“…At the same time, primate signals in the auditory modality are also well described. Well-studied vocal signals include food calls (e.g., rhesus macaques Hauser 1992), the alarm calls of species such as vervet monkeys (Seyfarth et al 1980) and Diana monkeys (Zuberbühler et al 1997), but also signals that are almost certainly related to sexual selection, such as male loud calls (e.g., gelada, Gustison et al 2012; crested macaques, Neumann et al 2010) and copulation calls, which may occur in both females (e.g., Barbary macaques, Pfefferle et al 2008a, b; Semple and McComb 2000; long-tailed macaques, Engelhardt et al 2012; yellow baboons, Semple et al 2002) and males (rhesus macaques, Hauser 1993; Manson 1996). Although olfactory signals are less well studied (Heymann 2006a), there is increasing evidence that they play a significant role not just in strepsirrhines such as lemurs (Boulet et al 2009; Charpentier et al 2010), but also in platyrrhines (Ziegler et al 1993; Heymann 2006b) and even catarrhines (e.g., mandrills, Setchell et al 2011; chacma baboons, Clarke et al 2009; stump-tailed macaques, Cerda-Molina et al 2006).…”