Dall Sheep, Grizzly
Bear, and Wolf Capture Sessions
In April 2006, we fitted six Dall’s sheep ewes with Telonics TWS-3580 (GPS satellite) collars. The collared individuals belonged to different family groups, and were all located in the vicinity of Mount Goodenough (locally named Black Mountain). We then captured four wolves in each of the following areas: the Rat River valley and the Fish Creek valley, for a total of eight wolves. One wolf in each pack was equipped with a Telonics TWS-3580 collar, and the three others were fitted with Lotek 3300SW GPS collars (store-on-board models). Few months after the capture, we lost contact with one of the wolves wearing a GPS satellite collar, but we could retrieve and replace the collar in the 2007 session. In May 2006, seven grizzly bears (two males and five females) were fitted with Telonics TWS-3680 collars.
In 2007, we recaptured four of the wolves to equip them with new GPS satellite collars, and collared one additional wolf as well. We are now monitoring nine wolves from three different packs: the Rat River, Fish Creek, and Willow River packs, which cover most of the study area. We also equipped eight more grizzly bears with GPS satellite collars (3 males and 5 females). It was decided in collaboration with the local Renewable Resource Councils that no Dall sheep would be collared in 2007.
For all the marked animals except the wolves wearing store-on-board collars, partial locations are transmitted every week through the Argos system. The remaining locations will be obtained when we will retrieve the collars from the field, after they fall from the animals’ neck through a programmed release mechanism attached to each collar.
Mortality and Predation
Two of the sheep unfortunately died during the course of summer 2006, and their carcasses were retrieved at the bottom of a steep slope. The sites were visited too late after the collars have stopped moving, and the cause of the mortalities could not be detected. The signal from one grizzly bear has also stopped moving during the summer, relatively far outside the study area, and the collar will be retrieved soon. During our visits in the field in 2006, we discovered few sheep carcasses throughout the range, and one appeared to be a fresh predation case from wolves. Other carcasses were too old to provide information related to the mortality cause. Transects to find carcasses and investigations of kill sites are planned during our field sessions in June 2007 and 2008. The analysis of grizzly bear and wolf diets has not started yet, but we are actively collecting samples in collaboration with ENR, GNWT.
We are already noticing a large overlap between the three species range, particularly between grizzly bears and Dall sheep. The deployment of additional collars on the animals contribute to provide interesting insights about the interactions between the three species, and further monitoring will enable us to better understand their dynamics. I am currently in the process of analysing the available data and determining which spatial analyses will yield greater insights. At this time, techniques of choice will involve home range analysis, dynamic distances and movements of the individuals, resource selection, overlap between species and individuals, and multivariate statistics.
Snow and Climate Monitoring
A weather station was erected in the study area in August 2006, and it is programmed to record temperature, relative humidity, wind speed and direction, and barometric pressure at regular intervals of the day. Snow surveys were also performed in snowmobile in March 2006 by one team from Fort McPherson (Lloyd Nerysoo, Norm Vittrekwa and Shawn Vittrekwa), and one team from Aklavik (Ryan McLeod and Larry Koe). Snow depth and habitat characteristics were observed at different sites within the study area.
Traditional Knowledge Interviews
A Dall sheep local knowledge study was conducted in 2001 in Aklavik and Fort McPherson (Shaw et al. 2005), and more interviews with elders and knowlegeable users are planned for July and August 2007. The interviews will complement the knowledge acquired through other methods, and will document precious knowledge of Gwich'in and Inuvialuit elders and harvesters.