Name: Western grey kangaroo
Size: Females up to 39kg, males up to 72kg.
Diet: Mainly grasses, with some herbs, shrubs and trees.
Habitat/range: Forest, woodland, scrub and heath in all mainland states.
Conservation status: Least Concern
Superpower: Western grey kangaroos can dine out on 1080 poison bait without harm. They evolved resistance to natural 1080 in “poison bush” in south-west WA. Now they’re resistant across their range, so poison carrot in Queensland still makes a safe snack.
The western grey kangaroo tends to be the forgotten third kangaroo. Everyone knows about Big Red in the arid heartland of Australia, and people in the eastern states are familiar, sometimes all too familiar, with Skippy, the eastern grey. Western greys are the local kangaroo for people living in Western Australia and South Australia, but the range actually spreads 3,700 km across Australia, from Shark Bay in WA, through SA, western Victoria and western NSW, as far north as Charleville in Queensland. This range creates a challenging combination of cold, wet winters and hot, dry summers, so we know they’re tough too.
There are two subspecies: one across the Australian mainland and one found only on Kangaroo Island. Mainland western grey kangaroos all look much the same throughout their range. Despite the common name, these are mostly brown in colour, with even darker tips on their nose, ears, paws, toes and tail. Their face is always dark brown, but often has a pale highlight along the jawline, which matches their smoky grey belly fur. Tufts of white hair inside the ears make a nice contrast to the overall sombre look.
The Kangaroo Island subspecies is the macropod equivalent of a brown teddy bear, with short tail and legs, a tubby body and long fluffy fur. They evolved without predators on KI, so are naturally more trusting than mainland western greys. Unfortunately, this made them sitting ducks when the first European explorers arrived, keen for fresh meat. Now it makes them ideal for walk-though enclosures in fauna parks, although cuddling is still not recommended.
Female western greys are quite dainty, but males can only be described as boofy, with big heads and Roman noses. Males like to display their broad shoulders, long arms and sharp claws, and dance around in rather gentlemanly boxing sessions, until it gets serious. They often carry the scars of these bouts, with torn ears, scratched noses and even missing eyes. Males also have a strong smell, and are sometimes called “stinkers”, which is rather unkind (an odour that’s a bit like a curry, if you use your imagination).
Western grey kangaroos are seasonal breeders – it all happens in springtime. Last year’s youngsters are out of the pouch, bopping around madly and bumping into other roos. Females come into oestrus for just one day, so the stakes are high. Males kick, strangle, and eye-gouge each other during winner-takes-all fights for dominance. Couples mate for up to an hour, unless a rival male muscles in. A bean-sized baby, weighing less than a gram, is born a month later and stays safe and warm in the pouch until next spring. It’s a great time of year to be out amongst these wonderful Australian mammals.
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Originally published by Cosmos as Western grey kangaroo: at home across the vast outback
Graeme Coulson is an Honorary Principal Fellow in the School of BioSciences, University of Melbourne. He has worked on behavioural ecology and management of grey kangaroos for 50 years and has no plans to stop.
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