Animals have culture like us, but will share theirs with other species

New research suggests that cultural practices in the animal kingdom can develop across species boundaries

- SOFIA QUAGLIA

On the lush, green Japanese island of Yakushima, two species of animals have struck up an unusual relationship, seemingly out of a fable.

The resident Japanese macaque monkeys and sika deer have developed a close, mutually beneficial inter-species bond.

The macaques ride around the island on the deers' backs like miniature jockeys, grooming their soft woolly fur as they go. In turn, the deer eat fruit discarded by the monkeys and head to their sleeping grounds at night to feast on the macaques' droppings, effectively cleaning the monkeys' homes.

And far from being a mere coincidence, it seems the two species actively give signals to one another to initiate the behaviour.

"There's a kind of observation, a kind of thinking or insight. I think that they really try to interact and to have benefits of interacting together," says Prof Cédric Sueur, an animal behavioural complexity expert based at the University of Strasbourg. "For me, they really understand [one other]."