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APPENDIX III
Cascades Wolverine Project: Winter 2017-2018 Report
Prepared by Steph Williams, May 2018
509-699-9545, stephwilli@gmail.com
www.cascadeswolverineproject.org
Introduction
The wolverine (Gulo gulo) is a rare boreal carnivore inhabiting regions where snowpack persists
well into spring (Copeland 2010). In the Cascades, at the southern edge of their range, wolverine occupy
subalpine and alpine habitat, an ecosystem particularly vulnerable to long-term shifts in temperature
and precipitation. Wolverines were nearly extirpated from the Cascades by the 1930's, but naturally
recolonized part of their former range in Washington state by dispersing from Canada (Aubry 2007).
Presently, researchers estimate the population to be 30-40 individuals within the North Cascades (Aubry
2016), approximately 25 percent below carrying capacity. The number of wolverine across the
contiguous United States is estimated to be less than half of carrying capacity (Inman 2013). Primary
threats to this species' natural recovery include reduced spring snowpack, increased average maximum
summer temperature, habitat fragmentation, and disturbance secondary to trapping and recreational
activity (McKelvey 2011).
Nearly all contiguous U.S. wolverine habitat is federally managed. Though Washington state
considers the wolverine a Candidate Species, in 2014 the U.S. Fish and Wildlife Service (USFWS) denied
listing status. In 2016, the United States District Court for the District of Montana overturned the
USFWS's decision as "arbitrary and capricious." Federally-endowed protection remains uncertain. The
scientific community agrees that the wolverine lacks sufficient monitoring across the contiguous U.S.,
and likely faces a future challenged by climate change and other human disturbances (Inman 2013).
Winter recreation has the potential to impact wolverine recovery in the North Cascades. A recent
study in the Rocky Mountains of Idaho, Wyoming and Montana found altered behavior in breeding
females where winter recreation was relatively high, leading to potentially negative impacts on
reproduction and kit-rearing (Heinemeyer 2017). No such study has occurred in the North Cascades,
where winter recreation is rapidly increasing among backcountry skiers and snowmobilers. Engaging
winter recreationists with wildlife awareness in the North Cascades is beneficial in two primary ways:
first, to help mitigate potentially negative impacts to wolverine recovery, and second, to crowd-source rare
