BACKGROUND - Canadian Rockies: Including Banff and Jasper National Parks - page 512

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 ounces). Chiefly
nocturnal, it feeds mostly on mice and lives throughout open wooded areas, but it is not
particularly common.
REPTILES AND AMPHIBIANS
Two species of snake, the wandering garter snake and the red-sided garter snake (North
America's northernmost reptile), are found at lower elevations in the Canadian Rockies.
Frogs are also present; biologists have noted two different species, which are also present
at the lower elevations in the Canadian Rockies.
FISH
The lakes and rivers of the Canadian Rockies hold a variety of fish, most of which belong
to the trout and salmon family and are classed as coldwater species—that is, they inhab-
it waters where the temperature ranges 4-18°C (39-64°F). The predominant species, the
rainbow trout, is not native to the mountains; it was introduced from more northern Cana-
dian watersheds as a sport fish and is now common throughout lower-elevation lakes and
rivers. It has an olive green back and a red strip running along the center of its body. Only
three species of trout are native to the mountains. One of these, the bull trout, is Alberta's
provincial fish. Throughout the mid-1900s, this truly native Canadian trout was perceived
as a predator of more favored introduced species and was mostly removed. Today, what
was once the most widespread trout east of the Continental Divide is confined to the head-
waters of the Canadian Rockies' river systems and is classed as a threatened species. While
the bull trout has adapted to the harsh conditions of its reduced habitat, its continuing
struggle for survival can be attributed to many factors, including a scarcity of food and a
slow reproductive cycle. Bull trout grow to 70 centimeters (27 inches) in length and weigh
up to 10 kilograms (22 pounds).
The lake trout, which grows to 20 kilograms (44 pounds), is native to large, deep lakes
throughout the mountains. Identified by a silvery gray body and irregular white splotches
along its back, this species grows slowly, taking up to 8 years to reach maturity and living