May 14, 2000
White Handed Gibbons are in the Primate Order of the Hylobatidae Family of the lesser apes, in the Genus Hylobates (which includes all 11 species of gibbons) from the H. lar Species. (Rumbaugh, 1973) H. lar is found in the middle and upper stories of deciduous monsoon and evergreen rain forests of southern Burma, Thailand, the Malay Peninsula, Sunderland, and North Sumatra. (Rumbaugh, 1974) Gibbons are though to be magnamous although recent studies have documented individuals in the wild who mate with multiple partners. (Fuentes, 2000) This species has a co dominance where both the male and the female are dominant. (Gittins and Raemaekers, 1980) there is little to no sexual dimorphism and males and females are both socially and physically equal. Their family structure in made up of the "pair bonded" couple and their immature offspring. When the offspring reach sexual maturity they are driven out of the group by the parent of the same sex.
Although Gibbons are very territorial aggression and violence is very rare among H. lar. Their diets consist mainly of fruit (75%) and also include leaves, flowers, birds, and insects. (Richard, 1985) Although Gibbons have been documented to live in captivity p to 45 years wild population have a greatly reduced lifespan. (Rumbaugh, 1973) In this study I will attempt to show that captive White Handed Gibbons are more often groomed by other individuals rather than by themselves. This study will support the widely accepted notion that social grooming is used to reinforce the bonds between individuals (Ellefson, 1974) and is not for practiced for hygiene purposes. I observed two captive H. lar for this study: one male, one female. Both Gibbons where similar in body size: weighing about 15 pounds and roughly 3 feet tall. They each...