Red Kangaroo (Osphranter rufus): Facts, Size and Speed

Appearance

Red kangaroos have long, pointed ears, a square-ended muzzle, short front limbs with small claws, very long hind feet and a thick, muscular tail. A pale stripe runs from the corner of the mouth toward the ear, and there are black and white markings on the side of the muzzle, features that help separate it from gray kangaroos.

Males are usually covered in short, reddish-brown fur, with paler fur underneath. Females are smaller and often blue-gray, so they are sometimes called blue fliers. In parts of the arid zone, however, females are reddish like the males. Adult males also develop much larger shoulders, chest and forearms than females, which they use when fighting.

The second and third toes of each hind foot are joined together and used as a grooming comb. The large fourth toe takes most of the weight during hopping.

Size

The red kangaroo is strongly sexually dimorphic: males are often twice the weight of females or more. Full details are in how big is a red kangaroo?

Males keep growing throughout much of their lives, so the biggest “big reds” are older males.

Habitat and range

Red kangaroos live across most of the dry interior of mainland Australia, from western New South Wales and Queensland through South Australia and the Northern Territory to Western Australia. They are absent from the wetter coasts of the east, south and far southwest, the northern tropical rainforests and Tasmania.

They prefer open plains, grassland, shrubland and desert country with a few trees or bushes for shade. During the hottest part of the day they rest under shrubs such as saltbush or mulga trees and scrape shallow beds in the soil.

Most red kangaroos stay within a home range, but they move long distances when rain falls somewhere else and fresh grass sprouts. Individuals have been recorded traveling more than 200 km (125 mi). The spread of sheep and cattle farming, with its artificial waterholes, has made more of inland Australia suitable for them.

Diet and water

Red kangaroos are herbivores. They graze mainly on green grasses and forbs (small, soft-stemmed flowering plants), and they are good at finding green shoots even when most of the landscape looks brown. In dry times they also eat some shrubs, including certain saltbushes and bluebushes.

Like cattle, kangaroos ferment plant food with microbes in a large, chambered stomach, and they sometimes bring food back up to chew again. Their kidneys produce very concentrated urine, saving water, so they can go long periods without drinking if their food is green. They keep cool by resting in the shade, panting, sweating when active and licking their forearms, where a network of blood vessels lies close to the skin. As the saliva evaporates, it cools the blood.

Red kangaroos are mostly active at dusk, at night and in the early morning, when it is cooler.

Hopping and speed

Red kangaroos are among the most efficient large travelers on land. When they hop, the long Achilles tendons in their hind legs stretch on landing and spring back, like a pogo stick, returning much of the energy for the next bound. Classic experiments on red kangaroos in the 1970s showed that, above a slow speed, they can hop faster without using much more energy.

They cruise comfortably at around 20–25 km/h (12–16 mph) and can reach about 55–65 km/h (35–40 mph) in short bursts. A single bound can cover about 8–9 m (26–30 ft), and leaps up to about 3 m (10 ft) high have been reported. See how high can a kangaroo jump? for more.

At slow speeds while grazing, kangaroos use a “five-legged” walk: they balance on their front legs and tail, then swing both hind legs forward together. Research has shown the tail actively pushes the body forward during this movement. Red kangaroos are also capable swimmers.

Behavior and social life

Red kangaroos live in loose groups called mobs. Most groups are small, often 2–10 animals, usually females with their young plus one or more males. Membership changes often. When rain produces lots of fresh grass, hundreds of kangaroos may gather in one area, and groups of up to about 1,500 have been reported.

Males are called boomers and females are called flyers or does. Males are not territorial, but they compete fiercely for access to females in breeding condition. Young males spar often, while serious fights between big males decide who mates. These contests involve wrestling, pushing and powerful kicks delivered while balancing on the tail. Read more in why do kangaroos box?

Kangaroos warn each other of danger by thumping the ground with their hind feet.

Reproduction and joeys

Red kangaroos can breed at any time of year when conditions are good. Pregnancy lasts only about 33 days. The newborn is tiny, around 2.5 cm (1 in) long and less than 1 g (0.04 oz), blind and hairless. Using its front limbs, it crawls through its mother’s fur into the forward-facing pouch in a few minutes and attaches to a teat.

The young, called a joey, first leaves the pouch at about 190 days and leaves it for good at around 235 days. It keeps suckling from outside the pouch until about 12 months old. Find out more in what is a baby kangaroo called?

Females usually mate again soon after giving birth. The new embryo stops developing at a very early stage, a process called embryonic diapause, and only resumes when the older joey is about ready to leave the pouch or if it dies. A mother can therefore have a young-at-foot drinking milk, a smaller joey in the pouch and a paused embryo all at once, producing two different kinds of milk for her two joeys at the same time. Females can start breeding at about 15–20 months and males at about 2 years, though maturity is delayed in drought.

Lifespan, predators and threats

Red kangaroos can live up to about 22 years in the wild, but few do. Many joeys die in their first year, especially during droughts, when mothers cannot produce enough milk. In captivity they commonly live into their teens.

Adult red kangaroos are too large for most predators. Dingoes are the main natural predator and sometimes hunt adults in packs, while wedge-tailed eagles take young joeys. Large saltwater crocodiles can catch kangaroos where their ranges meet in the north.

Drought is the biggest natural threat, and numbers can crash when rains fail for several years. In the severe droughts of the early 1980s, aerial surveys recorded large falls in kangaroo numbers, in some regions of around half. Red kangaroos cope by moving toward areas where storms have produced green grass, by resting in shade through the heat of the day, and by breeding less: females in poor condition stop raising young until rain returns. When good seasons come back, the population can recover quickly, because females breed again within weeks and paused embryos restart their development. People also affect red kangaroos through collisions with vehicles, competition with livestock and introduced rabbits for food, and regulated commercial harvesting, which is controlled by state management plans and is a subject of public debate.

Conservation status

The IUCN Red List classifies the red kangaroo as Least Concern. It is common and widespread, and its total population is usually estimated in the millions, rising and falling with rainfall. All kangaroos are protected by law in Australia.

Myths and facts

Myth: “kangaroo” means “I don’t know”. A popular story says Aboriginal people answered Captain Cook’s crew with a word meaning “I don’t understand”. In fact, the word comes from gangurru, the Guugu Yimithirr name for the gray kangaroo, recorded near present-day Cooktown in 1770.

Myth: kangaroos are related to deer or rabbits. Kangaroos are marsupials, more closely related to wombats and the koala than to any hoofed mammal or rodent.

Relationship with people

The kangaroo is a national symbol of Australia. It appears with the emu on the Australian coat of arms and on coins, stamps and airline logos. For Aboriginal peoples, kangaroos have been an important source of food, skins and tools for many thousands of years and feature in many traditional stories.

On rural roads, kangaroos are a common cause of vehicle collisions, especially at dusk and night. Many visitors see wild red kangaroos in outback national parks such as Sturt National Park in New South Wales. The best times to watch them are early morning and late afternoon, when they come out of the shade to graze on open plains. Watch quietly from a distance and never feed them, since kangaroos that learn to expect food from people can become pushy and even aggressive.