Barnes S.A.,White Oak Conservation Center |
Andrew Teare J.,International Species Information System |
Staaden S.,Jacksonville Zoo and Gardens |
Metrione L.,South East Zoo Alliance for Reproduction and Conservation |
Penfold L.M.,South East Zoo Alliance for Reproduction and Conservation
General and Comparative Endocrinology | Year: 2016
Basic reproductive information in female jaguars (. Panthera onca) is lacking, thus longitudinal fecal samples from seven females were analyzed via enzyme immunoassay to measure estradiol and progestin metabolites throughout the year. Mean estrus length of 194 estrus periods measured hormonally was 6.5 ± 0.3 d, mean peak fecal estradiol concentration was 138.7 ± 5.7 ng/g; and in one female, estrus resumption occurred approximately 15 d post-partum. Ovulation, as indicted by sustained elevated progestin concentrations (>20 d), was successfully induced one time by treatment with exogenous hormones in one female and by physical vaginal stimulation in two females a combined total of three times. Elevated fecal progestin was observed outside exogenous stimulation on five occasions, suggesting ovulation occurred spontaneously. Mean length of physically induced and spontaneous pseudopregnancies was 24.7 ± 4.2 d and 29.6 ± 2.6 d, respectively, and mean length of pregnancy (n = 2) was 98.0 ± 0.0 d. Mean peak progestin concentration for spontaneous and induced pseudopregnancies, and pregnancy was 7.4 ± 1.4 μg/g, 6.4 ± 1.2 μg/g, and 13.7 ± 1.0 μg/g, respectively. This data suggests jaguars are polyestrous and generally induced ovulators, with a moderate incidence of spontaneous ovulation. Additionally, two protocols to successfully stimulate ovarian activity in jaguars are described. © 2015 Elsevier Inc.
Tubbs C.W.,Institute for Conservation Research |
Moley L.A.,Institute for Conservation Research |
Ivy J.A.,San Diego Zoo Global |
Metrione L.C.,South East Zoo Alliance for Reproduction and Conservation |
And 4 more authors.
General and Comparative Endocrinology | Year: 2016
The captive southern white rhinoceros (SWR) population is not currently self-sustaining, primarily due to poor or absent reproduction of captive-born (F1+) females. In this study, we investigate the role of dietary phytoestrogens in this reproductive phenomenon by characterizing activation of SWR estrogen receptors (ESRs) 1 and 2 by diet items from nine North American institutions and comparing female SWR fertility to total diet estrogenicity. Of the diet items tested, alfalfa hay and soy and alfalfa-based commercial pellets were found to be the most potent activators of SWR ESRs. In contrast, most grass hays tested were not estrogenic. The estrogenicity of total diets varied across the institutions surveyed and the degree of diet estrogenicity was positively associated with the percentage of the total diet comprised by pellets. Comparisons of fertility records of the institutions surveyed showed no significant relationship between diet estrogenicity and fertility for female SWR conceived or born in the wild (F0). However, for F1+ females, there was a significant negative relationship between institutional diet estrogenicity and fertility. Taken together, these data suggest that developmental exposure to phytoestrogens may be the cause of poor fertility in captive-born female SWR. Whether the low fertility of the current population of captive-born female SWR is permanent or can be reversed by removing phytoestrogens from the diet remains unclear. However, our findings suggest that in order for the SWR population to become self-sustaining, the development and feeding of low phytoestrogen diets should be strongly considered. © 2016 Elsevier Inc.
Penfold L.M.,South East Zoo Alliance for Reproduction and Conservation |
Hallager S.,Smithsonians National Zoo |
Boylan J.,Dallas Zoo |
Boylan J.,University College West |
And 3 more authors.
Zoo Biology | Year: 2013
To better understand breeding conditions to promote reproduction in captive kori bustards, fundamental endocrine studies measuring fecal androgen metabolites in male and female kori bustards were conducted. Feces collected weekly from males and females were analyzed for testosterone using enzyme-linked immunoassay. Results from adult males (n = 5), adult females (n = 10), immature males (n = 10), and immature females (n = 10) revealed seasonally elevated testosterone concentrations in fertile, but not nonfertile adult males and females (P > 0.05). Adult females that were not maintained in a breeding group, or that did not produce eggs, did not demonstrate increases in testosterone compared to egg laying counterparts. In males, but not females, seasonal testosterone increases were accompanied by weight gain. Peaks in male fecal androgen metabolites ranged from 10- to 22-fold higher than nonbreeding season (181.5 ± 19.1 vs. 17.0 ± 0.94 ng/g; P < 0.05). Mean breeding season values for adult males were 83.6 ± 6.1 ng/g vs. nonbreeding season values of 12.3 ± 0.73 ng/g (P < 0.05). In females, average breeding season testosterone concentrations were approximately 4-fold higher than nonbreeding season (55.9 ± 6.0 vs. 14.5 ± 1.8 ng/g), with peaks 10- to 30-fold higher. Results show that noninvasive fecal androgen metabolite analysis can provide a means of predicting fertility potential of male and female kori bustards and might be utilized to assess effects of modifying captive environments to promote reproduction in this species. © 2012 Wiley Periodicals, Inc.
PubMed | South East Zoo Alliance for Reproduction and Conservation, San Diego Zoo Global, Mars Hill University and Institute for Conservation Research
Type: | Journal: General and comparative endocrinology | Year: 2016
The captive southern white rhinoceros (SWR) population is not currently self-sustaining, primarily due to poor or absent reproduction of captive-born (F
PubMed | South East Zoo Alliance for Reproduction and Conservation
Type: Journal Article | Journal: Zoo biology | Year: 2014
Zoos and other ex situ wildlife institutions can play an important role in species conservation by maintaining populations for education and research, as sources for potential re-introduction or reinforcement, and as ambassadors for financial support of in situ conservation. However, many regional zoo associations are realizing that current captive populations are unsustainable, with many programs failing to meet demographic and genetic goals to ensure long-term viability. Constraints on population size due to limited space often mandate delayed and/or less frequent breeding, but for females of many species this can have profound effects on fertility. A retrospective analysis combined with published literature and reliable anecdotal reports reveals that, when females are housed in a non-breeding situation for extended periods of time, reproductive changes that negatively impact fertility have occurred in multiple species, including canids, elephants, white rhinoceros, Sebas bats, wildebeest, stingrays, and some felid species. Competing space needs and changing interest in taxa for exhibits over time compound the problem. Counter strategies to breed early and often have their own demographic and genetic consequences as well as logistical and political implications. Strategies to mitigate the sustainability crisis in these taxa might include a mixed strategy in which young, genetically valuable females are bred earlier and at more regular intervals to ensure reproductive success, in combination with the judicious use of available tools to manage the number of offspring produced, including contraception and culling. An understanding of the issues at stake is the first step towards developing management strategies for sustainable populations.