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| Grey Kangaroo |
The Eastern Grey Kangaroo (Macropus giganteus) is a marsupial found in southern and eastern Australia, with a population of several million. It is also known as the Great Grey Kangaroo and the Forester Kangaroo. Although a big Eastern Grey male typically masses around 66 kg (weight 145 lb.) and stands almost 2 m (6 ft.) tall, the scientific name, Macropus giganteus (gigantic large-foot), is misleading, as the Red Kangaroo of the semi-arid inland is, at 85 kg, larger.
Description Grey Kangaroo
The Eastern Grey is easy to recognise: its soft grey coat is distinctive, and it is usually found in moister, more fertile areas than the Red. Red Kangaroos, though sometimes grey-blue in colour, have a totally different face to Grey Kangaroos. Red Kangaroos have distinctive markings in black and white beside their muzzles and along the sides of their face. Grey Kangaroos do not have these markings, and their eyes seem large and wide open. Where their ranges overlap, it is much more difficult to distinguish between Eastern Grey and Western Grey Kangaroos, which are closely related. They have a very similar body shape and facial structure, and their noses/muzzles are fully covered with fine hair (though that is not obvious at a distance, their noses do look noticeably different to the noses of Reds and Wallaroos). The Eastern Grey's colouration is a light-coloured grey or brownish-grey, with a lighter silver or cream, sometimes nearly white, belly. The Western-grey is a dark dusty brown colour, with more contrast especially around the head. Indigenous Australian names include iyirrbir (Uw Oykangand and Uw Olkola) and kucha (Pakanh). The highest ever recorded speed of any kangaroo was 64 kilometres per hour (40 mph) set by a large female Eastern Grey Kangaroo.
Ecology Grey Kangaroo
Although the Red is better known by reputation, the Eastern Grey is the species most commonly seen and the Kangaroo most often encountered in Australia, due to its adaptability. Few Australians visit the arid interior of the continent, while many live in and around the major cities of the south and east coast, from where it is usually only a short drive to the remaining pockets of near-city bushland where kangaroos can be found without much difficulty. It prefers open grassland with areas of bush for daytime shelter and mainly inhabits wetter parts of Australia. It also inhabits coastal areas, woodlands, sub-tropical forests, mountain forests, and inland scrubs.
Like all kangaroos, it is mainly nocturnal and crepuscular, and is mostly seen early in the morning, or as the light starts to fade in the evening. In the middle of the day, kangaroos rest in the cover of the woodlands and eat there but then can out in the open to feed on the grasslands in large numbers. The Eastern Grey Kangaroo is predominantly a grazer, eating a wide variety of grasses, whereas some other species (e.g. the Red Kangaroo) include significant amounts of shrubs in the diet.
Behaviour Grey Kangaroo
Eastern grey kangaroos are gregarious and form open-membership groups. The groups are made up of 2-3 females and their offspring with the same number of males of which one is dominant. They exist in a dominance hierarchy and the dominant individuals gain access to better sources of food and areas of shade. However, kangaroos are not territorial and usually fight only when females are in estrous. Dominant males rarely stay dominant over a year and it is not uncommon for one to die shortly after changes in environmental conditions. Dominant male kangaroos rarely keep their position for more than a year.
Eastern grey kangaroos adjust their behaviour in relation to the risk of predation with reproductive females, individuals on the periphery of the group and individuals in groups far from cover being the most vigilant. Vigilance in individual kangaroos does not seem to significantly decrease when the size of the group increases. However there is a the tendency of the proportion of individuals on the periphery of the group to decline as group size increases. The open membership of the group allows more kangaroos to join and thus provide more buffers against predators.