Withholding information in semifree-ranging Tonkean macaques (Macaca tonkeana).

The ability of Tonkean macaques (Macaca tonkeana) to deceive partner about the location of hidden food was investigated in 4 males belonging to a group raised in a 2-acre park. Before releasing subjects in the search task, the experimenter prompted 1 of the subjects to observe where the bait was hidden. The authors found that when informed, higher ranking subjects did not significantly alter their search patterns whether tested alone or in pairs. The same held for subordinates belonging to pairs with weak dominance asymmetry. To the contrary, strongly dominated subordinates modified the number of pauses when searching in pairs. They used behavioral tactics such as avoiding being followed, stopping when being watched, or taking a wrong direction. Information withholding might be acommon event in macaques.