Mandrill  (Mandrillus sphinx)

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'.

1. IUCN Red List (February, 2005)
   http://www.redlist.org
   
2. Animal Diversity Website (October, 2003)
   http://animaldiversity.ummz.umich.edu/accounts/mandrillus/m._sphinx$narrative.html
   
3. Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
   
4. CITES (October, 2003)
   http://www.cites.org
   
5. Burnie, D. (2001) Animal. Dorling Kindersley Limited, London.
   
6. Collins, H. (2001) Field guide to African Wildlife. HarperCollins Publishers, London.