Kibale’s chimps used sticks to probe holes containing water and honey. They used sticks to hit and threaten each other. They played with them. And, finally, they carried sticks — holding them under their arms or in their laps, for hours at a time, even while walking and climbing and feeding and resting.
“Regular stick-carrying has no discernible function,” wrote Wrangham and Kahlenberg, yet it accounted for more than one-third of all stick use.
Carried sticks were shaped differently than sticks used as weapons or probes, and “unlike other types of stick use, carried sticks were regularly taken into day-nests … where individuals rested and were sometimes seen to play casually with the stick in a manner that evoked maternal play,” wrote the researchers.
Stick-carrying was also most frequent in juveniles, particularly juvenile females. With parenthood it invariably ceased.
Tuesday, December 21, 2010
Girl Chimpanzees May Use Sticks as Dolls