The West/Central Chilcotin region provides interior grizzly bears with precious spring habitat and potential access to the coast. Due to its large expanses of inaccessible wilderness, only little human impact and the fact that the third largest salmon run in BC occurs there, the region is home to one of the wildest populations of grizzly bears in Southern Canada and the US. However, very little scientific information such as population numbers, movements, and critical habitats on the species is available.
Large-scale wilderness areas such as the West/Central Chilcotin can be essential for the long-term survival of historic, wide-ranging animals like the grizzly bear. Unlike many other grizzly areas like Banff, Jasper, Kootenay and Yoho National Parks, the region is not as affected by human impact. Nevertheless, there are threats for local grizzly populations such as declining salmon populations due to global warming, water runoff caused by pine beetle devastation and anthropological threats like advanced settlement, logging, mining, backcountry cattle range use and recreation, resulting in road building and habitat alteration.
In order to get a better documentation of grizzlies in the West/Central Chilcotin and their needs within the area, the Nature Conservancy of Canada implemented DNA sampling and evaluating between 2006 and 2008. Because of recent developments in genetic technology, hair samples allow identification of species, sex, and individuals. Bear hair was systematically collected by positioning barbed wire hair traps.
During the process, 133 distinguished grizzly bears were identified in two sampling areas in spring and salmon run in fall. In spring, 54 individuals were detected in the Tatlayoko Valley in during fall, 106 grizzlies were identified on the upper Chilko River, whereas 26 of the bears in Tatlayoko Valley were also sampled along the Chilko River.
The results of the study showed that the Tatlayoko Valley offers early green-up rich habitat during spring, which attracts many grizzly bears from areas that can’t supply such high quality ranges. As grizzlies rather move to higher elevations in summer, and to richer food source areas such as salmon streams in fall, the density estimated for the valley may only be applied to the spring season.
On the other hand, the Chilko River is very appealing during fall, as it serves as a salmon stream, which draws grizzly bears from far away. Studies showed that two males even travelled over 115 km from near Gold Bridge to the stream. Assuming that these 115 km are the possible radius for bears to travel to their fall range, the Chilko River may be a critical food source for bears within an area of 41,000 square kilometres. This estimation shows the importance of salmon streams to bear habitat.
Grizzly bears’ future depends on the quality of their habitat, the amount of people within or near the habitats, as well as their behaviour. That’s why further research is required to get a deeper insight into the habits of grizzlies so that humans can adapt to the bears’ requirements in order to ensure a healthy coexistence.
- Source Cedar Mueller. November 2009. Grizzly bears in the Tatlayoko Valley and along the upper Chilko River: Population estimates and movements Final Report. Prepared by Osa Ecological Consulting, for Nature Conservancy of Canada. 39 p. Available at : https://www.natureconservancy.ca/assets/documents/bc/tatlayoko/Grizzly_Bears_in_the_Tatlayoko_Valley_2009.pdf [Accessed 03/2021].