Age at sexual maturity of males and timing of the mating season of polar bears (Ursus maritimus) in Greenland
Age at sexual maturity among male polar bears (Ursus maritimus) and timing of the mating season were studied by microscopic and macroscopic analysis of the reproductive organs from 165 male and 92 female Greenland polar bears. Males became sexually mature in the spring following their fifth birthday. Testes sampled during the spring reached 95% of […]
Female reproductive parameters in the Javan gibbon (Hylobates moloch)
Abstract Javan gibbons (Hylobates moloch) are one of the most endangered gibbon species in the world. Data on the reproductive biology of the species are almost nonexistent, and a general understanding of the female reproductive biology of this species is important for both ex situ and in situ conservation. Using 18 years of data from […]
Reproductive patterns in pygmy lorises (Nycticebus pygmaeus): Behavioral and physiological correlates of gonadal activity
Abstract 10.1002/zoo.10072.abs The purpose of this study was to evaluate behavioral and physiological parameters of reproduction in a breeding colony of pygmy lorises. To this end, nine male and eight female adult pygmy lorises were kept under natural lighting conditions and monitored through five consecutive breeding seasons. Behavioral data were collected continuously throughout the year […]
Lifetime semen production in a cheetah (Acinonyx jubatus)
Abstract 10.1002/zoo.1034.abs Lifetime semen production data provide valuable insight into a species’ natural history and biology as well as information about the potential fertility of males at various life stages. An understanding of the ages of sexual maturity, peak sperm production, and gonadal senescence will contribute to the design of species management plans for captive, […]
Reproductive biology of captive Arabian oryx (Oryx leucoryx) in Saudi Arabia
Abstract 10.1002/(SICI)1098-2361(1996)15:43.3.CO;2-P Reproductive data on captive Arabian oryx (Oryx leucoryx) were collected from June 1986 through April 1992 at the National Wildlife Research Center (Taif, Saudi Arabia). Oryx females are polyestrous. The estrous cycle averaged 22 days and mean gestation length was 260 ± 5.5 days (S.D). Sex ratio at birth was unbiased and mean […]
Reproduction of the lesser kudu (Tragelaphus imberbis) at Dvůr Králové Zoo
Abstract 10.1002/zoo.1430110205.abs Reproductive data on captive lesser kudus (Tragelaphus imberis) were collected from 1972 to 1990. The estrous cycles of two females were 21 and 22 days. Mean gestation length of 18 pregnancies was 244 ± 5.5 days (range = 235–256 days), and 71.2% of interbirth intervals (n = 146) were from 248 to 365 […]
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 […]
Reproductive parameters of clouded leopards (Neofelis nebulosa)
Abstract 10.1002/zoo.1430080303.abs Reproductive data compiled from the International Clouded Leopard Studbook revealed that 75% of all litters were born to females between one and five years of age. Sixty-three percent of the males had sired litters by four years of age with reproduction declining after six years of age. Sixteen zoological institutions surveyed worldwide contributed […]
Life-History Patterns of Cuban Poeciliid Fishes (Teleostei: Cyprinodontiformes)
The following work provides basic information about the life history of 10 Cuban species of the family Poeciliidae. Adult fish stocks were captured in their natural habitat, and litters obtained from them were raised and maintained in captivity for 19 weeks. For each species, we present the mean value of newborn length (TLo), age at […]
Hormonal correlates of development and natal dispersal in wild female owl monkeys (Aotus azarae) of Argentina
Pair-living and socially monogamous primates typically do not reproduce before dispersing. It is currently unclear whether this reproductive suppression is due to endocrine or behavioral mechanisms. Cooperatively breeding taxa, like callitrichids, may forego reproduction in natal groups because they reap inclusive fitness benefits and/or they are avoiding inbreeding. However, neither of these benefits of delayed […]