Reproductive biology of female titi monkeys (Callicebus moloch) in captivity

Titi monkeys (Callicebus spp., Cebidae) are monogamous neotropical primates that live in family-like groups typically consisting of an adult monogamou s pair and one or two young. Knowledge about the reproductive biology of th is genus is scanty. This study investigated the reproductive biology of fem ale dusky titi monkeys (Callicebus moloch). An initial analysis characteriz ed reproductive parameters of 32 females from a captive colony maintained f or 23 years at the California Regional Primate Research Center (CRPRC), The colony records provided data on reproductive parameters such as interbirth intervals, seasonality, age at first pregnancy, and reproductive rate in c aptivity, Changes in urinary levels of estrone conjugates (E1C) and pregnan ediol-3alpha-glucuronide (PdG;) were used to characterize major reproductiv e events. Urine samples from eleven females were collected during 17 months . The endocrine data were used to examine changes associated with cycling, conception, and the post-partum period as well as to determine the duration of the ovarian cycle and gestation length. The analysis of colony records indicated that females whose infant survived through weaning gave birth at intervals remarkably close to one year, while those who lost their offsprin g showed a significantly shorter interval, As long as they Lived within the family group, mature female offspring did not breed. The analysis of the e ndocrine profiles indicated that after giving birth to a viable offspring, females undergo a relatively prolonged period of anovulation (approx. 6.5 m onths), followed by 1-3 non-conceptive cycles (approx, 1 month), after whic h they conceive and gestate (4.3 months). Am. J. Primatol, 47:183-195, 1999 . (C) 1999 Wiley-Liss, Inc.