Eight metres a hop

Kangaroo

It is the only large animal in the world that travels by hopping, and it does so because it pays: past a certain speed, hopping costs it less energy than running.

A red kangaroo hopping over the red earth of a plain with dry scrub
A red kangaroo in the arid interior. The tendons of its hind legs work as a spring and give it back much of the energy of each hop.

A kangaroo is any of the large macropods (the group of marsupials that also takes in the wallabies and the tree-kangaroos, 45 species in all). The term kangaroo is sometimes used in a wider sense to refer to every member of the macropod family.

The young is born after thirty-three days of gestation, blind and hairless, and is little more than a couple of centimetres long 1. It climbs to the pouch on its own, where it takes hold of a teat and spends the next eight months.

The four large species

Kangaroos proper
Species Scientific name Weight
Genus Osphranter
Red kangaroo Osphranter rufus 90 kg
Antilopine kangaroo Osphranter antilopinus 70 kg
Genus Macropus
Eastern grey kangaroo Macropus giganteus 66 kg
Western grey kangaroo Macropus fuliginosus 54 kg

1 It weighs less than a gram at birth, and multiplies its weight a hundred thousand times before leaving the pouch.