Experts studying chimpanzees while investigating the evolution of human social behaviour have uncovered their ability to safely cross roads.
They said the discovery has shown chimps' ability to cope with the risk of man-made situations.
The University of Stirling research was carried out with a small chimp community in West Africa.
It found the dominant adult males took up protective positions in the group when it was tasked with crossing roads.
The study at Bossou, Guinea observed the chimpanzees crossing two roads - one large and busy with traffic and the other smaller and used mostly by pedestrians.
The less fearful and physically larger adult males took up forward and rear positions, with the adult females and young occupying the protected middle space.
The study has built on prior research showing that adult male monkeys took similar action to reduce the risk of being attacked by predators when travelling towards potentially unsafe areas, such as waterholes.
Kimberley Hockings, who worked on the study, said: "Road-crossing, a human-created challenge, presents a new situation that calls for flexibility of responses by chimpanzees to variations in perceived risk, helping to improve our understanding about the evolution of human social organisation.
"Dominant individuals act cooperatively with a high level of flexibility to maximise group protection."