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A PANORAMA OF PRIMATES Biologists concerned with the classification of the animal kingdom place apes and mon- keys in a taxonomic group called primates. This particular category is called an “order” and is the one which humans also belong to. As well as the more highly developed apes and monkeys, the primates include more primitive representatives, known as prosimians—the so-called lower primates—which show few similarities to humans. The primate order contains around 180 species and is broadly divided into two major divisions: the prosimians, or lower pri- mates, and the monkeys and apes, referred to as higher primates. The lower primates include lemurs, the aye-aye, bush babies, lorises, and tarsiers. The higher primates include all the other groups, from both the New World and Old World. Included are howler monkeys, capuchins, marmosets, baboons, and langurs; the lesser apes (the siamang and gibbons); the great apes (goril- las, chimpanzees, and orangutans); and, last, humankind. Almost all primate species are found in the tropical regions of the world. Rain forests dis- play the greatest diversity and abundance. The reason for this global distribution is linked with food and feeding. Although omnivorous, primates feed to a great extent on fruits, nuts, young leaves, and insects: equatorial and tropical regions offer these food supplies more or less year-round while they are seasonal in temperate regions. Exceptions to this gen- eralization include humans and two species of monkey—the Japanese macaque and the Barbary ape (the latter, despite its name, is a macaque, not an ape). The lifestyles of apes and monkeys are often described by the precise niche that they

Swamp forests in central and eastern Africa are home to the strange but elegant de Brazza’s monkey. The most striking aspect of this species is the ginger brow and the long, white beard.

L’Hoest’s monkeys live in montane forests of central Africa, their range overlapping with that of the mountain gorilla. Group sizes are small with a single dominant male in command.

occupy within their environment. None lives underground, and so they are characterized as either terrestrial—living on the ground— or arboreal—living in the trees. Some spe- cies can, quite happily, make the transition between the two zones, while others may be confined to one or the other through adapta- tions in anatomy and behavior. Throughout the evolution of apes and mon- keys, there has been a trend toward increas- ing brain size, both in relative terms and in absolute terms. With this has come increas- ing intelligence and an ability to learn. Apes and monkeys are social animals, and their social structure and behavior patterns have also become complex and varied, especially in advanced species such as the great apes. The development and maturity of young apes and monkeys have also become longer as the group has evolved, and as a consequence, their life spans have increased.

Following page: Large male mountain gorillas are often referred to as “silverbacks” for obvious reasons. This silverback will be the only fully mature male in his group, the focal point of their behavior and daily activity.

Male western lowland gorillas characteristically show the hair on the head slightly chestnut or ginger. This picture clearly shows the peaked head so typical of mature male gorillas.

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