice to read an account of how much a single, fleeting encounter meant to one person. As Colleen writes, “One wolverine sighting is likely all I’ll get in this life, so I’m grateful to have crossed paths ever so briefly. But seeing the wolverine lit a fire in me. It led to my education. And now I’m telling you, who may or may not live in a state where wolverines can be seen, but who are likely concerned about the changes we humans have wrought on our planet, about any threat of extinction, because the loss of the wolverine is connected to our shared future. Because there’s a glimmer of hope in an encounter between two beings – one wild and the other, a lover of wild things – even if it’s undocumented and unverified.”

A single wolverine encounter changed my life, so I understand this sentiment. There’s something uniquely compelling about this species, something that causes the mind to open in particular ways. Colleen’s captured that in her article, and that’s a great thing. Check it out.

 

 

Weal and Wolverines

Weal is an old word. It goes way back, to the days when a bunch of European tribes were squabbling over Great Britain: Roman invaders building walls to keep wild Celts and Picts from the civilized environs of their empire, Germanic and Scandinavian and Norman French invaders crashing onto the shores of an island where immigrants weren’t necessarily welcome, mixing up their genes and their languages and their culture. Whatever the disagreements of these groups as they contested over the British Isles, words akin to weal are found across large swaths of northern Europe, all related to a single concept: collective well-being. This is the word that gives us “well,” “wealth,” and “welfare,” as well as “Commonwealth,” a political entity that foregrounds the idea of shared responsibility and shared prosperity. Words with similar meanings are found throughout the world, so this is hardly an exclusively European concept; something in the human psyche acknowledges that we are, at our core, a social species responsible for our fellow creatures.

Today we understand wealth as relating to capital, material goods, and private property, but at one time wealth inhered in this shared investment in one’s community. When Puritans overthrew the corrupt monarchy of England in 1649 and decapitated Charles I – a man whose inflated self-opinion and dictatorial policies eventually became untenable to the British public – the nation’s briefly monarch-free government was referred to as a Commonwealth (This is about the time that the first use of the word “wolverine” is recorded in the English language, in customs forms related to fur imports). When those same English Puritans landed on the shores of North America in the 17th century, bringing with them all the good of their anti-monarchial ideals and all the ills of their colonial and religiously intolerant agenda, the land that they colonized eventually became the Commonwealth of Massachusetts, the birthplace of the American Revolution. And if there has always been a struggle between oligarchy and democracy in this country, if there has always been a tension between Enlightenment ideals and terrible colonial realities, the country’s values are nevertheless rooted in an understanding that we come to our community, and to its governance, in a spirit of both individualism and shared investment in the well-being of our fellow citizens.

What does this have to do with wolverines?

Wolverines, like all wildlife, are a public good. They don’t belong to any single person or interest group in the US, which means that we are collectively responsible for them. They are part of the weal of this country, part of the wealth we share. When we discuss what we know about wolverines, when we discuss management of wolverines, we’re talking about how to negotiate within a common-interest space for common-interest outcomes. This process is essential to democracy as well as to conservation of wildlife and the preservation of other environmental values that involve shared resources.

This reality rests uneasily next to a narrative that has gained increasing power over the past few decades, however: the narrative of unfettered neoliberal capitalism. The neoliberal narrative is a study in the privileging of special interests over the well-being of the collective of citizens known as society. It’s a deliberate turning of our backs on the idea that there is a reciprocal relationship between the individual and the world in which that individual lives and makes a living. Neolilberalism privatizes all profit, while socializing the risks and costs of profit-making. It consolidates capital among those who already have it, and denies the idea of the common weal by allowing those with capital to horde it without giving back and without taking responsibility for the ways in which  they impose on the public good. It puts a price tag on everything, and dismisses things that cannot be assigned monetary value. How much is a wild wolverine population worth to the public? This is hard to quantify. Easier to quantify is the value of profit made by oil industry executives and shareholders. The oil industry, in a world that extolls the neoliberal narrative, wins out over public interest. Neoliberalism is a powerfully destructive ideology, insidious and pervasive, and it is this basic set of values that will end up driving wolverines – and other climate sensitive wildlife – to extinction. Unless, of course, we have a massive society-wide awakening, immediately.

To that end, for those of you who are wolverine fans, I’d like to ask you to take a moment to reflect on your values. What are your priorities? How do these priorities potentially have an impact on society? What do you expect or feel entitled to in life, and what do you consider to be your obligations to the wider world? How do you define that wider world, and do you think are there limits to your obligations? If so, where are these limits? Likewise, if you feel like you are entitled to certain things, where are the limits on those entitlements, and do you extend the same set of entitlements to others? If so, which others?

These may seem like large and abstract questions, but I suspect that most people who are concerned with the persistence of wildlife fall within certain parameters when these questions are considered on a spectrum. There’s a lot of work out there in the social sciences on values orientation, the psychology of concern for in-groups vs. out-groups, and where environmental folks tend to fall out on these tests. For now, I’ll provide a couple of graphics and a set of questions to help you situate yourself within this conversation, because this issue of common interest vs. special interest will feature in upcoming posts and you’ll probably find yourself having gut-level reactions to some of what I write. You should know where those reactions are coming from.

Wolverine Quiz: What’s your in-group? 

First, let’s look at in-groups and out-groups. There’s a theory that people subconsciously define other people and entities as being relatively closer or relatively farther from themselves, and care about those people or entities to a degree that is dictated by that distance.

Beings that are closer to the self get more care. Beings that are further get less. There are entities that are seen as being definitively outside of the scope of care; those beings are the out-group.

In a very restricted or self-centered worldview, the in-group and out-group might look something like this:

In a very generous worldview, everything might be part of the in-group:

Note that these graphics should actually contain another dimension, which is time – for example, I consider living and non-living future generations, up to a certain point, as part of my ‘in-group,’ but I don’t really think about non-living past generations as part of my responsibility since – unless we really take it to a science fiction level – my actions can’t affect them. These are very basic graphics and very general explanations, but you probably get the idea.

Most people will fall somewhere in between the restricted and generous versions of the in-group/out-group dynamics above. Where do you fall? Who or what is in your in-group? If wolverines are in your in-group, why? (If they aren’t, what brings you to this blog?)

That question of why certain entities are included or excluded from our circle of concern leads us back to values. And that will be the topic of an upcoming post.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Nasty Cats Vote

Wolverines have dozens of diabolical nicknames, including “nasty cat.” Here’s a little doodle to encourage all the American wolverine fans to get out and vote tomorrow, if you haven’t already.