Bouncing baby

2019-03-08 01:19:11

A SPRING in the step is the secret to making light work of parenting, at least if you’re an Australian wallaby. A female can carry a “joey” weighing up to 15 per cent of its own weight without any additional exertion, according to a new study. Russ Baudinette of the University of Adelaide and Andrew Biewener of Harvard University’s Concord Field Station measured the forces on tendons in the animals’ leg muscles as they hopped. They found the joey-laden mothers only need an extra bit of energy on the first hop. That energy is stored in their elastic tendons, giving them a boost on every subsequent jump (Nature, vol 395, p 653). Animals with this energy-saving gait probably had a selective advantage, says Biewener. “And it looks like a fun way to move,