Toque macaque food calls: Semantic communication concerning food distribution in the environment

Abstract

Upon the rare occasions that wild toque macaques ( Macaca sinica) discover a large quantity of food in their natural forest environment they give distinctive calls. The durations of feeding bouts and the rates of feeding are significantly greater at sites where food calls are given than at sites of the same food types where no foods call are given. The calls designate a new location of a large quantity of any one of several food types. Dispersed group members hearing the call immediately run to the site of the call and feed there. I conclude that food calls are semantic signals (or symbols) that evoke the same response (rapid direct approach) as seeing the external referent of the calls (a source of abundant food) itself would. Food calls convey information about the presence of an edible food source, its quantity and location in the environment. As a general type, food calls appear to be related to, but are distinct from, contact calls which function to mintain group cohesion.