It's the ape equivalent of Google Maps and Facebook. The night before a big trip, Arno the orangutan plots his journey and lets others know where he is going with a long, whooping call.
What he and his orangutan buddies do in the forests of Sumatra tells scientists that advance trip planning and social networking aren't just human traits.
A new study of 15 wild male orangutans finds that they routinely plot out their next day treks and share their plans in long calls, so females can come by or track them, and competitive males can steer clear.
The researchers closely followed the males as they travelled on 320 days during the 1990s. The results were published this week in the journal PLoS One.
Typically, an orangutan would turn and face in the direction of his route and let out a whoop, sometimes for as long as four minutes. Then he'd go to sleep and 12 hours later set on the heralded path, said study author Carel van Schaik, director of the Anthropological Institute at the University of Zurich.