Esker Habitat Studies in the Slave Geological Province:
Movements and Habitat Use of Wolves Denning in the Central Arctic,
Northwest Territories and Nunavut, Canada
Organization / Researcher(s): GNWT, Dean Cluff; DIAND, Stephen Traynor
Length of Project: 3 years (1996-1999)
Personnel involved: GNWT component - a graduate student; Dene elders and seven community based volunteers from Lutsel K'e and N'Dilo participated in some of the flights for radio tracking and den site observation. DIAND component 3 researchers and 3 co-op students
Total Project Expenditures: $498,389
Eskers, the long ridges of sand and gravel left behind when the glaciers melted, are important for many reasons. Of interest to this study is their use by Gray wolves as denning habitat. Eskers are also valued as a source of gravel and sand for roads, airstrips and other development infrastructure. Archaeological sites are often found on eskers. This project provided baseline information on eskers in the study area. Eskers in the Lac de Gras / Contwoyto Lake area were identified, counted and recorded on maps. Archaeological sites on eskers were documented in relation to various land attributes such as proximity to a water source. Wolf den locations were documented and analyzed in relation to esker characteristics. Wolf movements and habitat use among denning wolves were traced using satellite and radio collars.
Approximately 370 eskers in areas around Lac de Gras, Contwoyto Lake, Nose Lake, and west of Bathurst Inlet were identified. Of these, ten were not shown on existing maps of the area. The esker locations have been entered into a Geographic Information System (GIS), in cooperation with the Nunavut Planning Commission. Information gathered included percentage of eskers covered by vegetation, esker shapes and drainage patterns. Seventy-six granular samples were taken from eskers, analyzed and found to contain predominantly sand covered by stone and pebbles. Very little silt or clay was found. Within the study area, 150 heritage sites were located and 20 new heritage sites were identified: 44 of the sites were examined, documented and photographed. In general these sites were located at or near the top of the esker with a water source within 1000 metres (80% of sites visited were within 1000 metres of a water source and 64% were on eskers). Thirty-one percent of all archaeological sites in the region are on eskers.
All the wolf dens were found on or near eskers or other glacial features such as kames: most dens were found on smaller patches away from the main esker complexes, possibly because of greater vegetative cover and/or to be less visible to caribou using the eskers for travel. Caribou are a main source of food. Eighty-one active wolf dens, some not previously known, were mapped and entered into the digital database. Dens were found mainly in pebble pavement made up of sand and small stones. The dens are usually located where there is some vegetation such as birch, willow and grasses; this may be for cover and/or because roots provide structural support for the den.
Over the length of this project 58 wolves were collared, usually the dominant female in a pack, and mostly individuals from different packs. Use of collars allowed researchers to document large scale movements of individual wolves, and to check fidelity to denning sites.
In the winter of 1997-98, wolves traveled straight line distances of 300 to 600 km. following the Bathurst caribou as they moved south towards the Saskatchewan border. By May 1998, all but two of the collared wolves who survived the winter had returned to the same denning area used the previous year. During the denning period their movements are constrained, and this may explain the excursions that were observed; during the denning period, lactating females are forced to search large areas for prey but must return within a day or two: one female was found to cover 92 km. in less than 22 hours. The following winter some of the wolves traveled west to the area between Wekweti (Snare Lake) and Gameti (Rae Lakes), while others moved east of Great Slave Lake.
The data seem to support the idea that wolves return to natal denning areas, though not necessarily using exactly the same den. In 1998, two female wolves were found to use the same den, while two male wolves were found to have joined different packs in different denning areas more than a hundred kilometers distant. In 1999, all collared wolves returned to within 25 km. of their previous year's den, though the actual den sites could not always be found. Pup counts ranged from three to eight per den. Fewer wolf pups were seen at den sites in the summer/fall of 1999 compared to the previous year (3.1 pups/den in 1998; 4.6 pups/den in 1997).
Documented movements showed that average summer range size was 589 square km. for females and 2,273 square km. for males. A study of summer habitat preference showed the wolves prefer eskers over all other habitat types; likely because dens are associated with eskers.
Average winter range was much larger than summer range, 40,507 square km. for both sexes together. This is about 18 times the size of the average male summer range and almost 70 times the size of the average female summer range These results are similar to those for other wolves which rely on caribou as their main food source. Most other wolf studies have found they remain in fairly stable territories throughout the year, and rely on resident, rather than migratory, prey. It is not known whether the WKSS study wolves follow particular groups of caribou to their current wintering areas (which change year to year) or simply travel to areas where they will likely encounter caribou.
All satellite collars have been removed as they transmit for just one year, but since conventional VHF radio collars may continue to transmit for at least five years, they remain on some of the wolves to further monitor whether they repeatedly return to the same den sites.
Esker Habitat Characteristics and Traditional Use Study in the Slave Geological Province (2001)
Movements and Habitat Use of Wolves Denning in the Central Arctic, Northwest Territories and Nunavut, Canada (2002)