A recent study has found that the adorable Australian marsupials prefer to use their left hands rather than their right ones when it comes to small, every day activities such as eating or grooming.
It’s a remarkable discovery as it proves that humans and primates aren’t the only creatures with a hand preference, and a surprising one as the brains of kangaroos were believed to lack the same neural connection between the right hemisphere and the left hemisphere that the above mentioned species are known to have. The new findings are now giving researchers reason to question that belief.
The study, published earlier this week, on Thursday (June 18, 2015), in the journal Current Biology, informs that kangaroos aren’t alone either. Other marsupials such as the red-necked wallaby have also shown signs of “handedness”, and they all prefer their left side.
Yegor Malashichev, project leader and biology professor at the St. Petersburg State University in Russia, gave a statement saying that “According to a special-assessment scale of handedness adopted for primates, kangaroos pulled down the highest grades. We observed a remarkable consistency in responses across bipedal species in that they all prefer to use the left, not the right, hand”.
What this means is that kangaroos not only have a hand preference, but they are also more true-handed than humans.
Professor Malashichev has spent a good number of years observing multiple species in the wild. He first noticed a preference for the left side back in 2002, while he was looking at amphibians. Right off the bat the theorized that such a behavior is very likely to be found in other vertebrates with paired appendages as well.
For this study, the project leader and his team looked at eastern gray and red kangaroos that were living in the wild in Tasmania and Australia. They noticed that the animals prefer to use their left hands for daily routines such as eating, collecting leaves, bending tree branches and grooming their noses.
Red-necked wallaby are a different story. The researchers found that they switch between hands depending on the activity that they’re doing. When they perform tasks that involve the fine manipulation of objects, they prefer to use their left limbs. When they perform tasks that require physical strength, they prefer to use their right limbs.
The Russian team was aided on location by Janeane Ingram, a wildlife ecologist and PhD student at the University of Tasmania. She gave a statement to BBC sharing that most of her colleagues don’t think that studying left-handedness in animals is a serious issue, however she argues that any study which proves true handedness in another species also reveals information about the species’ brain and about mammalian evolution.
Professor Malashichev and his team hope that their research will provide the scientific community with a better understanding of the marsupial brain and of parallel evolution (meaning that handedness appeared in both placental mammals such as primates and in marsupials, but there is no stage in evolution that links the two groups).
He goes on to add that similar, albeit non scientifically proven, preferences can also be seem in the way a parrot holds its food or in the paw a dog uses to shake your hand.