Amid the technology age of satellite mapping and swelling popularity of trail cameras, wildlife experts are still tapping the fur trappers’ knowledge to seek out important data on elusive predators.
In Alberta, for example, biologists are looking to gain a better understanding of wolverine distribution across the Canadian province, and reaching back through decades of trapper reports and observations to do it.
The information gained from local trapping data has helped experts broaden their knowledge, according to a recent release from The Wildlife Society.
Although fur harvest reporting historically provided information on where wolverines had been trapped, researchers lacked data on where wolverines continued to occur (not harvested). Surveys specific to the status of wildlife observed on rural traplines hadn’t been conducted since the 1980s, despite many individual trappers showing interest in contributing to ongoing research since that time.
Tap the trappers!
And so the research began, to assess observations of wolverines across the province and examine relationships between where trappers observed wolverine, either through direct sightings, harvest, or tracks, and the landscape variables that could affect wolverine distribution in the future.
“This idea of gathering this local ecological knowledge that the trappers have gained through decades and spending lots and lots of time in the same area has some different value than other types of studies we do,” says Robert Anderson, a wildlife biologist with the Alberta Conservation Association told The Wildlife Society in October.
“Some of these trapping areas, if you wanted to go down and grab a coffee at Starbucks, you’re talking about six hours.” he continued, noting that many of the areas where wolverine insight was desired were remote and difficult to gain knowledge about.
Biologists turned to the Alberta Trappers Association, who are currently also working with biologists in Washington state on Fisher reintroduction, to survey licensed trappers across the province. Trappers returned questionnaires from 164 different trapping areas throughout the region.
The focus of the study areas were primarily on registered fur management parcels of public lands, as these areas required specific registrations with trappers that have held rights to these boundaries spanning multiple decades. This allowed trappers to acquire in-depth knowledge of a specific area over a constant, extended period of time; gaining intimate knowledge into the landscape along the way.
The insight gained from those trapper surveys were part of a recent study in the Wildlife Bulletin, in which Anderson co-authored.
Trappers were asked to provide information about observations of wolverine sign, harvest history, and their own opinions about wolverine population trends. Researcher analysis was focused on areas with reports of wolverine occurrence.
Those trapper observations of wolverines, which were combined with other research methods, found that wolverines (Gulo gulo) are associated with cooler climates, as well as a myriad of other findings.
Not All Wolverines who wander are lost!
Intact forest was found to be integral - having some of the best wolverine presence in any of the three environment types studied.
Remoteness, and lack of human disturbance were also important factors, according to the study. Observations have found that fewer wolverines were documented in these heavily modified landscapes. Of those wolverines, most were hesitant to climb baited trees and spent considerably less time at camera trap sites, compared with wolverines observed in less developed terrain.
A wolverine scales a tree. (Photo | Vincent van Zalinge)
These findings tend to separate existing wolverine trends from those of its smaller cousins - fisher, mink and weasel; which appear to be adapting quite well to more urban and agricultural landscapes across Alberta and the rest of their range in North America.
Researchers also found that the wolverine, synonymous with mountainous ranges of the Rocky Mountains and other high snowfall climates, actually appears to be making good-use of non-mountainous Boreal forest (over 80-90%).
Trapper involvement helped with a follow-up study on denning characteristics, also co-authored by Anderson and featured in The Canadian Field-Naturalist publication, which set out to better understand the harborage areas for wolverines amid less snow cover in lower areas.
While wolverines in mountainous areas utilize deep snow-packs for denning, the voracious animal was found to use ground hollows from uprooted spruce trees in lower-level Boreal habitat, where snow packs tend to be less accumulative.
According to the study, wolverines are a “conservation conundrum” because they occur at low densities, have low reproductive rates, and occupy larger home ranges in more remote areas.
Wolverines are managed as a sensitive furbearer with an annual harvest limit of 1 wolverine per trapping area per year.
“Historically, the distribution of wolverines and other fur-bearers in Alberta was largely derived from fur trapping records, trapper questionnaires, and anecdotal information.” the study states. “A trapper opinion survey suggested that the wolverine population may have been declining by the mid‐1980s and a later fur harvest analysis also showed reduced distribution over time.”
However, more recent fur harvest analyses suggest that wolverine harvest density actually increased from the 1990s to the 2000s, particularly in the north-western Boreal Forest region.
The information gathered in the study isn’t just integral to researchers. The findings are important for local trappers as well, who can utilize improved knowledge of wolverine characteristics to implement in future trapping/management endeavors, help advocate for greater habitat conservation measures, and broaden understanding of the animal’s range.
The study recommends that wildlife managers conduct “periodic surveys with trappers to assess the status and distribution of wolverines, as well as landscape features that may be associated with their occurrence.”
The study goes on to state that “engaging trappers in research may carry the ancillary benefit of promoting trust in the information among the trappers… By doing so, they will be helping to manage resource development and conserving land for the benefit of wolverines and many other species that they value.”
(Photo | Vincent van Zalinge)
Both members of the weasel family, fisher and marten tend to inhabit similar areas within their habitat range while competing with one another over valuable resources and food within that habitat. However, while the larger Fisher has managed to adapt immensely well to agricultural, suburban, and slightly more southern expanses of its home range, the marten is far more fickle with regard to altered habitat impact.