SEXUAL-BEHAVIOR OF MATERNALLY SEPARATED GIBBONS (HYLOBATES)

The effect of early maternal separation on the sexual behavior of capt ive gibbons was investigated because (a) maternal separation compromis e sexual behavior of some nonhuman primates and (b) adequate sexual be havior is essential to species propagation. Most of the maternally sep arated gibbons (24/31) were sexually proficient. Sexual behavior overa ll did not differ significantly in relation to species, sex, origin (w ild- vs. captive-born), or type of rearing facility (home vs. zoo). Se xual proficiency was not related to the age at separation from the mot her, but it was associated with introduction within 19 months of age t o a conspecific of less than 3 years of age and an absolute age differ ence of less than 2 years. Sexual proficiency was associated with rear ing and adult housing in relatively large enclosures. Gibbons that wer e isolated from conspecifics between 6 months and 2 years of age were strongly attached to humans, but this did not prevent sexual proficien cy. A greater proportion of males than females were adversely affected sexually by prolonged early social isolation. Inadequate sexual behav ior was associated with fearfulness of conspecifics, which probably in terfered with compatible social relationships, including duetting. Ina dequate sexual behavior was but one aspect of a mor general behavioral deficiency resulting from inadequate early socialization. Early mater nal separation in gibbons is compatible with species-typical sexual be havior under the conditions described above. It is not necessary for g ibbons to learn sexual and parental behavior by observing experienced adult conspecifics. (C) 1997 John Wiley & sons, Inc.