The snowy owl, a quick-flying predator with excellent eyesight, lives in the arctic year round. Because the snowy owl likes to eat ground-dwelling animals such as lemmings, he usually builds his nest in the snowy ground. A snowy owl chooses a favorite perch and spends hours at a time on this perch, swooping down from time to time to catch prey. Before a male and a female snow owl pair up for mating, the male brings the female a gift -- lemmings.
The Norwegian lemming is a productive rodent; a female can produce a litter of 12 young every month of the year, although the lemming's reproductive ability diminishes automatically when food supply is short. Lemmings live far above sea level on the flat lands of the tundra. In the summer, they build nests under rocks or fallen trees, digging a short tunnel and a small nesting hole and lining them with grass for comfort. But in the winter, lemmings nest directly on the ground underneath the snow; they build round nests of dry grass and line them with moss and lichen.
Black bears are large mammals with bodies that are highly adapted to cold temperatures, such as those found in northern Minnesota where many black bears live. During the winter months, black bears hibernate for long periods of time uninterrupted. They are able to maintain a much higher body temperature than other hibernating animals; as a result, 99 percent of black bears survive the cold winter, which is a very good percentage compared to other animals that are forced to face the ravages of winter. Black bears can nest directly on the ground with very little insulation around them.
Snow buntings are small, beautiful birds with mostly white plumage and black features on their wings and tails. They travel in large flocks that often number hundreds, and sometimes thousands, of birds. Buntings feed mostly on seeds during the winter, while during the summer, they eat more insects and spiders. Birds in coastal areas eat small crustaceans as well. Female snow buntings build thick-walled nests out of roots, grass and moss, lining it with feathers and hair. The nests can be located in the snow on short prairie grass; but, when possible, the birds prefer to find a protected rock crevice for increased safety during nesting. In the nest, the female incubates three to nine eggs for a couple of weeks before the little birds hatch. After they hatch, male and female birds both take turns bringing food to the baby birds.