Moose are so tall that they prefer to browse higher grasses and shrubs because lowering their heads to ground level can be difficult. In winter they eat shrubs and pinecones, but they also scrape snow with their large hooves to clear areas for browsing on mosses and lichens. These hooves also act as snowshoes to support the heavy animals in soft snow and in muddy or marshy ground.
In summer, food is far more plentiful in the northern regions of North America, Europe, and Asia. When the ice melts, moose are often seen in lakes, rivers, or wetlands, feeding on aquatic plants both at and below the surface. Moose are at home in the water and, despite their staggering bulk, are good swimmers. They have been seen paddling several miles at a time, and will even submerge completely, staying under for 30 seconds or more. Moose are similarly nimble on land. They can run up to 35 miles (56 kilometers) an hour over short distances, and trot steadily at 20 miles (32 kilometers) an hour.
Males, called bulls, bellow loudly to attract mates each September and October. The usually solitary bulls may come together at this time to battle with their antlers for mating supremacy. After mating, the two sexes go their separate ways until the following year. Though they may occasionally feed in the same grounds, they tend to ignore each other.
Females give birth to one or two calves in the spring—each weighing some 30 pounds (14 kilograms). These calves grow quickly and can outrun a person by the time they are just five days old. Young moose stay with their mothers until the following mating season.