Mature male orangutans emit loud roars called long calls, audible more than a kilometer away. Studies suggested that long calls can announce the caller's identity, attracting females while warding off rival males. But do they transmit travel plans as well?
To find out, researchers monitored 15 wild males. While resting or feeding, the orangutans turned in different directions, and produced a total of over 200 long calls. When they eventually began to move, it tended to be in the direction they had faced while vocalizing. Additional long calls signaled changes in direction.
By planning and sharing their itineraries, the males influenced their peers. Females tended to move towards the caller's path, while subordinate males avoided it. For these apes, an impressive roar blazes a clear trail.
—Sophie Bushwick
[The above text is a transcript of this podcast.]
