Sawtooth Association

The Alpine Examiner

May 10, 2023

Naturalist Blog

Getting to the heart of what matters in the Sawtooth National Recreation Area

Winter Recreation and Wolverine Habitats

SIHA 2020 Naturalists

Winter recreation is an ever-growing industry, especially in the western United States. Backcountry recreation such as snowmobiling and skiing is a culture of its own. As much fun as skiing feet of untouched fresh powder is, there are consequences that come with it. There is a growing need to understand the different impacts recreation, especially winter recreation, has on wildlife. 

There have been several studies that look into how different recreation activities are affecting wildlife. Heinemeyer et al. (2019) looked into how wolverines (Gulo gulo) habitats have been effected by backcountry winter recreation. Wolverines are an ideal wildlife species to study because their habitats are in high alpine and subalpine locations where winter recreation tends to take place. Wolverines favor places that have deep and persistent snowpack into late spring, much like most winter recreationists. Wolverines may be more vulnerable to recreation use than other wildlife species because they naturally occur at lower densities, have lower reproduction rates, and remain active all winter, rather than hibernating. Females make their dens in deep snowpack and their kits are born in mid to late February through early March. 

This study monitored the movements and habitat use of wolverines in four different study areas across the Rocky Mountains of Idaho, Wyoming, and Montana. They collared and GPS tracked 24 wolverines, 11 female and 13 males, over the course of five years. Along with this, different winter recreationists were monitored and tracked to characterize the spatial extent and intensity of recreation. 

The study found that both females and males did show negative responses to the increasing intensity of winter recreation within their home ranges. Off-road recreation activities had a stronger impact on the wolverine’s habitat than recreating along roads and groomed routes. 

Wolverines will avoid areas that are frequented by winter recreationists. This study suggests that by avoiding these particular areas it may result in indirect important habitat loss. From looking at models they have found that winter recreationists have the largest impact on female wolverines. They rely on those remote areas with deep snowpack for denning and their habitats are being impacted. Females are also more sensitive to disturbances from industrial activities, such as snowmobiles. 

(photo source: wikipedia)

Climate change is another important part of this study. Wolverines are already vulnerable to climate change because they rely on persistent spring snowpack and with warmer winters they are having to go higher and higher. Winter recreationists are facing the same issue. Their activities are becoming more concentrated and intense in both space and time, especially during mid to late winter period. This is when the snowpack is predicted to be the most consistent, but this is also when female wolverines are entering their dens. With the winter recreation distribution and increase of intensity this study believes that there can be even more severe indirect habitat loss than originally thought. 

Overall, reproductive success is linked to the success of reproduction. The loss of habitat due to anthropogenic influences can affect both the reproduction and survival of animals, such as wolverines. This study does state that they did not have all the information to assess the population level being effected by winter recreationists, but they did see a significant avoidance from wolverines in areas used by backcountry recreation. This does result in an indirect loss of habitat, especially for female wolverines. 

This research was done to help provide land managers with a better understanding of crucial habitat characteristics used by wolverines. They hoped it would help inform management of wolverine habitats across the vast landscapes they call home. 

So, next time you are out backcountry skiing feet of deep powder keep in mind all of the habitats that you are around. Even in the snow, there are many animals, such as wolverines, that rely heavily on those remote areas. Enjoy the fresh turns, but always be mindful of who else shares these beautiful landscapes with us. 


This blog was written by a SIHA 2020 Naturalist.