DO FEMALE CHACMA BABOONS COMPETE FOR A SAFE SPATIAL POSITION IN A SOUTHERN WOODLAND HABITAT

In this study troop of chacma baboons (Papio cynocephalus ursinus) at Mkuzi Game Reserve, Zululand, South-Africa, it is suggested that risk of predation and competition over safe spatial position had more impor tance and effect on female behaviour than did competition for food. On ly 6.4% of all agonistic events were over food patches and no signific ant correlation was found between a female's dominance rank and propor tion of time spent feeding, feeding bout length or diet composition. P arameters of reproductive success, such as inter-birth intervals and i nfant mortality were not correlated with female dominance rank. Female mortality, however, was related to dominance rank and all of the five females who disappeared during the study were low-ranking. Four of th e five females disappeared after troop fission. There is circumstantia l evidence supporting the suggestion that predation by leopards is the main cause of mortality of females at Mkuzi. High levels of female ag gression were recorded, with almost no occurrences of support coalitio ns. Most of the aggression took place among similar ranking females, o r was directed by the top ranking toward the lowest ranking females. M ost of the female-to-female agonistic encounters were in a social cont ext, and more than half were over a spatial position next to other adu lt troop members. Aggression among females increased after troop fissi on. It is suggested that the higher-ranking females may be better prot ected from predation, through access to more central spatial positions in the troop. Indeed, a positive correlation was found between a fema le's dominance rank and the time spent next to other adult troop membe rs. It may be that avoiding food competition by keeping larger distanc es from others, while foraging, was translated in lower ranking female s to a cost of higher predation risk.