Communication is a crucial mechanism at the basis of animal social behaviour and likely to be of central importance in facilitating the evolution of complex animal societies. This thesis aims to expand our knowledge of the olfactory, vocal and multi-modal communication of wild African lions. Much of our understanding of lion behaviour originates from studies in East Africa, yet the ancestral lion may have been a wetland specialist in habitats such as the Okavango Delta. Here I first employ an established playback design to test whether lions can determine the number of conspecifics calling in large vocal choruses, demonstrating that the upper limit for lions to assess the number of simultaneous callers is three, matching the ability of humans performing a similar task. I then use a novel playback experiment to demonstrate that lions are capable of cross-modal processing of information on individual identity; an ability originally thought to be unique to humans and not previously demonstrated in wild animal populations. Next, I provide a novel and detailed investigation into the olfactory communication of lions. First I analyse the scent-marking of lions and the responses of group members to marks, and demonstrate that chemical signals may play an important role in the social lives of prides. I then use a scent presentation experiment to test the function of urinary scent-marks in communication within and between prides, determining that lion urine signals the social group and sex of the depositor and may be important for sexual assessment and territory defence. Overall this thesis significantly advances our knowledge of the vocal and olfactory communication of African lions, and provides the first evidence that lions are capable of cross-modal individual recognition during communication between conspecifics. Together these results highlight that olfactory and multi-modal communication are important for lions, despite being previously overlooked
