Ecological constraints on group size in baboons

Systems models of the behavioural ecology of two genera of baboons (the galada Theropithecus gelada and the common baboon Papio sp.) are compared. Ambient temperature turns out to be the most important factor influencing both taxa's time budgets. However, their feeding and travel time required respond in complementary ways to gross changes in climate conditions. The models are used to calculate habitat-specific maximum ecologically tolerable group sizes for each taxon. They vary considerably across habitats, with the two taxa having complementary geographical distributions. This analysis suggest that populations may differ in both the structure of their groups and individual animal's preferred reproductive strategies in ways that appear to be random, but which are in fact closely determined by environmental conditions. -from Author