 In addition to sustenance, evidence suggests that chimpanzees prey on red colobus to reinforce social status, as well as to attract sexual partners.When under attack, the red colobus males congregate to defend their group, while the females gather their infants and try to escape.Larger groups of red colobuses have an increased likelihood of attracting chimpanzees, but they also tend to have more defending males, making it harder for chimpanzees to hunt successfully.