Montana Dept of Fish, Wildlife and Parks maintains wolverine trapping.
At their August 2, 2012 Commission meeting, the Montana Dept of Fish, Wildlife and Parks (MDFWP) commissioners voted to continue trapping wolverine, despite a petition from eight environmental groups and one individual George Wuerthner (me) to halt trapping. The groups– which included Friends of the Wild Swan, Helena Hunters and Anglers Association, Montana Ecosystem Defense, Native Ecosystems Council, Alliance for the Wild Rockies, Swan View Coalition, Wild Earth Guardians, and Footloose Montana—argued that wolverine trapping could pose a threat to the long term survival of wolverine in the lower 48 states.
The US Fish and Wildlife Service estimate that there are no more than 250-300 in the lower 48 states. In 2010, the wolverine was listed as a candidate for listing under the Endangered Species Act. Sadly the MDFWP once again demonstrates a willingness to ignore the social ecology of carnivores which makes them more vulnerable to threats than other species.
BASIC ECOLOGY AND GEOGRAPHY OF WOLVERINE
Wolverine are both predators and scavengers. They will eat anything they can, and have the jaws to prove it. One study used bear traps to capture wolverine alive for radio collaring. These traps are large barrels with cyclone fencing as the sliding trap doors. The researchers learned the hard way that they had to check traps frequently. One wolverine managed to chew his way out of the cyclone fencing!
At one time wolverine were far more common, and ranged from Maine across the northern states and from Montana to New Mexico in the Rockies and from Washington to California’s Sierra Nevada.
Today in the Rockies only Montana, Wyoming and Idaho still have breeding populations. A few wolverine may still inhabit California. Wolverine have recently been documented in eastern Oregon’s Wallowa Mountains. Washington’s North Cascades are also home to the animals. Of all the remaining states with wolverine, only Montana still allows trapping.
Wolverine in the lower 48 states tend to be found at or near timberline—or where there is perpetual snow—especially late in the spring. Females rely on food caches that are hidden under snow to feed their young during the breeding season when they are largely restricted to the den attending to their young. As high elevation snowfields shrink as a result of global warming the wolverine’s habitat will shrink.
Wolverine are long distance travelers. I remember an anecdote that Maurice Hornocker gave in a talk he presented in Missoula in the early 1980s on his wolverine research in the Northern Continental Divide. One of the points that Hornocker made was that wolverine can cover a lot of territory. He told of one radio tracked individual who was trapped by Glacier, and a week later was found in Lincoln—about a hundred miles as a crow flies, and much further by the route the animal traveled. A week later, this wolverine was back near Glacier. We now know that such travels are not unusual for wolverine. Hornocker hammered home that seeing tracks in a lot of places doesn’t necessarily mean there are a lot of wolverine.
TRAPPING IGNORES SOCIAL ECOLOGY OF WOLVERINE
One of the problems of low wolverine numbers is that it’s easy to wipe out the species from a mountain range and it may be a long time before that range is recolonized. It’s the perfect island geography effect. Populations are lost gradually mountain range by mountain range until at some point they cannot recover. Many of our western wolverine populations are “island populations”. And since even the loss of one or two breeding animals could cause an island population to spiral down to zero, it’s easy to see how wolverine in various places can wink out. We may be at that point now.
While the best estimate of the wolverine’s population by the Fish and Wildlife Service for Montana is 150-175 animals, the “effective” breeding population of wolverine may not number more than 30-50 individuals. That is because females usually take a year off between breeding and typically one male breeds several females. Thus the genetic diversity of wolverine in such a population is exceedingly small.
Even the loss of a few breeding females can be problematic. It’s quite possible that Montana’s wolverine population is already too small to remain genetically viable over the long haul. Montana allows five total wolverines, or three females, to be trapped each year. This does not include animals that may be maimed but escape the traps, only to die later.
The loss of 2-3 animals a year to trapping may seem inconsequential—unfortunately that is the argument that MDFWP makes in defense of its continuation of wolverine trapping. Depending on which animals are caught, It can be detrimental the long term survival of Montana’s wolverine population. If, for instance, 3 breeding females were taken, you are not only taking those three animals, but very likely the kits they have produced as well, since they are likely to die of starvation once the mother is killed. Alternatively if a breeding male is trapped, any new male who sets up a territory often attempts to kill any young so as to induce females to breed sooner. Thus the loss of just a few females and/or the loss of breeding male may result in the loss of 10%–15% or more of the effective breeding population. Throw in other sources of mortality–which exist all the time–and it not too extreme to argue that trapping could be the straw that breaks the proverbial camel’s back.
FISH AND GAME AGENCIES FAILURE TO MANAGE CARNIVORES
The fact that the MDFWP ignores this social ecology of wolverine is not surprising. Fish and Game Departments seem incapable of thinking beyond populations. They ignore the social ecology of all predators in their management decisions.
One of the principles of good science is the precautionary principle. In the absence of any good counter information, one should err on the side of caution. Trapping wolverine is not operating on the side of caution. There is no evidence that trapping of small wolverine populations is sustainable, and some science that suggests it may harm the species. Therefore, one should, in my view, err on the side of the wolverine, not the trappers.
The unwillingness to ban trapping in spite of the low population and numerous threats to the long term health of wolverine populations demonstrates, in my view, why Fish and Game agencies, cannot be trusted to manage wildlife in the best interest of the public, and of course, wildlife.
When push comes to shove, and if there is any doubt about whether human activities harm a species, particularly human hunting, trapping and fishing, these agencies always side with trappers, hunters and anglers, not the wildlife. Their default mode is keep killing the wildlife until it can be demonstrated beyond a shadow of a doubt that human exploitation is harmful—rather than exercising reasonable caution.
Significantly at least one hunting organization, the Helena Hunters and Anglers Association also signed the petition. The Helena organization deserves a pat on the back for having the moral courage to challenge the trapping community.
MDFWP says it’s OK to trap an animal that is a candidate for listing under the Endangered Species Act. Does that sound reasonable? Even if trapping really didn’t pose a threat to the animal, allowing trapping of these animals suggests to many people that wolverine populations are doing fine. That is not a message that MDFWP should be putting out given what we know about the threats to the long term viability of wolverine in Montana.
All state wildlife agencies express anger and outrage whenever species are listed under the federal Endangered Species Act arguing that they are fully capable of managing wildlife. Yet time and time again they prove otherwise. If state agencies were doing the job they are empowered and trusted to do, we would have a lot fewer endangered species. But these state agencies lack the moral courage and political fortitude to oppose industries, as well as other constituency such hunting, fishing, and trapping groups that they see as their prime supporters.
Once again Fish and Game departments have demonstrated in my mind, that they are incapable of managing carnivore species. It’s not that they lack the scientific knowledge—there are many fine biologists working for these agencies. Rather it is an unwillingness of their directors, commissions, and others to stand up for wildlife in the face of political pressure from hunters, trappers and anglers. As a consequence, these agencies are shirking their moral duty and legal public trust obligations to manage wildlife for all the public and for the long term health of the species under their care.
– – –
George Wuerthner is an ecologist, and a former Montana hunting guide.