Allogrooming behavior in Cercocebus torquatus: The case for the hygienic functional hypothesis

The hygienic functional hypothesis of allogrooming behavior was examined in two captive groups (N=9 and N=8) of white-crowned mangabeys (Cercocebus to rquatus lunulatus) by analyzing: (1) the corporal distribution of manipulat ion type according to hair density, and (2) the corporal distribution of al logrooming according to presence of wounds. In both groups the sites with h igher hair density received more bouts of Superficial Grooming, which impli es a tactile screening of a fragment of the body surface. Only one group te nded to emit more allogrooming on the body sites when they were wounded. In the other group, however, the number of wounds was very small and the woun ds concentrated predominantly on those sites which were accessible to the s ubject itself. Thus, our results may be consistent with the hygienic functi onal hypothesis of allogrooming behavior in general and with the sanitary o ne in particular.