ORIGINAL PAPER Discrimination of familiarity and sex from chemical cues in the dung by wild southern white rhinoceros Ivana Cinkova ´ • Richard Policht Received: 27 December 2013 / Revised: 14 September 2014 / Accepted: 17 September 2014 / Published online: 2 October 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract Communication in rhinos is primarily mediated by the vocal and olfactory signals as they have relatively poor eyesight. White rhinos are the most social of all the rhinoceros species, they defecate at common dungheaps and the adult bulls use dung and urine to mark their terri- tory. Chemical communication may therefore be particu- larly important in the social interactions of white rhinos, and its knowledge could be very helpful in their manage- ment and conservation. However, no studies have investi- gated up until now the olfactory discrimination in any rhinoceros species in the wild. We have experimentally studied the reactions of the wild southern white rhinos (Ceratotherium simum) to the dung of familiar and unfa- miliar adult females and adult territorial males. We regis- tered the number of sniffing events, the duration of sniffing and the latency of the vigilance posture from the onset of sniffing. The dung of unfamiliar rhinos was sniffed longer than that of familiar rhinos. The rhinos showed a shorter latency of vigilance posture to the familiar dung of males than that of females. For unfamiliar dung, they displayed a shorter latency of vigilance posture to female than male dung. Our results indicate that the rhinos are able to discriminate the familiarity and sex of conspecifics from the smell of their dung. Olfactory cues could therefore play an important role in the social relationships and spatial organization of the southern white rhinoceros. Keywords Southern white rhinoceros Á Ceratotherium simum Á Olfactory discrimination Á Communication Á Dung Á Familiarity Introduction Olfactory signals have an advantage in that they persist for some period of time in the absence of the depositor and allow the receivers to specifically assess certain parameters of their social environment (Eisenberg and Kleiman 1972). Terrestrial vertebrates perceive olfactory signals via the main olfactory system, which is receptive to volatile sig- nals and through the vomeronasal system, which primarily processes non-volatile pheromones (reviewed by Dulac and Torello 2003). Olfactory signals often play an important role in the communication of ungulates (Grau 1976), which have a well-developed vomeronasal organ (Eisenberg and Kleiman 1972). Vocal and olfactory signals are extremely important for communication in rhinos as they have an excellent sense of hearing and smelling, but relatively poor eyesight (Penny 1987). Cinkova ´ and Policht (2014) have recently determined that the contact calls of white rhinos contain information on the individual identity, age class, context and species of the caller (northern versus southern white rhinoceros) and similar information about the sig- naller may be present in their olfactory cues. Scent-mark- ing behaviours provide honest signals of competitive ability and quality of the signaller to conspecifics in mammals. The receivers assess the signallers by use of I. Cinkova ´(&) Department of Zoology and Laboratory of Ornithology, Faculty of Science, Palacky ´ University, 17. listopadu 50, 771 46 Olomouc, Czech Republic e-mail: ivanacinkova@centrum.cz R. Policht Department of Ethology, Institute of Animal Science, Prague, Czech Republic R. Policht Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic 123 Anim Cogn (2015) 18:385–392 DOI 10.1007/s10071-014-0810-8