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Grizzly Bear numbers in southern BC, Alberta and northern Montana
I am a wildlife ecologist, former outfitter and rancher, living in Ta Ta Creek, B.C. I have watched the ongoing debate over grizzly bears in this part of the world for several decades, and, like many others, have tried to guess as to the actual number of grizzly bears that live in the mountains. Over the last decade biologists have developed and tested new tools to estimate bear numbers in Alberta, B.C. and northern Montana. I thought it would be useful to put these various estimates together to give people a perspective on the status of grizzly bears in this part of the world. Grizzly bears are now unique among the range of large mammals we have here. We now have credible estimates of grizzly bear populations for most of the Canadian Rockies and adjacent areas in Montana, using DNA analysis of hair samples to identify individual bears. Although highways and human habitation act, to some degree, as barriers to grizzly bear movement, it is important to remember that jurisdictional boundaries, i.e. the provincial boundary between Alberta and B.C., and the 49th parallel between the US and Canada are not a barrier to grizzly bears movement.
The southernmost population of grizzly bears (north of Yellowstone) is made up of bears along the east slope in Alberta, on the BC side in the Flathead valley and extending south through Glacier National Park and the Bob Marshall Wilderness in Montana. There are now over 1200 grizzlies in this population, as indicated below in Table 1.
Table 1. Grizzly bear population estimates for the Crown of the Continent area.
(between the south end of the Bob Marshall Wilderness area complex in Montana and Highway 3 (Pincher Creek to Fernie and Elko) in BC and Alberta)
Waterton Front to Crowsnest Pass 51
BC Flathead 175
Glacier Park Montana 500
Whitefish Range 200
South of Highway 2, Montana 300
*The numbers provided here come from work in Alberta (Status of the Grizzly Bear in Alberta: Update 2010), Montana (Mace et al 2011), Jasper and Banff National Parks (Boulanger et al. 2011) and BC (British Columbia Grizzly Bear Population Estimate for 2012).
The only major roads through this area are Going to the Sun Highway in Glacier Park and Highway 2 south of Glacier National Park, which are not considered a barrier to bear movement by biologists there, based on recent genetics work. There are several passes across the continental divide and it does not constitute a barrier to bear movement in this population. These numbers will come as a surprise to many people in Alberta, who tend to think about the bears on the Alberta side (51 animals) as an "endangered species". In fact, that population is part of a much larger population in BC and Montana.
The expansion of grizzly bear populations into ranchlands in southern Alberta and northern Montana is indicative of a very healthy population both in Alberta, Montana and in BC. One could argue that these populations are close to "carrying capacity", i.e. the ability of berry crops and other bear foods to support bears in this area. Bear densities in the BC Flathead were 40 bears/1000km2 in the 1970's when Bruce McLellan first started work there. Densities increased to 80/1000 km2 in the 1990's, then declined to 55/1000km2 today.
There is also data that suggests that populations in Glacier Park, Montana, are also in this range in terms of density. This is indicative of a bear population at or near the carrying capacity of the landscape. Bears are moving out onto the plains in the Waterton area, and along the face of the mountains in Montana, in part because all of the habitat in the mountains is occupied by bears and young bears have to wander into other areas to establish a territory. Density estimates for the east slope are lower than those found in the Flathead however the east slope is a much drier landscape than on our side of the divide, with fewer bear foods, so one should expect lower densities there, even at close to carrying capacity.
This population is, in turn, part of a much larger set of populations that are separated from this population by Highway 3 through Fernie and the Crow's Nest Pass. Though seen by some as "barriers" to bear movement, most bear biologists now see highways (without adjacent residential development as say, in the Canmore corridor), as "filters" rather than barriers. Male bears tend to move across highways and across major valleys; females have smaller home ranges and do so less often. The Crown of the Continent population is therefore part of a much larger population that stretches from the south end of the Bob Marshall Wilderness in Montana, to the Wilmore Wilderness on the east slope in Alberta and west through BC to the Okanogan Valley. There is a very recent paper by Mike Proctor and several other authors that looks in detail at the connections, or lack thereof, between these populations.
The Trench, i.e. the low elevation valley from Cranbrook north to Golden, was once considered a major barrier to bear movement, but it is less so now, in part due to very large kokanee salmon runs in the Kootenay and Upper Columbia Rivers that now attract bears into the main valley each fall. There are now grizzly bears, including female bears with cubs, resident in the valley in at least two places.
Highway 1 through Banff and into BC was considered in the past as barriers to bear movement. There is evidence that grizzly bears are using the highway under-passes in the Banff area and the populations to the north and south of that highway now have some degree of connection.
Table 2 indicates the population for this larger area.
Table 2. Grizzly bear populations in southern Canada and northern Montana.
Crown of the Continent 1226
Canadian Rockies 1309*
BC west of the Trench 1767*
* National Parks has developed estimates for Jasper and Banff National Parks. There are no estimates for bear populations in Yoho, Kootenay and Glacier National Parks in BC. A conservative estimate (100 for all three parks) would add 100 bears to the total of 4302 bears. The estimates on the BC side are based on Wildlife Branch data that used the various DNA based studies to identified bear numbers per unit of habitat and extrapolated to numbers in various management units, based on the extent of available habitat in each unit.
We have three inter-connected populations now, in the southern Rockies, each in excess of 1000 bears, which together make up a population of over 4300 bears. This population is, in turn, connected through large areas of wild country north of Valemont (which also supports a population of greater than 1000 bears), to the even larger populations in the remainder of northern BC. The total population for BC is estimated at more than 15,000 bears.
The problems faced by grizzly bears and grizzly bear managers are fundamentally different now from what they were 30 years ago. These estimates of bear population numbers and densities are indicative of a healthy, robust and a relatively high density population; not a population at risk. There is no hunting harvest in Alberta, or Montana, and minimal harvest in BC. Harvest by hunters in BC is based on a 6% annual mortality target, including problem bears killed by Conservation Officers, mortality on roads and railways, etc. Hunting results in about a third of this mortality.
The only area where grizzly numbers are likely significantly below carrying capacity are in the areas south of Highway 3 between Cranbrook and Creston, including the Yahk River drainage in northern Montana, and in the Selkirks south of Highway 3 between Creston and Salmo, including portions on the US side.
As a young biologist I worked for the Alberta Fish and Wildlife Department doing wildlife surveys in the Kananaskis area (circa 1969). At that time when we found a grizzly bear track, it was the subject of coffee table discussions for weeks. Grizzly bear populations were very low in those days and those populations were likely "at risk". The situation in those days was similar in southern BC and Montana. However to suggest that they are "at risk" today, is to ignore fundamental facts relating to the present population. We have collectively done a hell of a job and grizzly bears have recovered across their range in our part of the world. This is a major accomplishment.
This means however, that the management problems associated with grizzly bears in 2013 have fundamentally changed. In the past the challenge was how to recover grizzly bear populations. That task in now complete. The challenge now is how do we manage a large and robust grizzly bear population when large numbers of people still think that bears are at risk and do not want to see them hunted or killed. The issue in Alberta and Montana are around how we manage bears as they expand into agricultural land on the plains. National Parks have to deal with risks to visitors on a scale that did not occur in previous decades. The result in the closure of many areas each year, to minimize risks to people and bears. In BC, grizzly bears are coming to elk carcasses within hours of a hunter killing of an elk. Each fall there have been several instances where hunters have had to abandon their hunting camps due to grizzly bears. We now face a serious human safety issue around this issue. Most people here are willing to accept that risk as part of the hunting experience and it involves people who are armed. The safety issues arising as more bears are living much of the year in human occupied areas in the Trench; is a very different issue. We now have to make some difficult decisions in all of these areas concerning exactly how many bears is enough to meet conservation concerns in the long term on one hand, and address public safety and nuisance bear issues on the other. This will not be an easy task, given declining budgets for the Wildlife Branch and the cost of effective monitoring of bear populations.
Status of the Grizzly Bear in Alberta: Update 2010. Status report No. 37, Feb. 2010.
Boulanger, J., S. Nielson, J. Cranston and G. Stenhouse, 2011. Estimation of grizzly bear population size for Jasper and Banff National Parks using DNA sampling and habitat-relative occupancy models. For Parks Canada.
British Columbia Grizzly Bear Population Estimate for 2012. Ministry of Forests, Lands and Natural Resource Operations, April, 2012.
Mace, R. et al. 2011. Grizzly Bear population vital rates in the Northern Continental Divide Ecosystem, Montana. J. of Wildl. Mgnt 999:1-10.
Proctor et al. 2012. Population Fragmentation and Inter-Ecosystem Movements of Grizzly Bears in Western Canada and the Northern United States. Wildlife Monographs 180:1–46; 2012.