Trigger of twin-fights in captive common marmosets
Abstract Common marmosets usually give birth to twins and form a social group consisting of a breeding couple and pairs of same-aged siblings. The twins may engage in the first agonistic fights between them, twin-fights (TFs), during adolescence. This study investigated the TFs based on records accumulated in our captive colony over 12 years to […]
Reproduction in captive Taiwan macaques (Macaca cyclopis) in comparison to other common macaque species
Abstract 10.1002/zoo.1430140405.abs Twenty-five years of reproductive and birth data from a Macaca cyclopis colony at the New England Regional Primate Research Center (NERPRC) indicate that these animals are seasonal breeders with a birth peak between February and May. Interbirth intervals have a mean of 587.5 ± 45.6 days. The age at first reproduction for females […]
Reproductive parameters of mandrills at the Tulsa Zoo
Abstract 10.1002/zoo.1430140205.abs The genital swelling patterns and birth records of female mandrills housed at the Tulsa Zoo between 1979 and 1992 were examined to determine various reproductive parameters. Mean age at first adolescent genital swelling was 2.7 years (sd = .55), first adult swelling was 3.7 years (sd = .64), and first conception was 5.1 […]
Reproductive biology of captive and free-ranging spider monkeys
Abstract 10.1002/zoo.1430090102.abs Records from 42 zoos and from long-term studies of wild populations were analysed to describe the reproductive biology of spider monkeys (Ateles spp.). Both data sets suggested that spider monkey females typically have their first infant between 7 and 8 years of age with an interbirth interval of approximately 32–36 months. Infant sex […]
Status and reproductive potential of lion-tailed macaques in captivity
Abstract 10.1002/zoo.1430080503.abs Publication of a studbook for Macaca silenus in 1983 provides detailed demographic information on the captive North American population. These data indicate that females reach sexual maturity at about 4 years of age, whereas onset of reproduction for males occurs at age 5. One-third of all sexually mature females and 57% of sexually […]
The reproductive biology of female Père David’s deer (Elaphurus davidianus)
Abstract 10.1002/zoo.1430080107.abs Data for this study came from breeding records of 27 Père David’s (Elaphurus davidianus) hinds maintained in large pastures and from estrous records of four hand-reared nulliparous hinds. The mean estrous cycle length ranged from 17.5 to 19.6 days. Standing estrus resembled that of other cervids, except that a low, moaning vocalization was […]
Maternal Investment in Captive Giraffes
Sex-biased maternal investment involves differential allocation of resources to production and rearing of sons or daughters as a function of their anticipated reproductive output. We examined reproductive investment among captive giraffes (Giraffa camelopardalis) over a 21-year period to determine extent to which females invest differentially in offspring by sex. We found an unbiased sex ratio […]