It turns out that most kangaroos are left-handed, according to a new study by researchers at Saint Petersburg State University in Russia. While doing field research in Australia, the researchers found that 95 percent of the marsupials favor their left paws for physical activity.
This is a surprise because previous studies supported the idea that 'true' handedness is a unique feature of primates. These new findings change that, and researchers now conclude that other species that stand on two legs have evolved a dominant hand.
“What we observed in reality we did not initially expect,” Dr. Yegor Malashichev, a zoologist at the university and co-author of the study, said in a statement. "But the more we observed, the more it became obvious that there is something really new and interesting in the wild."
For the study, the researchers observed three species of kangaroo and one closely related species of wallaby in nature. While all of the animals used their left paws to eat and to groom themselves, the eastern gray kangaroo and the red kangaroo used their left paws exclusively, for all tasks.
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Eastern grey kangaroo using its left paw to gather food.
This research has significance beyond the Outback -- the more species scientists find with hand dominance, the more they understand about brain symmetry, or rather asymmetry. Left handedness is known to have roots in the right side of the brain in humans and other primates, so roo brains may have dominant sides as well.
That marsupials, not just primates, have paw-preference also helps researchers uncover the evolution of handedness.
"Any study that proves true handedness in another bipedal species contributes to the study of brain symmetry and mammalian evolution," Janeane Ingram, a wildlife ecologist who worked with the St. Petersburg State team in Australia, told the BBC.
The study was published online in the journal Current Biology on June 18, 2015.