Cooperative problem solving in a social carnivore

Keywords: cooperation Crocuta crocuta group hunting intelligence primate social cognition spotted hyaena Numerous field researchers have described cooperative hunting in social carnivores, but experimental evidence of cooperative problem solving typically derives from laboratory studies of nonhuman primates. We present the first experimental evidence of cooperation in a social carnivore, the spotted hyaena, Crocuta crocuta. Eight captive hyaenas, paired in 13 combinations, coordinated their behaviour temporally and spatially to solve cooperation tasks that modelled group-hunting strategies. Unlike many primates that cooperate infrequently or require extensive shaping, spotted hyaenas displayed a natural aptitude for teamwork: all teams achieved success rapidly, repeatedly, and without specific training. Social influences on cooperative performance included an audience effect that could influence party formation and hunting success in the wild. Performance also varied across dyads, notably with rank-related aggression between partners impairing performance. Efficiency improved as partners increasingly attended to one another and coordinated their actions. Lastly, experienced cooperators modified their behaviour to accommodate a naı¨ve companion, using visual monitoring and tracking to promote coordination. We suggest that social carnivores should be considered relevant models for the study of cooperative problem solving, as their abilities provide a comparative framework for testing theories about the mechanisms of social learning and the evolution of intelligence. Animal cooperation has held significant interest to evolutionary biologists (Axelrod & Hamilton 1981) and comparative psychologists , particularly with regard to understanding the cognitive implications of cooperation in our own species. In experimental studies of cooperative problem solving, at least two animals must jointly perform similar or complementary actions to obtain a food reward. For animals to be considered 'cooperators' within this paradigm, partners must pursue their common goal while taking account of each other's behaviour (Chalmeau & Gallo 1996). The level of behavioural organization between participants can vary, increasing in temporal and spatial complexity from mere similarity of action, to synchrony (similar acts performed in unison), then coordination (similar acts performed at the same time and place), and finally collaboration (complementary acts performed at the same time and place: Boesch & Boesch 1989). For over seven decades, such studies have focused almost exclusively on nonhuman primates (for an exception in corvids, see Seed et al. 2008), reflecting a general premise that higher-order cognitive functioning in large-brained or highly encephalized animals should enable organized teamwork. Curiously, however, primates are often inefficient at solving cooperation problems in the laboratory, potentially reflecting a weak tendency to …