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Behaviour at the 50th berry day

By Michael Allen Bear Researcher On the 50th day (Aug. 11-Sept. 30) of high elevation (> 1,400-metres) berry feeding, ski area bears have consumed about 80 per cent of the huckleberry, blueberry, and Sitka mountain ash crop.

By Michael Allen

Bear Researcher

On the 50th day (Aug. 11-Sept. 30) of high elevation (> 1,400-metres) berry feeding, ski area bears have consumed about 80 per cent of the huckleberry, blueberry, and Sitka mountain ash crop.

Mountain ash berries were better this year than in 2005. The 2005 crop was poor, due likely to the low snowpack in 2004-05 where shrub tips were exposed and damaged during winter.

Mountain ash is important as the secondary berry for bears after major huckleberry/blueberry feeding ends in mid-late September. Bears are currently foraging mountain ash high into the subalpine and searching through scattered patches of "light" huckleberry/blueberry.

Berry foraging strategies are different throughout the total berry period, from July to October. At the start, bears do not search for every single berry, instead they skim through the patches eating the obvious ripe berries that are easiest to see (bears can see colour) and take little effort to consume. Bears consume berries by using their loose lips and tongues and slurping the berry from the stem.

By "high grading" a berry patch, bears do not waste time "searching" the entire shrub for partially ripe berries. Their strategy is to skim the shrub for obvious ripe berries every pass through the patch. When berry availability peaks and more ripe berries are "presented" to bears, bears will spend more time foraging in each patch. As berry abundance falls, bears then revert to more detailed searching of every shrub. This takes more time because by mid-September berries begin to shrink in size, making them harder to see.

Late season berries are less juicy but higher in sugar.

Bears also have different strategies for foraging berry-patch locations. These strategies differ between sexes and age class and thus, each bear's status in the hierarchy of the population. Generally, bears seem to adopt the approach that it is better to feed on small amounts of berries in several different patches than to feed on all the berries in fewer patches. The underlying principle of this strategy, I think, is that bears gain better knowledge of berry abundance and location over a greater area. Bears always need to have alternatives in case (as always seems to be the case) berries do not ripen equally in every patch.

Resident bears and bears higher in the hierarchy have the most consistent access to berry patches. For example, Whistler Mountain's most concentrated berry patches occur on the north slope between the gondola and the Harmony chair.

During the peak berry period from August to September, only three sub-adult male bears were identified in this area during 852 sightings of 36 known animals (previously identified), the bulk of the bear-class were resident females (with and without cubs), maturing daughters, and three large males.

Sub-adult bears, particularity males, have the least success in accessing prime berry habitats and are often pushed to lower quality patches (in Fitzsimmons Valley and Blackcomb) where berries are more scattered than concentrated. This has been the trend on Whistler Mountain since 1996, when I began monitoring bear behaviour and abundance in enhanced, clumped food sources.

Sons, because they are forced to disperse from their natal range, are limited to lower quality natural habitats and/or vulnerable to selecting higher quality non-natural or developed habitats in Whistler valley. Although I am not involved in the government assessment and research of bears in Whistler, I have observed for the past 13 years that sub-adult males and maturing males are poorly represented in berry patch census.

So be prepared for an increase in bear activity from mid-October to mid-November in Whistler valley as the younger bears that did not gain access to berry patches try to supplement their needed weight gain with human foods.

Eight bears have died in Whistler so far this year, so this may alleviate some of the usually higher sub-adult activity typically experienced in fall.

Looking at the bigger picture of the 2006-07 population forecast, a minimum of 12 females have 24 cubs this fall. That translates to 24 yearling (1.5 years old) bears next spring with likely more than half as teenage males being pushed out of better habitats. Regardless of whether a mother teaches her offspring to search for and consume human food, those sub-adult males will ultimately be struggling to fulfill their basic biological need to survive and compete with larger bears.

That means younger bears need food — food they cannot get in higher quality habitats. Our message to this young generation of males is that it should be very difficult to access human foods in residential areas and the village and that these young males need to be pushed back into marginal habitats where they naturally go through the process of dispersal, which could take them 50-100 km from Whistler.

To do this, a consistent level of strategic bear proof garbage containment is needed throughout valley environs over a long period.

Special thanks to Arthur DeJong at Whistler-Blackcomb for maintaining the highly successful ski area bear viewing program that allows for visitors and locals to experience one of the most effective forms of bear education and that allows the systematic monitoring of bear use in ski area berry patches.