Talk abstract: Lucy researches leave-taking in non-human primates, a significantly under-studied area in social behaviour. In this talk, Lucy will introduce us to this topic, situating it in an evolutionary context and outline the methods she has developed to investigate it. She will then discuss her research on chacma baboons (Papio ursinus) in Gorongosa National Park and argue that they exhibit leave-taking behaviour. As the first evidence of this behaviour in a wild, non-human species, she will then discuss the implications of these findings for our understanding of behavioural evolution.