The Central African red colobus monkey (Piliocolobus foai) occupies tropical forest habitat, where it lives in large groups of up to 50 individuals. The group constellations are somewhat fluid with individual monkeys moving between groups, especially in their adolescence. Thus, not all individuals in a group are directly related to each other. Females usually outnumber the larger males, which can weigh up to 25 pounds, but young males occasionally form small bachelor groups. A strong dominance hierarchy within each group determines access to the best food sources and mating opportunities. Females give birth to a single offspring every other year. Red colobus use their long tails for balance as they move through the forest canopy feeding on leaves and fruit. The species is very vulnerable to disturbance, hunting and habitat loss. Natural predators of red colobus include eagles, leopards and astonishingly, chimpanzees, which have perhaps the largest impact on red colobus populations wherever the two species coexist.