Allogrooming behavior inCercocebus torquatus: The case for the hygienic functional hypothesis

The hygienic functional hypothesis of allogrooming behavior was examined in two captive groups (N=9 andN=8) of white-crowned mangabeys (Cercocebus torquatus lunulatus) by analyzing: (1) the corporal distribution of manipulation type according to hair density, and (2) the corporal distribution of allogrooming according to presence of wounds. In both groups the sites with higher hair density received more bouts of Superficial Grooming, which implies a tactile screening of a fragment of the body surface. Only one group tended 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 wounds concentrated predominantly on those sites which were accessible to the subject itself. Thus, our results may be consistent with the hygienic functional hypothesis of allogrooming behavior in general and with the sanitary one in particular.