Wednesday, February 2, 2011

Deep Snow

The twenty inches of snow that fell across mid Missouri yesterday poses a significant hardship for human residents but may prove to be deadly for many of our wild neighbors. Some mammals, such as squirrels, cottontails, raccoons and opossums den up until conditions improve but, faced with persisent cold, will be forced to venture out within a few days; it is then that they risk detection by hungry coyotes, fox, owls and hawks. Small mammals, such as field mice and voles, are able to forage beneath the snow but they, too, are threatened by the highly developed senses of these predators.

Many flocking birds, such as geese, doves and longspurs, migrate south of the snow line while adaptable insectivores, such as chickadees, titmice and nuthatches, find sufficient nourishment from insect eggs and pupae in the the trees and shrubs. Ground feeding sparrows, towhees and juncos are especially vulnerable to heavy snow cover; some switch to a diet of berries while others scour dried grasses and thickets that project above the snow, consuming buds or residual seeds. For those birds and mammals that feed along open rivers and streams, such as bald eagles, great blue herons, gulls, otters and wintering ducks, the deep snow is of little consequence.

Finally, deer, while able to browse on shrubs and saplings, are hampered by reduced mobility, increasing their vulnerability to coyotes and feral dogs. Those that succumb to predation or starvation also provide nourishment for nature's many scavengers (vultures, crows, weasels, shrews) that rely on winter's victims to fuel their own survival.