Bear Update 

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.

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.


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