One of the animal kingdom’s most industrious mammals is the beaver. Growing to a length of 50 centimeters (20 inches) and tipping the scales at around 20 kilograms (44 pounds), it has a flat, rudderlike tail and webbed back feet that enable it to swim at speeds up to 10 kph (6 mph). The exploration of western Canada can be directly attributed to the beaver, whose pelt was in high demand in fashion-conscious Europe in the early 1800s. The beaver was never entirely wiped out from the mountains, and today the animals can be found in almost any forested valley with flowing water. Beavers build their dam walls and lodges of twigs, branches, sticks of felled trees, and mud. They eat the bark and smaller twigs of deciduous plants and store branches under water, near the lodge, as a winter food supply.
Several species of squirrel are common in the Canadian Rockies. The golden-mantled ground squirrel, found in rocky outcrops of subalpine and alpine regions, has black stripes along its sides and looks like an oversized chipmunk. Most common is the Columbian ground squirrel, which lives in burrows, often in open grassland. It is recognizable by its reddish legs, face, and underside, and a flecked, grayish back. The bushy-tailed red squirrel, the bold chatterbox of the forest, leaves telltale shelled cones at the base of conifers. Another member of the species, the nocturnal northern flying fox, glides through the montane forests of mountain valleys but is rarely seen.
High in the mountains, above the tree line, hoary marmots are often seen sunning themselves on boulders in rocky areas or meadows. They are stocky creatures, weighing 4–9 kilograms (9–19 pounds). When danger approaches, these large rodents emit a shrill whistle to warn their colony. Marmots are active only for a few months each summer, spending up to nine months a year in hibernation.
This small, squat animal is easily recognized by its thick coat of quills. It eats roots and leaves but is also known as being destructive around wooden buildings and vehicle tires. Porcupines are common and widespread throughout all forested areas, but they’re hard to spy because they feed most often at night.
Widespread throughout western Canada, muskrats make their mountain home in the waterways and wetlands of all low-lying valleys. They are agile swimmers, able to stay submerged for up to 12 minutes. They grow to a length of 35 centimeters (18 inches), but the best form of identification is the tail, which is black, flat, and scaly. Closely related to muskrats are voles, which are often mistaken for mice. They inhabit grassed areas of most valley floors.
A member of the insectivore family, the furry shrew has a sharp-pointed snout and is closely related to the mole. It must eat almost constantly because it is susceptible to starvation within only a few hours of its last meal. Another variety present throughout the region, the pygmy shrew, is the world’s smallest mammal; it weighs just four grams (0.1 oz.).
Pikas, like rabbits, are lagomorphs, which are distinguished from rodents by a double set of incisors in the upper jaw. The small, grayish pika is a neighbor to the marmot, living among the rubble and boulders of scree slopes above timberline.
The weasel family, comprising 70 species worldwide, is large and diverse, but in general, all members have long, slim bodies and short legs, and all are carnivorous and voracious eaters, consuming up to one-third of their body weight each day. Many species can be found in the Canadian Rockies, including the wolverine, largest of the weasels worldwide, weighing up to 20 kilograms (44 pounds). Known to natives as carcajou (evil one), the wolverine is extremely powerful, cunning, and cautious. This solitary creature inhabits forests of the subalpine and lower alpine regions, feeding on any available meat, from small rodents to the carcasses of larger mammals. Rarely sighted by humans, the wolverine is a true symbol of the wilderness.
The fisher has the same habitat as the wolverine but is much smaller, reaching just five kilograms (11 pounds) in weight and growing up to 60 centimeters (24 inches) in length. This nocturnal hunter preys on small birds and rodents, but reports of fishers bringing down small deer have been made. Smaller still is the marten, which lives most of its life in the trees of the subalpine forest, preying on birds, squirrels, mice, and voles. Weighing just one kilogram (2.2 pounds) is the mink, once highly prized for its fur. At home in or out of water, it feeds on muskrats, mice, voles, and fish. Mink numbers in the Canadian Rockies are low.
As well as being home to the largest member of the weasel family, the region also holds the smallest—the least weasel (the world’s smallest carnivore), which grows to a length of just 20 centimeters (8 inches) and weighs a maximum of 60 grams (2 oz.). Chiefly nocturnal, it feeds mostly on mice and lives throughout open wooded areas, but it is not particularly common.
© Andrew Hempstead, from Moon Western Canada, 3rd Edition