Provisioning and the study of free-ranging primates: History, effects, and prospects

Abstract

Since the first field primate studies there has been debate over whether or not provisioning as an aid to observation of free-ranging groups alters behavior and population processes to the extent that those studies are not indicative of the animals' natural lives. If they are not, a significant amount of long-term data on several species of primates would be rendered irrelevant to analysis of natural population processes, and to the pool of knowledge of behavior and social groups on which a picture of historical and current selection pressures is built. At present these studies cannot be used comparatively with nonprovisioned studies due to lack of information on quantities of food supplement or certainty about effects of different provisioning methods on demography and behavior. The perception that Japanese primate studies are conducted largely on provisioned groups is inaccurate. An expanding number of study populations within Japan and most overseas studies are conducted without provisioning. Historically, the reason for provisioning the endemic Japanese macaque was to facilitate observation, but it has since become also a means of conservation. Provisioning in most other instances by both Japanese and Western primatologists has been done on an ad hoc basis. Studies of supplemental feeding effects on non-primate species suggest that food supply secondarily limits population density and fecundity is not the most important factor affecting population increase. Provisioning is essential to the survival of many primate groups and provisioned groups will likely increase. Studies of natural primate ecology should be used to determine the least intrusive methods of supplementary feeding.