Sept. 6, 2006 — Adult male chimpanzees act like school crossing guards by leading smaller chimps across man-made roads that dissect their forest habitats, according to a new study.
The finding, vividly captured on video, demonstrates that chimps display concern for family and friends and will risk their own safety to ensure the welfare of others. Scientists now believe such ability for care and consideration is present in certain primates, and not just humans.
"I think that we would definitely see this kind of behavior in other great ape species, and different populations may reveal cultural differences in protective orderings," said Kimberley Hockings, lead author of the study, which is published in Current Biology.
Hockings, a researcher at the University of Stirling in Scotland, and colleagues James Anderson and Tetsuro Matsuzawa observed a group of wild chimps in Bossou, Guinea, West Africa. The chimp group consisted of three adult males, five adult females, three juveniles and one infant.
Two roads dissect the chimps’ forest homeland. The first is a narrow road used by pedestrians, while the second is wider and carries trucks, motorbikes, cars, as well as pedestrians.
The scientists analyzed 19 instances where the chimpanzees crossed the two roads. In each instance, an adult male — often the alpha male named Yolo — would stand at the edge of the road. He then would carefully look left and right. Following his scan, the video footage shows him motioning with an arm.
At that point, the other chimps formed themselves into an ordered line and followed behind. The order nearly always consisted of adult males first with females, juveniles and the infant second. The leader, or another adult male, would then wait at the end of the line to assist the littlest ones.
When crossing the heavier traffic road, the second ranked male, Foaf, would continue to scan for vehicles and people while the elderly third male, Tua, and the alpha female took the lead. The researchers noted that the female would move into the more forward, leader position when the degree of crossing risk increased.
"They tend to travel in such ordered lines in risky situations such as road crossing and crop raiding," Hockings told Discovery News. "Depending on the situation, when moving through the forest, it is much more common that the chimpanzees are spread out."
