Although chimpanzees (Pan troglodytes) are most commonly associated with forested habitats in Africa, there are several countries in both West and East Africa where chimpanzee populations inhabit savannas. This implies that the habitats are more open, with higher temperatures and lower annual rainfall, which has required different adaptive strategies from the chimpanzees living there.  Savanna chimpanzees are taxonomically identical to forest-dwelling chimpanzees, and thus comparisons of the behavior, morphology and ecology of the two groups help researchers to understand how early humans may have adapted, millions of...