Patterns and processes in chimpanzee hunting behaviour: the chimps and the carnivores: are they really so different?.

Abstract

Chimpanzees and large, social, mammalian carnivores hunt similarly, yet few studies use comparative methodologies to help understand these animals hunting behaviour. This thesis investigates the extent of current knowledge of chimpanzee hunting in the context of what, how and why chimpanzees hunt. Furthermore it investigates whether the high hunting success of chimpanzees is related to their choice of relatively small prey. This is done by comparing chimpanzee hunting to that of other social carnivores that hunt relatively large prey, wolves, Canis lupus, African hunting dogs, Lycaon pictus, spotted hyena, Crocuta crocuta, and the lion, Panthera leo.. Chimpanzees are highly successful hunters compared to large social carnivores. Chimpanzees preferentially hunt relatively small prey compared to the carnivores studied. The mediation analysis shows that the high hunting success of chimpanzees is partially mediated by them hunting prey of a smaller relative size. A comprehensive review of chimpanzees, Pan troglodytes, as predators as well as a mediation analysis on the relationship between prey size and hunting success across the five social predators is presented. It is shown that chimpanzees prefer hunting arboreal primates, particularly the red colobus monkey, Piliocolobus sp.. Seasonality in hunting prevalence occurs at some study sites but is not ubiquitous. Adult and adolescent males conduct the majority of hunts and often hunt in groups. Chimpanzees at the Taï Forest, Cote d’Ivoire, hunt more cooperatively (fulfilling different roles) than documented elsewhere. This has been likened to hunting by large social carnivores, specifically African lions and African hunting dogs. The traditional explanations of the reasoning behind chimpanzee hunting that have currently been proposed are not well supported. A more recently proposed explanation, the meat-­‐scrap hypothesis provides an important avenue for future research and the explanation for chimpanzee hunting is likely to be related to nutritional, rather than social factors.