Social factors influencing performance of a foraging task for captive chimpanzees

The performance of captive chimpanzees (Pan troglodytes) during a simulated foraging activity was compared to that reported for the foraging behavior of wild chimpanzees. The ability to find hidden fruit in a large outdoor play area was measured for 34 subjects housed in ten separate groups. Sex differences were apparent, with females searching for and finding significantly more fruit than males did. Chimpanzees of high and medium dominance rank found more fruit than those of low rank. Neither age nor stage of the female sexual cycle exerted an influence. The subjects became more proficient at finding fruit during the second block of trials. The results reflect possible influences of captivity on chimpanzee social behavior.