More than 25 years ago, the first major review of primate communication appeared (Altmann, 1967). Since then, information on the communicative abilities of primates increased rapidly, resulting, 15 years later, in the appearance of the first volume in which signaling systems were analyzed in a broader variety of primate groups within an evolutionary perspective (Snowdon, Brown and Petersen, 1982). Seven years later, the first volume dedicated solely to primate vocal communication appeared (Todt, Goedeking and Symmes, 1988) and another four years later a volume followed in which nonverbal...