The Dryas Monkey (Cercopithecus dryas), also known as Salonga Monkey or Ntolu, is a little-known species of guenon found only in the Congo Basin, restricted to the left bank of the Congo River. It has now been established that the animals previously classified as Cercopithecus salongo (common name Zaire Diana Monkey) were in fact Dryas Monkeys. Some older sources treat the Dryas Monkey as a subspecies of the Diana Monkey and classify it as Cercopithecus diana dryas, but it is geographically isolated from any known Diana Monkey population.

Its preferred habitat is believed to be secondary forest or the upper story of primeval forest. Dryas monkeys feed mainly on plant materials, primarily fruit, flowers and young leaves, though they will also take some invertebrates.

So far as is known, the Dryas Monkey is a fairly typical forest guenon. Body size varies from 40-55 cm, with a tail an additional 50-75 cm. Adults weight between 4 and 7 kg, with marked sexual dimorphism. Its markings are similar to those of the Diana Monkey, except that its lower back and forelimbs are greenish-grey in colour.

Group sizes range up to 30 individuals, with only a single adult male. Gestation period is 5 months, with normally a single infant being born. Sexual maturity is reached after 3 years. In captivity, a lifespan of up to 19 years has been recorded.

External links

• African Mammals Databank entry for the Dryas Monkey (http://www.gisbau.uniroma1.it/amd/amd305.html)

References

• Colyn, M., Gautier-Hion, A., & Vanden Audenaerde, D. T. (1991). Cercopithecus dryas Schwarz 1932 and C. salongo Vanden Audenaerde, Thys 1977 are the same species with an age-related coat pattern. Folia Primatologica, 56, 167-170.