 They are primarily arboreal and most are restricted to humid forests, but the Zanzibar red colobus prefers coastal thickets and scrub.Red colobuses are highly sensitive to hunting and habitat destruction, and have been referred to as probably the most threatened taxonomic group of primates in Africa.If following the taxonomic treatment advocated in "Mammal Species of the World", all species except the Central African red colobus are assessed by the IUCN as endangered or critically endangered.