Drill  (Mandrillus leucophaeus)

Frugivorous: Fruit eating/ fruit eater.
Natal: Site of birth
Oestrus: The time of ovulation (release of an egg from the ovary) in female mammals, when the female becomes receptive to males, also known as 'heat'.
Sexual dimorphism: When males and females of the same species differ in appearance.
Subspecies: A different race of a species, which is geographically separated from other populations of that species.

1. IUCN Red List (March, 2008)
   http://www.iucnredlist.org
   
2. CITES (September, 2002)
   http://www.cites.org
   
3. Meckes, K. (1999) The endangered Mandrillus leucophaeus: behaviour leading to extinction. The Emory Anthropologist, 0: 0. Available at:
   http://www.emory.edu/COLLEGE/ANTHROPOLOGY/EA/meckes.html
   
4. Primate Info Net (August, 2002)
   http://www.primate.wisc.edu/pin/factsheets/mandrillus_leucophaeus.html
   
5. Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford, U.K..
   
6. Bioko Biodiversity Protection Programme (September, 2002)
   http://www.bioko.org/primates/leucophaeus.asp
   
7. UNEP-WCMC species page (March, 2008)
   http://www.unep-wcmc.org/species/data/species_sheets/drill.htm