The iconic Eastern grey kangaroo is a marsupial with thick, soft, grey-brown fur, which is paler on the underparts. Its muzzle is finely haired and it has dark tips to its paws, feet and tail. Sometimes it has a darker line along its back. Males are similar in appearance to females but are much larger, with their head, chest and forelimbs being more heavily muscled. These kangaroos are distinguished from the western grey kangaroo, a close relative, by their grey coloration, rather than brown, and a much paler face, with a contrasting dark eye ring, and more rounded, shorter, hairier ears.
The Eastern grey kangaroo is widely distributed across eastern mainland Australia, from northeast Queensland to South Australia in the southeast, and southern Victoria, including eastern Tasmania, and it has been introduced to Three Hummock Island and Maria Island. This kangaroo inhabits areas which have a higher rainfall, including woodland, mallee scrub, dry sclerophyll forest, shrubland and heathland. It needs trees or scrub for cover, along with open areas for feeding. It can occur also in introduced grassland, agricultural land, and other modified landscapes.
Being a social species, Eastern grey kangaroos usually live in mobs or small groups, which include one dominant male, 2-3 females and their young, and 2-3 young males. They spend most of the day in the shade, moving out at dusk, and feeding until dawn. The adults communicate with their young and with each other using clucking noises. When they are alarmed, they can make a guttural cough, also used when males are warning each other, fighting, or displaying dominance. Grey kangaroos stamp on the ground with their hind legs when they sense danger, which, as well as the guttural noise, issues an alarm sound that can be heard from a great distance
Eastern grey kangaroos are polygynous animals. Adult males take part in ritualized fights with rivals, and the dominant male being the most likely the only one to mate with the available females. Breeding continues throughout the year, peaking in summer. The young is born following a gestation period of 36 days. At about 9 months old, the joey leaves its mothers pouch for short periods, exploring the world with very brief little hops around mother. Joey leaves its mothers pouch at 11 months old, though it is still suckling. When the joey is 18 months old it is fully weaned and leaves the pouch permanently. Females are sexually mature at about 20 to 22 months, males at 43 months.
The Eastern grey kangaroo is not under any major threats. However, it is regarded as a pest in many areas, and is killed under license. It is also hunted commercially for meat and leather. Its population is more limited in some areas, particularly in locations that are densely settled, and there is some doubt whether they will be able to sustain present hunting levels. Some locally abundant populations are culled by state wildlife agencies to reduce the impact of grazing on native vegetation, as well as to improve animal welfare. More concern has been expressed over the subspecies Forester Kangaroo, these animals being threatened by agricultural clearing, which reduces their habitat.
According to the Australian Government Department of the Environment, the total number of the Eastern grey kangaroo is 16,057,783 individuals. Currently this species’ numbers are stable and it is classified as least concern (LC) on the IUCN Red List.
Being grazing animals, Eastern grey kangaroos control the spread and growth of grasses and other foliage. This could result in soil degradation if it is left unchecked, but kangaroo population numbers are not large enough to be a serious ecological hazard.