Levels of affiliation between members of a captive family group of white-faced Saki monkeys (Pithecia pitheciay)

White-faced saki monkeys (Pithecia pitheciai are monogamous primates rarely studied in the wild. Little is known about their affiliative behavior. This study examined levels of affiliation between five members of a captive family group of white-faced saki monkeys at the St. Louis Zoo from October to November 2008. I collected twenty hours of data on the affiliative behavior of the five member group. This data consisted of focal animal samples, nearest neighbor focal animal samples, and interaction matrices of affiliative behaviors to determine the differences in levels of affiliation between male and female parent sakis, and male and female offspring. I found that male and female offspring tend to affiliate more than male offspring do with each other. The male parent rarely affiliated with his female offspring while the female parent affiliated with both her male and female offspring. The bonded pair affiliated infrequently and were rarely observed in proximity of each other (only 1 % of the observed time was spent in close proximity). These results differ from the findings of studies of the affiliative behaviors of the closely related titi monkeys (Callicebus sp.). Previous studies of captive titi monkeys show that affiliation tends to be higher between the bonded pair than between the parents and their offspring and that bonded pairs of titi monkeys display "jealousy behaviors" when intruders enter their group. The low level of affiliation between the white-faced saki bonded pair found in this study may be due to the fact that no new members have never been introduced to the family group at the St. Louis Zoo