AGE-RELATED-CHANGES IN THE NEUTRAL TAIL CARRIAGE OF ANUBIS BABOONS (PAPIO-ANUBIS)

Tail position and shape was measured in 253 photographs of 84 individually-identi-fiable anubis baboons (Papio anubis) in nonsocial or otherwise neutral situations. The proximal segment of the baboon tail was carried closer to vertical with each additional year of life, an average angular change of approximately 3° per year for males and 5° per year for females. Several features of tail shape also changed in relation to age. Age-related changes in the neutral tail carriage of anubis baboons were generally similar to those previously reported for yellow baboons (P. cynocephalus), and in both species, neutral tail carriage among adults was unrelated to dominance rank. These studies provide the basis of a potential technique for age estimation in wild primate populations and also provide a starting point for analysis of social communication through tail position. © 1979, Walter de Gruyter. All rights reserved.