The Red Kangaroo (Macropus rufus) is the largest of all kangaroos, the largest mammal native to Australia, and the largest surviving marsupial. It is found across mainland Australia, avoiding only the more fertile areas in the south, the east coast, and the northern rainforests.
This species is a very large kangaroo with short, red-brown fur, fading to pale buff below and on the limbs. It has long, pointed earlobes and a squared-off muzzle. Females are smaller than males and are blue-grey with a brown tinge, pale grey below, although arid zone females are coloured more like males. It has two forelimbs with small claws, two muscular hindlimbs, which are used for jumping, and a strong tail which is often used to create a tripod when standing upright.
The Red Kangaroo's legs work much like a rubber band. The males can leap over nine meters in one leap.
Males grow up to a body length of long and weigh up to 85 kg (187.4 lb). Females reach a body length of up to long and weigh up to 35 kg (77.2 lb). Tails can be from up to long. The average Red Kangaroo stands approximately tall. Accounts of sizes greater than this are not uncommon, with some large males reportedly reaching approximately .
The Red Kangaroo maintains its internal temperature at a point of homeostasis (about 36°C) using a variety of physical, physiological and behavioural 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.
The Red Kangaroo inhabits most of the dry inland of the central part of Australia in small groups called mobs. It prefers open plains where trees and bushes are scarce.
The Red Kangaroo's range of vision is approximately 300 degrees due to the position of its eyes. A human's range of vision is around 180 degrees in comparison.
The Red Kangaroo is mainly active in the cool of the evening or night, and lives alone or in small groups called 'mobs' (although food shortages can cause them to congregate into larger groups). Membership of these groups is very flexible, and males (boomers) are not territorial, fighting only after females (flyers) which come into heat. The largest males are dominant, and control most of the matings.
The Red Kangaroo is nocturnal and crepuscular, and largely spends the daylight hours sleeping or otherwise relaxing.
The Red Kangaroo prefers to eat grasses and other vegetation. It can go long periods of time without water, as long as it has access to green plants as they have the ability to take moisture out of plants.
The dental formula of a kangaroo is the same dental formula as for macropods:
The Red Kangaroo breeds all year round. The females have the unique ability to delay birth of their baby until their previous Joey has left the pouch. This is called embryonic diapause. The gestation period is around 33 days. The young Joey will permanently leave the pouch at around 235 days old, but will continue to suckle until it reaches 12 months of age.
When male kangaroos fight, they may appear to be 'boxing'. They usually stand up on their hind limbs and attempt to push their opponent off balance by jabbing him or locking forearms. If the fight escalates, they will begin to kick each other. Using their tail to support their weight, they deliver kicks with their powerful hind legs.