Why do kangaroos have long legs but not long arms?

Answer 1

Kangaroos do not need long forlimbs. Their "arms" and claws are used for grasping hold of food. When walking, kangaroos support themselves with their front legs and tail while they pull their hind legs along. Apart from that, their usual method of locomotion is hopping and bounding, and their short forelimbs are not required for that.

Answer 2

Kangaroos have short forelegs. They use these forelegs to grasp food; to "box" each other (usually occurring between territorial males); and to help them rest comfortably as well as to get up from a resting position.

Answer 3

Kangaroos have long legs because they are especially adapted for bounding over long distances in Australia. Kangaroos have strong back legs and elongated hind feet for bounding. They have large, strong tendons in their hind legs which act as "springs". The springing motion requires less energy than running does, so kangaroos are able to bound for longer distances than other mammals with the standard four legs can run.

The short front arms balance the kangaroo for this long-distance bounding. If they had longer arms, they would be less efficient when they move. The short arms are the perfect length for grasping food, cleaning their pouch out (females) and for grooming.