Abstract # 114:

Scheduled for Friday, August 18, 2006 11:15 AM-11:30 AM: Session 10 (Regency East #2) Oral Presentation

Grooming Serves Social Function in Sifaka (Propithecus verreauxi) in Kirindy Forest, Madagascar

R. J. Lewis1,2 and A. D. Gosselin-Ildari1
1University of Texas, 1 University Station C3200, Department of Anthropology, Austin, TX 78712, USA, 2Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, University of Texas M. D. Anderson Cancer Center, Bastrop, Texas 78602, USA
     Allogrooming in lemurs has been suggested to be fundamentally different from that of anthropoids. One reason is that lemurs generally rely on oral rather than manual grooming. Lemur grooming has also been suggested to serve less of a social function than has been attributed to anthropoid grooming. In order to test this hypothesis, we analyzed the grooming behavior of 32 Verreaux's sifaka living in 6 social groups in the Kirindy Forest of Madagascar. Based upon 1586 observation hours, we found that sifaka, like anthropoids, spend very little time mutual grooming (mean = 9%+/-11SD). They groomed more in the rainy season than the dry season (p < 0.001), suggesting that hygiene may indeed be a reason for grooming. However, as in anthropoids, hygiene was not sufficient to explain grooming patterns. Half of all allogrooming involved parts of the body that could have been easily groomed by the recipient, such as the limbs. Grooming rates were correlated with rank (p < 0.005), with low-ranking individuals grooming the most, and sex (p < 0.003), with males grooming more. Moreover, the mating season occurs during the rainy season. Grooming rates were significantly higher in the mating season than the birth season (p < 0.005). These results suggest that grooming in sifaka may have an important social function as in anthropoids, despite the physical difference in how it is performed. Supported by NSF DIG (#0002570), Wenner-Gren, Leakey Foundation.