December 19th, 2013 by

Yesterday I wrote about the alarming decline of moose populations in the Northeast, especially in Vermont and New Hampshire. There, though many factors may be at play, winter ticks seem to be a primary culprit.

But the Northeast is not alone in watching their moose populations decline. It’s been happening across North America, though the causes differ from area to area…or do they?

Moose and calf in British Columbia.

Moose and calf in British Columbia. Credit: Arthur Chapman

In British Columbia, a report from Wildlife Infometrics Inc commissioned by the provincial government has laid a lot of the blame for the declining moose population on another tiny terror: the mountain pine beetle. The current epidemic of these beetles throughout much of the Mountain West has decimated forests of whitebark and lodgepole pine. The loss of lodgepole forests in the Caribou Mountains has deprived moose of their vital forest cover leaving them more exposed to predators and unregulated hunting, while the clearing of much of the dead lodgepole has led to the creation of more logging roads, bringing even more unregulated hunting into the area.

But are these causes really so different? These ecosystems both have natural defenses against these little critters. The real culprit here is what lies behind the sudden inability of those defenses to keep up with these threats: climate change. While the winter tick in the Northeast is surviving at a higher rate due to a decrease in snow cover, the mountain pine beetle population is soaring out of control largely due to warmer winters.

In fact, the beetle is even populating areas that were previously too cold for it — high elevation whitebark pine forests in places like the Greater Yellowstone Area, where American Forests is working to combat it. We’ve been working with volunteers to attach pheromone patches to certain whitebark pine trees to repel the beetles.

The mountain pine beetle epidemic is affecting so many species in these areas, from grizzlies to Clark’s nutcrackers. Add moose to the list.