Sooty mangabey males have also been observed to engage in infanticide. Estrus females tend to mate with multiple males, though sexual consortships can be formed. Female sooty and Tana River mangabeys have a postconception estrus, which may serve to confuse paternity, though a captive study showed sooty males to be able to tell the difference between a maximal fertile swelling and a postconception swelling. Mangabeys can live around 20-30 years, depending on the species. Humans and mangabeys can compete for the same wild food sources, and they are also hunted by humans for meat and killed as crop-raiding pests.
Black mangabeys are also prey for the crowned hawk eagle.
Deforestation is also a continuing problem. Agile mangabeys and Tana River mangabeys have very similar vocalizations. More is known about the sooty mangabey, a subspecies, than about the red-capped mangabey, the main species. Sooty mangabeys have powerful jaws that can be used to crack nuts that other monkeys cannot crack. Red-capped mangabeys are good swimmers.