Apes can mentally track friends even when they’re hidden

By Stephen Beech

Out of sight isn’t out of mind for apes , reveals new research.

Bonobos can mentally track multiple members of their social circle – even when they can’t see them, say American scientists.

A series of “hide-and-seek” experiments with a bonobo named Kanzi have shown for the first time that apes can keep track of several familiar humans at once – even when they are hidden from view.

The findings also showed that Kanzi could also recognize caregivers from their voices alone – an ability never before tested on the species of endangered great ape.

The study, led by researchers from Johns Hopkins University in Baltimore, answers key questions about how animals manage to keep track of their pals.

And the team says their findings, published in the journal Proceedings of