Feeding behavior of yellow baboons (Papio cynocephalus): relationship to age, gender and dominance rank.

This paper examines the relationship of age, gender and dominance rank to certain quantitative measures of food intake and diet among free-living. Amboseli baboons (Papio cynocephalus). Adult males and adult females showed no significant difference in proportion of time spent feeding although the two classes differed markedly in body weight and hence basal metabolic rate. Among adults, individuals of high, middle and low dominance status showed no consistent differences in proportion of time spent feeding. However, within the group as a whole and among adult males, high ranking individuals generally had longer feeding bout durations than lower ranking individuals. Also, high ranking individuals were less likely to have their feeding bouts aggressively interrupted than were lower ranking individuals and those individuals whose feeding bouts were most frequently interrupted showed the lowest mean feeding bout duration. Application of the Kaplan-Meier (1958) statistical procedure to these data on feeding bout duration showed that the reduction in expected bout duration due to disruptive social factors was proportionately greater among low ranking individuals than among higher ranking individuals. Quantitative analysis of dietary overlap showed that individuals of all age-sex classes except adult males had a greater degree of overlap with members of their own class than with members of other classes. Pairs of closely-ranked individuals showed greater dietary overlap than did pairs of individuals occupying more disparate rank positions. Alternative behavioral strategies for minimizing interference from high ranking individuals and at the same time assuring adequate food intake are discussed.