Bear Update: Arrival of summer's berries By Michael Allen Black Bear Researcher Steep slopes and hot weather are not a good combination. I sat down and dug the heels of my hiking boots into the grassy slope of Freefall, one of the steeper ski trails on Blackcomb. It was 33 degrees Celsius and the bugs were fine dining on my legs. You would think I'd be used to these conditions after almost 20 years of following black bears around in the bush. The bugs yes, somewhat — but never the heat. Downslope about 20 metres, grazing at the ski trail's edge, was Blackcomb's dominant alpha male — a reddish-brown phase 250-300 lb. adult black bear with a large white V on his chest. He is close to the weight at which he emerged from his den in early April because he has yet to fatten on berries. He moved into the deciduous shrub over along the edge and slumped down between two clumps of willow. Along these ski trail edges the temperature is as much as 5 degrees cooler. Run-off creeks are often present and bears cool by wading and drinking. I could hear his heavy panting and shallow breathing. I wondered if he knew it was cooler to be brown than black. Nevertheless, he too was heat-stressed. Above 25 degrees Celsius, I’ve found bears become heat-stressed. The black and dark brown coats of bears do not reflect heat from direct sunshine. Bears usually avoid open areas like cutblocks (logged areas) and ski trails during hot sunny days. Feeding activities are confined to the cooler, early mornings and evenings. Symptoms of heat stress in bears include heavy panting (similar to a dog's cooling mechanism) and foaming at the mouth. Since July 5, we have had increasingly sunny and warm weather. Oval-leafed blueberries (Vaccinium ovalifolium) and black huckleberries (Vaccinium membranaceum) are ripening along the Whistler Valley floor. Bears have been observed feeding on berries near the landfill, along the Cheakamus River, around Nita Lake and at the base of Blackcomb. Although ripe, some berries are smaller this year than last and many shrubs have failed completely due to temperature extremes this spring. Alaskan blueberry (Vaccinium alaskanese), a huckleberry characteristic of Blackcomb and Whistler Mountains, and red huckleberry (Vaccinium parvifolium), one of the most widespread huckleberries in the valley, have yet to ripen. This year’s berry crop is ripening almost a month later than 1995’s, when the first huckleberries ripened in mid-June. So far, cub survival is 100 per cent in my 15-cub observation sample. However, two cubs were found on their own. One cub is from a litter of three and I have yet to determine if he is abandoned or temporarily separated from his mother. The other cub was observed for two days on her own before she caught up to her mother. Both healthy cubs actively fed on vegetation and huckleberries while away from their mothers. A reminder to anyone who sees a seemingly abandoned cub: you are not increasing the bear's survival by picking it up. The most common reason for cub separation is that the mother is driven from her area suddenly and severely. Adult male bears and human intrusion are the primary cause for this. Cubs are usually too small and scared to keep up with their retreating mother. Given time and no further danger in the area the mother bear will usually locate her cub. The first berry-ripening areas will be the valley floor and the lower mountain forest openings on south and south-west aspects. Not all bears feed on berries right away. If a bear's familiar areas or home range are located above the current berry ripening area they will periodically investigate "learned" potential berry habitats. Some bears are still grazing on the new grasses and clovers on high elevation ski trails. Bears tend not to feed exclusively at one berry site, but rather feed in small amounts in several different patches so they can learn and map out a wider range of berry crops in case of failure or delay of berries at specific patches. Black bears also rely on berries which ripen later than huckleberries. Purple Saskatoon or Seviceberries (Amerlanchier alnifolia) are abundant in hot, disturbed habitats along the Westside road and adjacent transmission line corridors. Saskatoons are still not ripe and currently look like little green apples in an upright shrub 1-5 metres tall. Sitka mountain ash (Sorbus sitchensis) are extremely bitter (to our taste) orange to pinkish-red berries in large clusters. Their shrubs are 1-4 metres tall. Berries are most abundant and productive in forest openings and shrub-dominated habitats. If you live near such areas you should learn to identify bear food shrubs — get a B.C. plant guide from the library. When the berries ripen you can expect bears to come to feed, even if the shrubs are next to your house, because of the shortage of berry crops this year. Michael Allen can be heard on Mountain FM’s Mountain Monitor program the fourth Tuesday of each month. Listen July 23 at noon.
