April 14, 2008

nd once again is snowing this morning. It is a good snowstorm, but not sticking. With the winds, my driveway is drying out and there is only half the snow amount that there was. 

I worked all weekend and in my travels, for the second time since I moved to Canada, I was privileged to be able to see a small herd of Mountain Cariboo.

The three cows and two calves were standing in the middle of the roadway before going over the side of the road to walk across the lake. These animals are considered one of the most endangered mammals in North America. The globally unique mountain caribou is a variety of Woodland Caribou that has adapted to the special conditions of British Columbia's wet, mountainous forests. Census results from 2004 show declines of 50% over the past decade among the herds of Mountain Caribou across the southern portion of their range.

Mountain Caribou migrate up and down the mountainsides, from the valley floors in spring and fall to the high forests in winter and summer. In winter when their other food is buried they stand on top of the snow, using their large snowshoe feet, and eat the lichens that grow on old-growth trees. 

They require unbroken tracts of old-growth forest for food and for security from predators. Because of this dependency, mountain caribou are considered indicators of the ecological integrity of these old-growth forests. Their numbers have been steadily declining, from approximately 2,200 in the late 1990's to approximately 1,900 today, mostly due to human-caused habitat changes. What may have once been one large Mountain Caribou population has been fragmented into as many as 18 subpopulations with little or no interaction. Smaller, disconnected populations are more prone to extinction.

As the snowpack deepens, digging for food uses more energy than is gained. Caribou move upslope in midwinter, unlike any other ungulate, seeking lichens (principally Alectoria, Bryoria) that grow on trees.

Lichens grow slowly. For there to be sufficient amounts of accessible lichen, caribou need old trees. The combination of winter storms and snow laden branches result in lichen blown off of trees or entire trees blowing over, providing caribou a feeding opportunity. This is more likely to happen in an old growth stand where the trees are rotten enough to fall over or the branches to snap off.

By March, caribou are in the sub-alpine forest in places like the summit of mountains where a three or four metre snowpack is typical. Though not much bigger than deer, caribou have feet as large as moose and are able to spread their hooves and dew claws to act as small snowshoes. The deep snowpack lifts caribou to lichens on the trees they could not otherwise reach. Lichens alone maintain caribou through the last part of the winter.

In spring, as soon as plants green up at low elevations, caribou head down to the valley bottoms for something fresh to eat, returning to the alpine meadows again for the summer. To avoid predators, pregnant cows return to higher elevations earlier than males to calve individually in remote locations.

I also attended another event for work this weekend and I was really excited to see the 'silverware' almost more than seeing my breakfast at the event. I completely forgot about my pancakes for a bit as I admired the eating utensils. They are usually made from aspen or birch and they are completely wooden spoons, forks and knives. Help preserve the environment by using eco-friendly wooden disposable cutlery. If you are having an event, make sure to get these. They look good and are much more effective than plastic while being harvested from re-planted forests. The knives come with a serrated edge for extra effectiveness and I thought worked better than plastic anyway.