Northern red-backed voles (Myodes rutilus) are small creatures -- usually measuring 5 to 6 inches long -- that inhabit some of the northmost areas on the planet, including Alaska, Canada and Russia. Due to their size and the inhospitable environments in which they live, these voles have several useful adaptations to help them survive.
Northern red-backed voles feed on a diet of grasses, herbs, seeds, nuts, bark, fungus and insects. However, food can become scarce in the winter across their geographic range, leaving them with little to eat. As such, they've adapted to their environment by developing a drive to store as much food as possible during the summer and fall so they'll have ample supplies to keep them going during the colder months.
There are two distinct coat color morphs within the northern red-backed vole population: one is darker and almost reddish-brown in color, and the other is lighter and usually pale gray or even white. The dark morph is found in voles who live in boreal forest habitats, whereas the light morph is found in voles who live in the tundra. These different colorations are anti-predatory adaptations. The more they blend in with their environment, the less likely they are to end up as someone's dinner.
Another adaptation to reduce the impact of predators on northern red-backed voles is the areas in which they choose to live. They're drawn toward areas where there is plenty of ground cover, to offer them protection, such as thick moss or dense vegetation. A study at the Kenai National Wildlife Refuge showed that there was a positive correlation between numbers of these voles and the amount of protective ground cover. Regardless of whether there is abundant food elsewhere, these creatures will always go for the places where they're more sheltered and protected.
Northern red-backed voles are mostly crepuscular in their behavior, which means they're active during the twilight hours of dawn and dusk. However, most of their predators -- such as raptors, foxes, coyotes and weasels -- are either nocturnal or diurnal. By restricting most of their activity to hours when their predators aren't active, these small creatures have a better chance of surviving.
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