Northern Wolverine Project

Year End Final Report - April 2000

Wolverine Ecology in Plateau and Foothill Landscapes 1996-1999

AUTHORS:

Eric C. Lofroth, Ministry of Environment, Lands and Parks, Victoria, BC, Canada
Debbie Wellwood
William Harrower
Corinna Hoodicoff

Executive Summary:
The Northern Wolverine Project was initiated in 1996 to document the distribution and abundance of wolverine in plateau and foothill landscapes. The overall objective was to improve the basic ecological knowledge on wolverine in order to facilitate better science-based management. This year end report summarizes data collected from 1996 until March 1999. Selected data sets within the report contain more recent data.

The 8900 kmē study area for the Northern Wolverine Project was established on the west side of Williston Reservoir in the Manson, Omineca, Osilinka and Mesilinka drainages. Four biogeoclimatic zones and 7 subzone/variants are represented within the study area. The study area contains considerable forest harvesting activity, major logging roads, a power transmission corridor, a hydro-electric reservoir and sixteen registered traplines.

Thirty five different wolverine were live-trapped and instrumented with radio-transmitters (collars or implants) during the reporting period. Radio-instrumented wolverine were located on a weekly basis during the reporting period. Home ranges averaged 521.5 kmē for adult females, 1756.1 kmē for adult males, 1502.3 kmē for subadult females and 3118.6 kmē for subadult males. Adult females were located at higher elevations, on average, than all other sex and age classes during all seasons. They made substantial use of alpine and subalpine habitats, particularly when raising young. Primary food items during this period were caribou and marmots. Adult males and subadult females were found at high elevations during the breeding season. They and subadult males made substantial use of low elevation habitats at all other times of the year. Moose were the most common food type during these times. All sex and age classes used older aged forests far more than other successional stages. Snow trailing activity indices were greatest in the old growth successional stage.

Survivorship rates were 65% overall, with adult females having the highest rates (90%) and subadult males the lowest (20%). Sources of mortalities of monitored wolverine included trapping, con-specific mortality and natural causes. Five of 9 adult females monitored during this period had maternal dens in one or more years. Maternal dens were located in high elevation, subalpine cirques and talus slopes.