January 2025 - 14

IN THE FIELD
Wolverines in the Winds
Recent project efforts provide behavioral, reproductive
and demographic information
By Dean Clause
D
uring the 2022-23 winter, Wyoming
Game and Fish Department and
U.S. Forest Service biologists pursued
a unique opportunity to capture
and place GPS transmitters on wolverines
in an effort to gain knowledge on behavioral
movements - daily and seasonally - and
general demographics along the west slope
of the Wind River Mountain Range where
no comprehensive data of this kind existed.
One year prior to the trapping and collaring
efforts, a monitoring survey station used to
document wolverine presence experienced
repetitive wolverine visits by two distinct animals.
This survey location was selected for
base trapping during the 2022-23 and 202324
winters. This project hopes to provide a
better understanding of wolverine ecology
in the Wind River Range for management
planning and environmental analysis, as well
as further knowledge about wolverines and
future research needs on a species where limited
data exists.
Findings to date
During the first two years of the project,
biologists made several significant findings
and identified additional questions to be
answered. An adult female wolverine was
caught and collared with a GPS transmitter in
March 2023 during the first winter of project
work, resulting in 973 unique locations over
a four-month period. The GPS data maps a
territory the size of roughly 143 square miles
and a perimeter covering more than 48 miles.
In addition, a natal den site was identified
and confirmed later by a site visit. Two young
wolverines, called kits or cubs, were located
by a fixed-winged flight in mid-June 2023,
confirming the first reproductive female documented
in the Wind River Range.
Other interesting findings, although not
uncommon to wolverines, include variable
14 | January 2025
A collared female wolverine with kits located near a rendezvous site in June 2023. (Photo by Mark Packila)
Two young wolverines, called kits or cubs, were located by a fixedwinged
flight in mid-June 2023, confirming the first reproductive female
documented in the Wind River Range.
distances traveled during daily outings from
a few miles to as far as 11 air miles one-way,
and durations ranging from four to 30 hours.
The daily movement pattern suggests not only
was this female making daily trips to known
food sources or caches, but the den site was
somewhat central to these food sources within
her home range.
Daily movements showed topography
ranging from 8,500-12,000 feet in elevation.
Clusters of locations where wolverines
return or spend much of their time have
intrigued biologists. Investigations to date
have correlated many of the clusters to food
sources, and many clusters are near or at
fall hunt harvest sites, primarily elk. Some
clusters showed only scat piles, possibly indicating
resting and security locations below
the snow surface near the ground level that
is warmer to maximize thermoregulation.
One of the largest clusters had more than 70
locations used during June and was identified
as a rendezvous site - a site used to relocate
kits after vacating the natal den site - where
the remains of a black bear carcass was cached
and eaten.

January 2025

Table of Contents for the Digital Edition of January 2025