• Mandrills (Madrillus sphinx) are a species of monkey inhabiting the forests of Gabon, Cameroon, Equatorial Guinea, and Congo on the west coast of Central Africa. They can be found in a variety of forested habitats including the tropical rainforests, but also riparian or montane forests. The monkeys spend their time in groups known as hordes that can be made up of dozens or even hundreds of members. Hordes have been documented spending time on cultivated farmland raiding crops when food is scarce.

    Adult male mandrills have a distinctive coloration on their faces that British biologist Charles Darwin described as “resplendent” and compared their coloration to “those of the most brilliant birds.” Females show a similar coloration, but it is dull rather than brilliant. This difference is a visually striking display of sexual dimorphism. Another dimorphous trait includes the impressive canine teeth present in the males, which have measured 6.5 centimeters (2.5 inches) in length. The males will use these when fighting over a mate and in hunting, although the diet of a mandrill consists of many more plants than it does animals.

    Mandrills face threats to the health of their population not only from deforestation but also from being hunted by humans for commercial bushmeat sale. Although they can climb trees, their body size—especially the larger males—makes it difficult to move through the tree canopy and escape from hunting raids.

    Lopé National Park—a tract of protected Congo basin rainforest in Gabon 4,910 square kilometers (1,900 square miles) in size—is an important habitat for populations of mandrills, Western lowland gorillas, and chimpanzees.

    1. Which physical traits of sexual dimorphism are present in mandrills? 

      Adult male mandrills are much larger than female mandrills. They can have a vibrant coloration of blues and reds on their faces and parts of their body. Male mandrills have large canine teeth that females do not have. These are some of the sexually dimorphic features present in male mandrills. 

    2. Why do some male mandrills have more colorful features than others?  

      Why do some male mandrills have more colorful features than others?  

    3. How many species of monkey are there?

      There are about 260 unique species of animals classified as monkeys. These species are further classified into different families of species, organized as Old World monkeys in Africa and Asia, and New World monkeys in the Americas. Monkeys are members of the taxonomic order of mammals called Primates, of which humans are also classified.   

  • Term Part of Speech Definition Encyclopedic Entry
    bush meat Noun

    meat acquired through the hunting of wild animals, particularly in Africa and Asia.

    canine (teeth) Noun

    one of four pointed, conical teeth situated on either side of the jaw of some mammals.

    canopy Noun

    one of the top layers of a forest, formed by the thick leaves of very tall trees.

    Charles Darwin Noun

    (1809-1882) British naturalist.

    deforestation Noun

    destruction or removal of forests and their undergrowth.

    dimorphic Adjective

    having two distinct forms.

    habitat Noun

    environment where an organism lives throughout the year or for shorter periods of time.

    Encyclopedic Entry: habitat
    horde Noun

    large crowd of people

    montane Adjective

    natural region defined by upland slopes and large conifers.

    resplendent Adjective

    shining brilliantly.

    riparian Adjective

    having to do with a river or stream.

    tropical rain forest Noun

    grouping of tall evergreen trees, usually close to the Equator, which receives more than 203 centimeters (80 inches) of rain a year.