Overview
The Montane Vole (Microtus montanus) is a compact, industrious microtine rodent that forms the vital energetic foundation of western North American mountain ecosystems. Inhabiting lush alpine meadows, high-elevation river valleys, and grassy mountain parks, this prolific herbivore constructs intricate labyrinthine surface runways through dense meadow grasses, sustaining predators ranging from owls and hawks to coyotes, foxes, and weasels.
Biology and Physical Characteristics
Microtus montanus has a stocky, cylindrical body with short legs and a relatively short, bicolored tail that is less than one-third of its total body length. Its dense, plush fur ranges from grizzled brownish-grey to dark ochre on the back, washed with silvery-grey underneath. Its ears are small and almost completely concealed within the thick fur, and its blunt snout is framed by sensitive facial vibrissae.
Behavior and Ecology
Active year-round day and night, the Montane Vole clips green grass stems and sedges to maintain clean, unobstructed surface runways beneath overhanging vegetation. During harsh mountain winters, it lives subnivean lives in the warm, insulated space between the snowpack and the ground, tunneling through snow to feed on cached seed stores and plant crowns without ever emerging into freezing winter blizzards.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, the Montane Vole is abundant and widespread throughout western mountain cordilleras. Populations undergo cyclical multi-year population surges and crashes that directly dictate the breeding success and population densities of montane raptors, particularly boreal owls and northern harriers.
Interesting Factoid
During heavy mountain winters, Montane Voles never hibernate: they live in a cozy subnivean wonderland beneath six feet of insulating snow, constructing miles of snow tunnels and grass nests while temperatures above drop to 30 degrees below zero.