Excessive light sensitivity in Papio papio: its variation with age, sex, and geographic origin.

Excessive sensitivity (levels 3 and 4) in a population of 1,122 Papio papio was related with age, sex, and geographical origin. (1) Age. There was no clinical response to intermittent light stimulation under the age of 5 months. These was no difference between animals 6 months to 2 years (J1) and those aged 2 to 4 years (J2). Adult females were less often light sensitive (levels 3 and 4 = 32.9%) than immature females (52.4%). Adult males could usually not be tested, but were probably less often sensitive than immature males. (2) Sex. Immature females (J1 + J2) were more often light sensitive (52.4%) than immature males (38.1%). (3) Geographical origin. No animals from East Senegal (Sansande Region) were very light sensitive. Animals from Casamance were more often light sensitive (56.2%) than those from the Niokolo-Koba National Park (N.K.N.P.) (20%). Of two samples taken at one spot between these two regions, one group resembled the population from Casamance and the second resembled that from the N.K.N.P. This observation raises several questions about the respective roles of genetic, ecological, and ethological factors.