ABSTRACT
On account of their close relationship with man, the so-called non-human primates are of particular interest to zoologists, anthropologists and sociologists. Social signals are in fact more intensive and more conspicuous in many cases where captive animals are compared with those in the wild, and certain signals (and their significance) are rendered much more obvious when seen at the highest level of intensity. Only the possible biological function of these signals have been discussed, whilst the underlying physiological causes have been considered only in passing. In addition, the morphological features of the genital signals vary widely from species to species, as is common for other intraspecific signals. Sexual signals also have social significance, presentation acting as a greeting ceremony. In the female the sexual skin activity primarily underlines the sexual presentation. The main source for counterbalancing intra-group agonistic tendencies is behaviour patterns and/or signals from the sexual and brood-care context.
