The Red kangaroo (Osphranter rufus) is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the largest extant marsupial. It is an iconic symbol of Australia and like all Australian wildlife, the Red kangaroo is protected by legislation.
The Red kangaroo has long, pointed ears and a square-shaped muzzle. Males have short, red-brown fur, fading to pale buff below and on the limbs. Females are smaller than males and are blue-grey with a brown tinge, and pale grey below, although arid zone females are colored more like males. Red kangaroos have two forelimbs with small claws, two muscular hind limbs, which are used for jumping, and a strong tail which is often used to create a tripod when standing upright. The Red kangaroo maintains its internal temperature at a point of homeostasis of about 36 °C (97 °F) using a variety of physical, physiological, and behavioral adaptations. These include having an insulating layer of fur, being less active and staying in the shade when temperatures are high, panting, sweating, and licking its forelimbs.
Red kangaroos inhabit the arid regions of Australia's mainland, except the extreme north and extreme southwest of the country, and the east coast. They can be found in scrubland, grassland, and desert habitats. They prefer open habitats with some trees for shade.
Red kangaroos gather in small groups of about 10, called "mobs." The groups are mainly made up of females and their young, with one or a few males. Females stay within the mob they were born in. Occasionally, huge numbers of these kangaroos congregate where there is excellent forage, sometimes up to 1,500 individuals. They are mostly active at twilight and during the night, resting during the day in the shade - but they sometimes move around during the day. They spend most of their active period grazing. When grazing in a group they are always looking out for danger and they warn others by stamping their feet. At this sign, young joeys will hop back into the pouch of their mother for safety. Red kangaroos are also adept swimmers and often flee into waterways if threatened by a predator. If pursued into the water, they may use their forepaws to hold the predator underwater so as to drown it.
Red kangaroos are polygynous animals, with males competing for mating opportunities with several females. They will try to have exclusive access to several females, actively driving away other males. Such competition sometimes results in "boxing" matches, when males hit at one another using their forepaws, and kick out with their feet. The breeding season is year-round if conditions are favorable. Females give birth usually to a single young, following a gestation period of about 32 to 34 days. When born, the joey climbs its way up through its mother's fur and into her pouch, where it remains, attached to a teat for 70 days. It first puts its head out of the pouch after 150 days, coming out for short periods after 190 days. A female lactates for about a year, carrying her joey in her pouch for around 235 days. Young females may first reproduce as early as 18 months of age and as late as 5 years during drought, but normally they are 2.5 years old before they begin to breed.
The Red kangaroo is faced with no major threats, and it continues to be an abundant and widely distributed species. Intensive agriculture would affect this species, but, as yet, not much of its habitat has been affected. Some argue, however, that competition with introduced rabbits and livestock, particularly during periods of drought, could be a threat. This kangaroo is in some areas so numerous that it is commercially harvested for its hide and meat, and sometimes also shot as a pest.
According to the Australian Government Department of the Environment, the total number of Red kangaroos is 11,514,298 individuals. This species' numbers are stable today and it is classified as Least Concern (LC) on the IUCN Red List.
The Red kangaroo has an important role in shaping communities of vegetation in the ecosystems where they live due to their action as grazers.