Family Macropodidae, Genus Macropus
No image of outback Australia is complete without a mob of kangaroos hopping across the horizon. Kangaroos belong to the Macropodidae family, meaning ‘big foot’ in Latin, in reference to the species’ unusually large hind feet.
What’s the difference between a kangaroo and a wallaby? The division is arbitrary: the species we call kangaroos are simply the larger animals in the Macropus genus.
These include the Red Kangaroo (Macropus rufus), Eastern Grey Kangaroo (M. giganteus), Western Grey Kangaroo (M. fuliginosus), Antilopine Kangaroo (M. antilopinus), Common Wallaroo (or Euro) (M. robustus) and the Black Wallaroo (M. bernadus).
The word kangaroo derives from 'Gangurru', the name given to Eastern Grey Kangaroos by the Guuga Yimithirr people of Far North Queensland. Kangaroos are of cultural and spiritual significance to Aboriginal people across Australia. Plus, their meat was, and continues to be, a staple protein source; pelts were used for clothing and rugs; and their skin crafted into water bags.
Kangaroos are the world’s largest marsupials. A Red Kangaroo can weigh 90kg and can grow two metres tall. Black Wallaroos, at around 20 kg, are the smallest species of the group (their name a portmanteau of wallaby and kangaroo).
All kangaroos have short hair, powerful hind legs, small forelimbs, big feet and a long tail. They have excellent hearing and keen eyesight. Depending on the species, their fur coat can be red, grey or light to dark brown.
Kangaroos are famous for their means of locomotion: hopping! They can reach speeds of 60kph, clearing more than 8m with a single hop!
Their muscular tail is used for balance when hopping, and as another limb when moving about. They also use their tail when swimming; that’s right – kangaroos are good swimmers! They swim to avoid predators, and can use their forepaws to drown pursuers.
Kangaroos can’t move backwards. It's for this reason that the Australian coat of arms features the emu and the kangaroo: two animals that can only move forwards as symbols of national progress.
Kangaroos are famous for their forward-opening pouch, where the joey (baby kangaroo) develops and suckles. A female kangaroo is known as a 'flyer' or a 'doe' and a male kangaroo a 'buck' or a 'boomer' (hence the nickname of the Australian men's basketball team, the Boomers). They live in social groups called mobs.
Where do kangaroos live?
Red Kangaroos are found over most of arid Australia, preferring flat open plains. Eastern Greys are found from Cape York to Tasmania; Western Greys have an equally wide distribution, from Western Australia to Victoria (both species prefer denser vegetation).
Antilopine Kangaroos live across northern Australia in monsoonal tropical woodlands, and Common Wallaroos are found over most of Australia, especially around rocky outcrops.
According to the IUCN Red List of Threatened Species, the Black Wallaroo, restricted to the sandstone country in the Northern Territory, is Near Threatened with extinction. The remainder of the species are widespread, common and considered of Least Concern.
Like all marsupials, kangaroos have pouches where the joeys are reared, drinking milk from mammary glands. Females have one young annually, however they’re able to keep extra embryos in a dormant state (‘embryonic diapause’) until the first joey leaves the pouch.
They can have a joey at their feet, one in the pouch and another in diapause all at the same time.
Incredibly, each of the female’s four teats provides different milk for the different stages of the joeys’ development.
Kangaroos hiss and growl when alarmed, females make clicking noises to communicate with their offspring, and males ‘chuckle’ during courtship!
Kangaroos are most active between dusk and dawn, as they search for their favourite foods: grass, as well as leaves, ferns, flowers, fruit and moss. Like cattle, they regurgitate their food, chewing it twice before it passes through their chambered stomach. Kangaroos need free water to survive; however, when desperate, kangaroos are known to dig holes a metre deep in search of water.
Threats to kangaroos
Kangaroos have few natural predators: Dingoes, humans, Wedge-tailed Eagles and, before their extermination, Tasmanian Tigers.
Introduced carnivores, such as wild dogs and foxes prey on the young, and introduced herbivores compete with kangaroos for food.
European settlement has actually been positive for several kangaroo species because of: the introduction of permanent water sources (bores, tanks and dams); the provision of pasture grasses; the extinction of Tasmanian Tigers and the extermination of Dingoes across vast landscapes. In some areas, kangaroos are overabundant. This isn’t the case for the Antilopine Kangaroo or the Black Wallaroo, whose numbers are decreasing.