Why do Kangaroos jump instead of walk?

Question

This might be a really weird question, but why do Kangaroos jump instead of walk?

As a human jumping takes a lot more energy than jumping, so it must be something biological, but they are like the only animal family that does that (I’m sure there are more kangaroo-like animals I don’t know about)?

Edit – After seeing a few comments, this post isn’t about why the evolved to do so (even though it is an interesting question), I was asking what is the anatomical reasoning for it.

In: 418

Answer 1

while kangaroos hop tendons in their legs act as springs, something above 40% of the energy from each jump is recycled into the next making them twice as efficient as a human runner, far more efficient than any comparable animal. At low speeds this doesn’t work so they kind of hobble with all four limbs and their tail instead.

There is speculation that, as marsupials they have a lower body temperature than placental mammals so they have less available energy and hopping was possibly evolved as a way to go faster for less energy.

The real question is ‘why don’t more animals hop?’