Captive Births Research Articles

Species of wild animals bred in captivity during 1991 and multiple generation captive births

Species of wild animals bred in captivity during 1991 and multiple generation captive births

Sources of Variation in Estimating Litter Characteristics of the Garter Snake, Thamnophis elegans

--Studies of snake demography usually involve the estimation of litter size and neonate size, but potential sources of variation resulting from the methods used to obtain this information are rarely considered. Using data from four populations of Thamnophis elegans, we found that estimates of litter size obtained by holding gravid snakes in captivity were less variable when dead young or undeveloped eggs were included rather than excluded; we recommend that all components of litters be reported in future studies. Litter sizes obtained by palpation of gravid snakes in the field were similar to estimates from captive births in two of three populations we examined, but not the third. There was some evidence that litters from longer-term captives were more likely to contain dead young, and, in one population, smaller young. Access to substrate heat by gravid snakes was correlated with smaller progeny in another population. In general, captive-born snakes were smaller than neonates born in the field, but some growth may have occurred in the latter. Factors that might influence the size of snakes born in captivity are temperature, feeding level of mother, and stress; in order to minimize their potential effects, we recommend that gravid snakes be held for as short a time as possible. The study of life history variation in snakes has lagged behind that of other kinds of organisms (Parker and Plummer, 1987), mainly because of the difficulties of sampling snake populations (Turner, 1977). Although field measurements of important parameters such as survivorship have rarely been measured adequately (Parker and Plummer, 1987), reports of clutch or litter size are abundant (Seigel and Ford, 1987). These data can be obtained by dissection of preserved specimens, gentle hand palpation of gravid snakes in the field, or holding gravid snakes in captivity until they have laid eggs or produced young. The accuracy of clutch or litter size estimates obtained by palpation is unclear, but with practice, embryos can usually be distinguished from one another and from lumps of fecal material within the large intestine (Fitch, 1987; Farr and Gregory, pers. obs.). Sometimes, especially in the later stages of gestation, embryos may be more difficult to distinguish from one another; an embryo and its yolk sac may also be felt as two separate lumps (Fitch, 1987). Difficulties such as these will influence estimates of litter

First birth in captivity of the Sun‐tailed guenon: Cercopithecus solatus Harrison 1988: a recently discovered species

First birth in captivity of the Sun‐tailed guenon: <i>Cercopithecus solatus</i> Harrison 1988: a recently discovered species

Species of wild animals bred in captivity during 1988/1989 and multiple generation captive births

Species of wild animals bred in captivity during 1988/1989 and multiple generation captive births

First birth in captivity of the Sun-tailed guenon: Cercopithecus solatus Harrison 1988: a recently discovered species

First birth in captivity of the Sun-tailed guenon: Cercopithecus solatus Harrison 1988: a recently discovered species

Species of wild animals bred in captivity during 1988/1989 and multiple generation captive births

Species of wild animals bred in captivity during 1988/1989 and multiple generation captive births

Species of wild animals bred in captivity during 1987 and multiple generation captive births

Species of wild animals bred in captivity during 1987 and multiple generation captive births

Captive breeding of the cheetah (Acinonyx jubatus) in North American zoos (1871–1986)

AbstractThe African cheetah has been bred in North American zoological facilities since 1956. The captive population has since grown to around 200 animals because of a combined increase in importation plus captive births. From 1982 to 1986, the captive birth rate declined by 50%, primarily because of a low frequency of breeding individuals in the population. The 1986 population had an effective breeding size of 28.1 in a total population of over 193 cheetahs. The incidence of infant mortality has been high (36.7%) relative to other zoo‐bred species, perhaps as a consequence of the previously observed genetic impoverishment of the species. The combination of low fecundity, high infant mortality, and population dynamics indicates that the North American captive cheetah population is neither a self‐sustaining nor a theoretically “viable population” as defined by Soule et al. [ZOO BIOLOGY 5:101–114, 1986]. Possible recommendations for improving captive cheetah propagation are discussed.

Species of wild animals bred in captivity during 1986 and multiple generation captive births

Species of wild animals bred in captivity during 1986 and multiple generation captive births

Species of wild animals bred in captivity during 1987 and multiple generation captive births

Species of wild animals bred in captivity during 1987 and multiple generation captive births

Species of wild animals bred in captivity during 1985 and multiple generation captive births

species of wild animals bred in captivity during 1985 and multiple generation captive births

Species of wild animals bred in captivity during 1986 and multiple generation captive births

Species of wild animals bred in captivity during 1986 and multiple generation captive births

Species of wild animals bred in captivity during 1984 and multiple generation captive births

International Zoo YearbookVolume 26, Issue 1 p. 411-411 Species of wild animals bred in captivity during 1984 and multiple generation captive births First published: January 1987 https://doi.org/10.1111/j.1748-1090.1987.tb03182.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume26, Issue1January 1987Pages 411-411 RelatedInformation

Species of wild animals bred in captivity during 1985 and multiple generation captive births

species of wild animals bred in captivity during 1985 and multiple generation captive births

Maternal Effects on Body Size of Large Insular Peromyscus maniculatus: Evidence from Embryo Transfer Experiments

Adult Peromyscus maniculatus gambelii from mainland California are significantly smaller than P. m. santacruzae from Santa Cruz Island, California, whether they are captured in the wild or raised from birth in captivity. The two subspecies also differ significantly in weight as neonates. Results from the experimental transfer of 4-day old P. m. gambelii embryos into P. m. santacruzae foster mothers demonstrate that the average neonatal weight of P. m. gambelii offspring increases significantly if they are borne and delivered by P. m. santacruzae foster mothers. This apparent prenatal non-genetic maternal influence on neonatal body size does not appear to be caused by differences in gestation period or average litter size, or by a genetic bias in the donor sample. Although the transferred offspring were large at birth, and were nursed by the large P. m. santacruzae foster mothers, they were relatively small (equivalent to other P. m. gambelii) at maturity. The results of our experimental studies are concordant with predictions from quantitative genetic studies on laboratory mice.

Species of wild animals bred in captivity during 1984 and multiple generation captive births

Species of wild animals bred in captivity during 1984 and multiple generation captive births

Species of wild animals bred in captivity during 1982/1983 and multiple generation captive births

species of wild animals bred in captivity during 1982/1983 and multiple generation captive births

Immunoreactive luteinizing hormone, estradiol, progesterone, testosterone, and androstenedione levels during the breeding season and anestrus in Siberian tigers.

Seasonal analysis of 1239 captive births of Siberian tigers (Panthera tigris altaica) indicated a peak in April to June (P less than 0.001). Studies on seven animals in Minnesota indicated that behavioral heat cycles and ovarian follicular phase cycles began in late January and ceased in early June. Behavioral observation of 12 heat cycles in four tigers yielded an estrous length of 5.3 +/- 0.2 days and an interestrous interval of 25.0 +/- 1.3 days. Hormone assays on weekly blood samples (N = 180) from three female tigers indicated 16 cycles in two breeding seasons. Peak estradiol-17 beta levels were 46.7 +/- 6.0 pg/ml (N = 17) and interestrous concentrations were 8.7 +/- 0.66 pg/ml (N = 28) during the breeding season. Anestrous estradiol levels were 4.2 +/- 0.5 pg/ml (N = 70). The interestrous interval between estradiol peaks was 24.9 +/- 1.3 days (N = 9) with two outliers of 42 days. Serum progesterone concentrations from February to June were 1.2 +/- 0.15 ng/ml (N = 32), providing no evidence for ovulation or corpus luteum formation. Luteinizing hormone (LH) levels were 0.56 +/- 0.04 ng/ml (N = 180). Serum testosterone (r=0.71, P less than 0.001) and androstenedione levels (r=0.75, P less than 0.001) were correlated with estradiol during the breeding season. The duration of anestrus was 8 mo in two of these tigers. The interval was shortened in one tiger by exposure to a 16L:8D photoperiod. The Siberian tiger appears to be a polyestrous seasonal breeder and an induced ovulator whose breeding season may be synchronized by photoperiod.

Behavioural ecology and communication in the Cape grysbok

The behaviour of the Cape grysbok, a small antelope inhabiting the fynbos vegetation of the southern and western Cape, is descriptionbed. Three wild grysbok males, fitted with radio transmitters, were observed to remain within well-defined ranges which averaged 2,5 ha in area. These ranges were evidently defended territories, but no incidences of active territorial defence were observed. Wild grysbok spent an average of 50% of the day active and 50% inactive during winter. Fighting between captive males tended to escalate rapidly to damaging levels, and threat displays were relatively unimportant. In courtship behaviour tactile and olfactory communication were prominent, but visual displays were poorly developed. Scent marking with the preornital glands was frequent in males but rare in females. Marking was associated with agonistic encounters between males, and also tended to occur in response to novel environments. Dominant males marked more frequently than subordinates. The frequency of preorbital marking and courtship behaviour in males varied seasonally, reaching a peak in the main conception period. The distribution of births in captivity showed a peak in spring.

Species of wild animals bred in captivity during 1981 and multiple generation captive births

International Zoo YearbookVolume 23, Issue 1 p. 263-263 species of wild animals bred in captivity during 1981 and multiple generation captive births First published: January 1984 https://doi.org/10.1111/j.1748-1090.1984.tb03048.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume23, Issue1January 1984Pages 263-263 RelatedInformation