Social foraging in captive baboons: implications for enrichment

Abstract

Positive affective states guide the proximate performance of the appetitive and consummatory components of behaviours, such as foraging, that ultimately increase an animal’s fitness. Accordingly, promoting foraging in captive animals can enhance their welfare, defined as a predominance of positive (e.g. pleasure) over negative (e.g. stress) affective states. In three sets of experiments, I examined social foraging in two captive baboon troops housed at the Johannesburg Zoo, South Africa. I investigated (1) whether watching a demonstrator baboon forage cued conspecific observers to also forage; (2) how two factors known to influence the social transfer of foraging information and the motivation to forage (demonstrator status and hunger/satiation respectively) affected whether an animal was cued to forage upon watching a demonstrator forage; (3) the psychological mechanism through which this change in motivation to forage occurred; and (4) how socially-cued foraging behaviour could be incorporated into environmental enrichment protocols. I recorded the frequency of foraging for individual baboons and for each troop as a whole. I also scored the incidence of aggression in both troops. Upon watching a demonstrator forage from a monopolisable food source, observers increased their foraging efforts elsewhere in the enclosure. Demonstrator identity influenced the incidence of foraging by observers, with how well the demonstrator predicted food reward, rather than its status per se, determining observer foraging frequency. The psychological mechanism mediating the increase in foraging behaviour, as well as the effect of observer hunger/satiation on foraging, were unclear. The increased frequency of foraging by observers was accompanied by only a small rise in aggression. My data indicate that the use of social cues to motivate foraging behaviour could be employed to augment standard foraging enrichment protocols aimed at improving the welfare of captive animals.