- Latin Name: Allochrocebus preussi
- Bioko's Subspecies: Allochrocebus preussi insularis
- IUCN Status: Endangered
- Captive Population: None, according to ISIS.
Pruess's guenon is a high-altitude monkey that inhabits the Bioko highlands and Mt. Cameroon on the mainland. It is gray and black with a fluffy white bib below the face and a long curling tail. Preuss's guenons travel in small groups, foraging for fruits, seeds, leaves and flowers. Adult males have a blue scrotum.
On Bioko, Preuss's guenon is usually found above 800 m in montane forest. At lower elevations, it is replaced by the putty-nosed guenon. In the Caldera, however, BBPP has recorded Preuss’s guenons as low as 450 m. and putty-nosed as high as 1000 m.
Preuss’s guenon used to be the most common monkey on Pico Basile, but there is considerable evidence that it has been greatly reduced in the last ten years.
Cronin, D. T., D. Bocuma Meñe, T. B. Butynski, J. M. E. Echube, G. W. Hearn, S. Honarvar, J. R. Owens, and C. P. Bohome. 2010. Opportunities Lost: The Rapidly Deteriorating Conservation Status of the Monkeys on Bioko Island, Equatorial Guinea (2010). A Report to the Government of Equatorial Guinea by the Bioko Biodiversity Protection Program, Drexel University, Philadelphia, PA. 40pp.