MOVING UP THE DOMINANCE HIERARCHY IN YOUNG SOOTY MANGABEYS

In contrast to the matrilineal dominance system reported for several p rimate species, sooty mangabeys, Cercocebus torquatus atys, exhibit a dominance system that is independent of matriline except in the first years of life. Beginning as early as 2-3 years of age, juveniles may b egin to outrank both their mothers and other initially higher-ranking individuals. The present study followed 12 juvenile sooty mangabeys ra nging in age from 2 to 5 years over a 6-month period to assess the mea ns by which higher dominance rank is attained. Four behavioural patter ns were identified: (1) directly challenge a higher-ranking animal (57 .1%); (2) join with an aggressor against a higher-ranking opponent (27 .6%); (3) challenge a higher-ranking individual while seated next to o r in the general area of (and/or grooming) an even higher-ranking anim al and then enlist their support against the former (13.4%); and (4) c hallenge a higher-ranking animal when an adult male is in the area and enlist support of the male (1.8%). The use of the above strategies wa s not affected by age group or sex. The main points of interest are th at juvenile sooty mangabeys do move up the dominance hierarchy using a variety of behavioural patterns and that this is accomplished without aid from matrilineal kin. (C) 1995 The Association for the Study of A nimal Behaviour