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.


10 thoughts on “M56 Needs Some Friends

  1. I am all for reintroduction, long term it may bolster the genetic pool of Idaho’s meager gulo’s. Also looking forward to the lecture to be given in Sunvalley on 2/25. Additionally, a Boise lecture would likely be well attended with some advertisement. Please keep us informed on Colorado’s efforts.
    Great blog post thanks.

  2. I agree that a reintroduction in Colorado would be a good thing. I wonder how feasible it would be to track the individuals brought in as the reintroduction group, and then track via GPS collars/surgical implants the dispersal routes taken by following generations. It may be that these routes could highlight the corridors to the Wyoming population with the most potential to protect and enhance.

  3. Thanks for all your comments! I’ll float the idea of a Boise talk – good suggestion.

    Tim, I would think that tracking every one of those wolverines and their descendants would be critical to gauging the success of any reintroduction. I suspect that this will actually be a major logistical and financial challenge, because documenting reproduction is so difficult and tracking wolverines is so massively expensive. Along with the good care that CDOW is taking in addressing the social issues, this is probably another reason that we can’t leap with blind enthusiasm into putting wolverines on the ground in Colorado.

    I would also really like to see some more work done in Wyoming, first of all to assess ranges that haven’t been investigated for occupancy (the Winds, the Wyomings, the Bighorns), and second of all to see if there’s any reproduction beyond the Tetons, and if so, where those juveniles. and any Teton juveniles, are going. Wolverines in the Rockies are a classic meta-population and I think they have a lot to teach us about how meta-populations function (especially in times of ecological stress), and that those questions have a lot of relevance to how we might conserve them. It’s so difficult to get a grasp on the whole picture, but I think we need to strive to do so.

    Nate – let us know if you see any gulos up there in Alaska. 🙂

  4. Pingback: What to Expect When Your Wolverine Is Expecting « The Wolverine Blog

    • Thanks, Larry. I don’t know a single wolverine biologist who’s happy with the idea of “messing” with the animals. Thus far, given technological constraints, the only way we’ve been able to learn enough about the species to conserve it is to take some fairly invasive steps in order to keep track of the animals. I want to clarify that these are not just radio collars. They are GPS collars, which record information at very fine scales. The questions that these collars allow us to answer are likewise fine-scale questions about habitat use, territoriality, energetics, feeding habits, and reproduction. We trap for about three months a year, and the wolverines hold their collars for a few weeks to a few months at most. The amount of information that we obtain from this brief intrusion into their lives is huge. Nevertheless, I am sick to my stomach every time we have to handle an animal, and all the wolverine biologists I know experience a similar degree of worry over the well-being of the animals. We are required by state governments and our funders to pass stringent tests on handling methodology to make sure that the procedures are both safe for the animals, and justified by the need for information.

      There is currently an intensive effort underway to shift to non-invasive methodology (camera-trapping, hair-snaring for genetic monitoring, etc.) In an ideal scenario, population monitoring and large scale questions will, in the future, be answered purely through non-invasive means, with collaring reserved for finding answers to fine-scale questions that can’t be answered through genetic monitoring and camera trapping. This is the approach I’m taking in my wolverine work in Mongolia, precisely because I don’t want to stress the animals. It’s also cheaper and technologically more appropriate to the situation.

      I definitely understand the urge to just leave nature alone and let it function on its own. Unfortunately, though, given the degree of human encroachment on the ecosystem, and the extent to which even remote events (carbon emissions….) can have huge effects on local wildlife populations, leaving a wildlife population alone is no longer enough to ensure that it will be okay. There are some questions that can only be answered through research, and sometimes that research does involve invasive methodology. No one is happy about that, trust me, but if it answers questions that allow us to manage the species and landscape to better conserve them, then the payoff is worth it. I want these animals to survive and in order for them to do that, we have to understand their needs.

      I hope that our society one day gets back to a point where ecosystems can function fully and we can trust that all species will survive if left to their own devices.

  5. I think the reintroduction is a great idea as long as. The Ski industry is not hurt with rediculous restrictions. Hunting season is not affected. Roads are not closed. Logging is allowed to continue removing those beetle killed tree’s. In other words most people don’t mind or won’t mind as long as people’s freedom’s and rights are upheld on public land. They were able to reintroduce Lynx without placing restrictions on public land so why not again. I think it would be great to see a few Wolverines while out snomobiling or back packing! In Wyoming and Montana groups like defenders of wildlife and the humane society really showed their true colors as no nothing idiots when it comes to protecting wolves and grizzly bears. The wolf population is now at 3000 or more in ID, MT, WY, and this is being supressed by the money these organizations have spent (hush money). Their goal is to outlaw hunting which is the very reason states like our’s have so many Elk, deer, pronghorn, and moose. The fact is we don’t need apex predators because our hunters do such a incredible job managing our wildlife already! I guess what I’m saying is that because these groups keep Grizzlies and wolves on the endangered species act ( when they are not endangered) also endangers the whole ecosystem. They say the Northern Yellowstone elk heard will not make it another 5 years unless they can drastically reduce wolf numbers. That kind of management is like letting a teenager manage a multi million dollar business with no experience. Wolverines are not wolves or grizzly bears so I say let’s do it. As long as common sense not politics gets in the way!

    • Thanks for your support for the reintroduction.

      This really isn’t the place to get into bear or wolf conservation issues, but just to cite a statistic, wolf numbers in Yellowstone are down 23% in the past year, and average litter size is decreasing (http://www.nps.gov/yell/naturescience/wolves.htm). A species can’t survive without its prey base, so to a certain extent these things are self-limiting. I think the elk will be okay.

  6. Pingback: Colorado: Wolverine recovery plan on hold for now « Summit County Citizens Voice

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