A kangaroo is an animal found only in Australia, although it has a smaller relative, called a wallaby, which lives on the Australian island of Tasmania and also in New Guinea. Kangaroos eat grass and plants. They have short front legs, but very long, and very strong back legs and a tail. These are used for sitting up and for jumping. Kangaroos have been known to make forward jumps of over eight metres, and leap across fences more than three metres high. They can also run at speeds of over 45 kilometres per hour.