• fecal steriods;
  • spider monkeys;
  • Ateles ovarian cycle


An enzyme immunoassay (EIA) was applied to characterize the reproductive endocrinology of adult female black-handed spider monkeys (Ateles geoffroyi). Analysis of paired urine and fecal samples, collected from two females housed at San Diego Zoo, confirmed that the EIAs employed provided quantitative measurements of ovarian sex steroid hormones. Fecal metabolite levels were significantly correlated with those in urine, confirming that feces are a valid source of steroid metabolites in this species. The excretion of these metabolites in feces lagged urinary excretion by 1–2 days. The ovarian cycle profiles of the two captive females and five free-ranging females are comparable, with an average length of approximately 20–23 days. Cyclical bleeding, as previously reported, was observed in one of the two captive females. Pregnancy was detected in four free-ranging females, and early fetal loss for one female was indicated by hormonal data. Am. J. Primatol. 54:79–89, 2001. © 2001 Wiley-Liss, Inc.