If you have been roaming up in the mountains this summer, you probably heard “the whistler” or hoary marmot (Marmota caligata), also known as whistle pigs. The marmot’s piercing whistle is a warning to its buddies that there is potential danger in the area (you included) so they can be prepared. Whistler Mountain is named after them.
Hoary marmots range through western North America from southern Idaho and Washington north through BC to Alaska and the Yukon. They inhabit mainly rocky alpine areas or subalpine meadows with lots of grasses, sedges, herbs and patches of krummholtz.
Burrows can often be seen from a distance because they are often surrounded by lush, tall grasses that are much greener due to nitrogen fertilization from urine and droppings.
Hoary marmots are bulky rodents with silvery-gray hair covering their shoulders and upper back (hence hoary) and drab brownish or reddish-brown fur over the rest of the upper body.
They have a whitish muzzle, and their lower legs and feet are blackish (caligata means booted). The colouring camouflages them against rock-covered slopes.
The front paws especially are equipped with strong, slightly curved claws for digging deep burrows in which they hibernate over winter and shelter from mosquitoes during calm days.
They need a bit of breeze to be able to survive mosquitoes, so are often more active outside the burrows in the mornings and evenings. They mark their territories by rubbing their faces and glands on rocks and trails.
Hoary marmots are quite personable. On my very first hike on the Hudson Bay Mountain prairie in the 1970s, marmots lined the narrow trail. At one spot the marmots were so curious about us we were able to get down on hands and knees and almost rub noses with one (phew, they are smelly!).
Unfortunately, when people started letting their dogs run loose on the prairie, the marmots soon vacated the area. Quite a few are now denning over near the new mountain bike trail which could mean they will move on yet again.
Research in the northwestern U.S. suggests hoary marmot numbers are declining, and this could be related to climate change.
An early spring and snowmelt results in lush forage being available longer for the mothers weaning pups. Hence, pups go into the den in better condition to survive the winter hibernation.
Both late spring and short summers, as well as, long, hot, dry summers means less or poorer quality forage with fewer pups surviving hibernation.
Overall, data suggest numbers are in decline.
