Kangaroo

 
Kangaroos are the largest living marsupials from the family Macropodidae. There are four species commonly referred to as the kangaroo: the red kangaroo, the eastern grey kangaroo, the western grey kangaroo, and the antilopine kangaroo.Kangaroos are grazing herbivores, which means their diet consists mainly of grasses. They can survive long periods without water.Kangaroos are found in Australia and Tasmania, as well as on surrounding islands. Kangaroos live in varied habitats, from forests and woodland areas to grassy plains and savannas. 
Kangaroos live and travel in organized groups or "mobs," dominated by the largest male. Male kangaroos are called boomers, bucks or jacks; females are does, flyers, or jills, and the young ones are joeys. The collective noun for kangaroos is a mob, troop or court.

Kangaroos are the only large animals to use hopping as a means of locomotion. The comfortable hopping speed for a red kangaroo is about 20–25 km/h (13–16 mph), but speeds of up to 70 km/h (44 mph) can be attained over short distances, while it can sustain a speed of 40 km/h (25 mph) for nearly 2 km (1.2 mi). This fast and energy-efficient method of travel has evolved because of the need to regularly cover large distances in search of food and water, rather than the need to escape predators. At slow speeds, it employs pentapedal locomotion, using its tail to form a tripod with its two forelimbs while bringing its hind feet forward. Kangaroos are adept swimmers, and often flee into waterways if threatened by a predator. If pursued into the water, a kangaroo may use its forepaws to hold the predator underwater so as to drown it. 

Because of its long feet, a kangaroo cannot walk normally.To move at slow speeds, a kangaroo will use its tail to form a tripod with its two forelimbs. It then raises its hind feet forward, in a form of locomotion called "crawl-walking."Usually, female kangaroos give birth to one joey at a time. Newborns weigh as little as 0.03 ounces at birth - as small as a lima bean! After birth, the joey crawls into its mother's pouch, where it will nurse and continue to grow and develop. Red kangaroo joeys do not leave the pouch for good until they are more than eight months old. Gray kangaroo joeys wait until they are almost a year old.