Gray kangaroos roam the forests of Australia and Tasmania and prefer to live among the trees, though they do take to open grasslands for grazing.
Gray kangaroos, red kangaroos, and wallaroos are called the great kangaroos because they are so much larger than the nearly 70 other kinds of kangaroos.
Gray kangaroos hop along on their powerful hind legs and do so at great speed. A gray kangaroo can reach speeds of over 35 miles (56 kilometers) an hour and travel for long distances at 15 miles (24 kilometers) an hour. Their bounding gate allows them to cover 25 feet (8 meters) in a single leap and to jump 6 feet (1.8 meters) high.
Females have one baby at a time, which at birth is smaller than a cherry. The infant immediately climbs into its mother's pouch and does not emerge for two months. Until they reach about 10 or 11 months of age, threatened young kangaroos, called joeys, will quickly dive for the safety of mom's pouch. As they grow, joeys' heads and feet can often be seen hanging out of the pouch.
Larger male kangaroos are powerfully built. Like many species, male kangaroos sometimes fight over potential mates. They often lean back on their sturdy tail and "box" each other with their strong hind legs. Kangaroos can also bite and wield sharp claws, which they may do in battle with an enemy, such as a dingo.
Gray kangaroos gather in groups called "mobs." Aboriginal and European Australians have spent centuries clearing open tracts of land and establishing water sources—both of which are boons to kangaroo populations. Many millions of these animals roam Australia, and considerable numbers are killed each year for their skins and meat, which is becoming a more popular human food.