Fecundity in the captive howler monkey,Alouatta caraya

Seven female Black howler monkeys, Alouatta caraya, from both wild- and captive-born origins have reproduced at Riverbanks Zoological Park. Three of the five wild-born females arrived as juveniles and grew to maturity; the other two were already mature upon arrival and reproduced shortly therafter. Two females which were born within the park's collection have since reached maturity and also reproduced. The interval between the first and second young of wild-born howlers is longer than between subsequent birth intervals. Subsequent young are also more precocious than their preceding siblings. In at least one case, a socially inferior female did not reproduce until placed within a different troop situation which elevated her social status. Females born in captivity conceived when 42 and 35 months old, the former situation being linked to low social status. Young born to females housed under both seasonal and regulated conditions of photoperiod demonstrated no difference in breeding intervals and seasonality of birth does not appear to be a factor in howler monkey reproduction.