President Obama, Oprah Winfrey, and Bill Gates are all lefties, and now they have unusual colleagues: kangaroos. According to a new study, some wild kangaroos tend to favor their left hands during common tasks like grooming and feeding. Yegor Malashichev, a Russian zoologist from Saint Petersburg State University and a co-author of the study, traveled to Australia to do the fieldwork. Along with his colleagues, he spent long hours observing seven species of marsupials living in the wild. Those species included red-necked wallabies, Goodfellow’s tree kangaroo, the eastern grey kangaroo, and the red kangaroo. The team watched as the animals groomed themselves, grabbed food with their paws, and leaned on their forearms while eating grass. Two species of kangaroo and one wallaby all showed the left-handed trend; some other marsupials, which walk on all fours, did not show the same bias. This new knowledge might seem pretty interesting in itself, but more importantly, the study, published in the journal Current Biology, could give scientists a better understanding of the evolution of mammals.