Two weeks ago, Montana Fish, Wildlife, and Parks and the coalition of environmental groups who sued the state to end wolverine trapping withdrew from a hearing that was scheduled for January 10th, after the USFWS indicated that they will recommend wolverines for listing under the ESA. This meant the total closure of the 2012-2013 trapping season and, pending the ESA recommendation, possible closure of wolverine trapping in Montana until the species recovers. The relief among wolverine enthusiasts, advocates, and researchers was tempered by Montana’s announcement that they will pursue an exemption if the species is listed, in order to continue to trap. Presumably, the legal argument for an exemption comes from the fact that, in the 2010 “warranted but precluded” decision, climate change is listed as the primary threat, with trapping as a secondary factor. Advocates issued responses (here and here) condemning Montana’s decision and deriding MFWP for “brash intransigence” and for making politicized decisions that ignore the “best available science.”
While all of this has been unfolding, I’ve been involved in some wider discussions, and some private consideration, about what science is, what it means when an individual claims to do science or to be a scientist, and the consequences of granting prestige to ‘science-based decision-making,’ especially in a culture where scientific literacy remains hazy. I could take this post in several directions, all of which I hope to eventually address on this blog, but I am going to focus here on the immediate questions at hand: What is going on with these competing claims about managing wolverines based on the “best available science?” What is the “best available science?” And is it possible that no one is incompetent in this scenario, and that two sets of science, with evidently conflicting results, are both correct?
Here’s the background – MFWP contends that it has managed wolverines and continues to manage wolverines based on ‘sound science,’ and that years of data from track surveys and from carcasses turned in by trappers suggest that the population is healthy enough to bear the low levels of mortality caused by trapping (the current season is set at five individuals, with a female subquota of three.) They claim that wolverines have continued to expand their range despite a season that until a few years ago had no quota. They are also defending a methodology that they developed at a time when no one else was keeping track of wolverines at all and when there was very little precedent – or technology – available for more sophisticated studies. This methodology was applied, and apparently worked, for decades, and institutions are slow to change systems that have worked.
Over the past 15 years, however, a set of studies, funded and implemented by federal agencies (including the Forest Service and the National Park Service) and non-profit research organizations (including my host institution, the Northern Rockies Conservation Cooperative, as well as the Wolverine Foundation, the Wildlife Conservation Society, and a number of others) have employed much more sophisticated technology and analytical methods to investigate wolverine populations in the Rockies. Many of these studies have been based primarily in Montana, but they have also documented reproductive wolverine populations in Wyoming, Idaho, and the Cascades, and dispersers as far abroad as Colorado, California, and eastern Oregon. These studies suggest two things: the wolverine population in the western US is indeed continuing to expand, and it is also under threat from shrinking snowpack as temperatures increase in the face of climate change. Taken together, the research from both MFWP and these wider studies paints a striking and complicated picture: a story of a species that is poised at a tipping point between a triumphant, unassisted return to habitat from which it was extirpated a century before, and a coming century in which the species might suffer a second extirpation, much more final than the last. These stories both seem to be true, and like everything else about the species, the conservation debate is therefore uniquely challenging.
Both sides of the discussion want to default to well-worn arguments: the advocates claim critical danger (in some cases, erroneously, because of ‘declining populations’) and the pro-trapping managers claim that the rebounding population indicates that there is no problem with removing such a small number of animals each year. I obviously am a biased individual in this debate, and those biases run too deep for me to be truly objective, but I hope that I can make an honest attempt to illustrate why we need to push for a different understanding of conservation when we think about wolverines, and why that understanding can encompass both of these perspectives and still end up requiring the closure of the trapping season. So let’s start, today, with how you do ecological research. Later this week, I’ll get into the implications of the science that has been done, but for now, I’ll focus on the question of scale.
When you ask an ecological question, scale is one of the most important and immediate parameters to define. There are several types of scale to consider, and the most obvious is geographical scale. For example, if you’re interested in wolverines, are you interested in a single population node (a mountain range with at least one reproductive female), several interacting population nodes (say, the several occupied mountain ranges of southwestern Montana and northwestern Wyoming), or the entire metapopulation of the US Rockies, the Cascades, and maybe even the Sierra Nevada? You can ask the question “Is the population healthy?” at one geographical scale, and get a very different answer at that scale than you might at another scale.
In the world we live in, we also have to consider questions of jurisdiction, and whether or not we are spatially bounding our questions based on political borders. If we are, we have to ask whether imposing these artificial boundaries on our research limits the results – in other words, if we’re asking questions about twenty population nodes in a metapopulation that contains a hundred population nodes, are our answers applicable to the entire population? Or just to our study nodes? And if we ask only about the population nodes within our jurisdiction, are we confident that we understand the relationships among the study nodes and the nodes outside the study area?
Scale is also temporal, and temporal scale is directional, so your questions and your answers will be further bounded by whether you ask about trends that have occurred in the distant past or the recent past, and trends that you predict in the immediate future or the distant future. The question “Has the wolverine population in Montana been healthy enough to bear trapping in the past century?,” is substantially different from “Is the wolverine population healthy enough to bear trapping for the next two decades?” And that question, in turn, is different from the query, “Will trapping now have an effect on wolverine populations a century from now?”
These are management questions, not questions about simple knowledge (“What happened to the wolverines of Maryland, Virginia, Spain, and the Czech Republic at the end of the Pleistocene?” is an example of a question that is mostly about knowledge, with very few management implications) and at this point in the post, there’s an implicit subtext involving the influence of values on science and management, but we’ll get into that later. Right now, I’m going to assert that wolverines exist in a metapopulation that is interconnected throughout the Rockies, and that we must ask questions at that scale, and with a forward-looking temporal orientation, if we are going to figure out how to conserve the species.
MFWP has been asking questions about the population in Montana, based primarily on data and trends from the past, and without a clear articulation of how those trends might change in the face of climate change. The broader body of science conducted by other agencies and groups has been asking forward-looking questions, with data-collection frequently occurring at limited scales (Glacier National Park, the Greater Yellowstone region, the Payette National Forest) but always with a view to extracting broader trends in addition to information about specific populations. Papers like Copeland’s 2010 article on climate change and snowpack, Inman’s recent work on habitat modeling, and Schwartz’s papers on genetics all come out of large-scale questions.
Wolverines are in a unique situation: a once wide-ranging species was inadvertently extirpated and then began a process of recolonization that was monitored for decades by a state management agency at a small scale, and then other scientists began larger-scale studies that included some speculation about the future, and the results have entered the conservation debate at a moment when the trends of the past will be skewed by unprecedented climate disruption in the future. If we hope to protect the species, the science that we look to for management insight will have to be multi-scale, and it will have to integrate past trends with what we know about wolverines’ habitat requirements and our understanding of what will happen to that habitat in the future. There are, of course, serious political considerations at play in the discussion as well, but from a purely scientific standpoint, this is how these different studies operate and interact – not entirely at odds with each other, but at different scales, using different methodologies, and looking in different directions.
This is a pretty basic analysis. I have a series of doodles, constructed while watching the series Firefly during an epic descent into purely visual thinking (more about that later, too), which attempt to illustrate a model that encompasses both sets of science and that also tries to create a working picture of a wolverine metapopulation from 1900 through about 2100. Needless to say, it’s pretty rough, but if I can make it comprehensible, I might put a version up here. In the meantime, here’s another article, concise but nuanced, that also features a video of F5 in one of the live-traps in Glacier. This film highlights the endearing nature of the species. Enjoy.