史密森尼保護(hù)生物學(xué)研究所物種生存中心 (CSS) 的科學(xué)家們正在通過研究異地條件如何影響繁殖來拯救獵豹。

最近，CSS 科學(xué)家發(fā)現(xiàn)，與住在遠(yuǎn)離人類的寬敞繁殖中心的雄性相比，將獵豹暴露于傳統(tǒng)的公共展覽以及三個(gè)以上的照顧者會減少精子輸出（每次射精的活動精子總數(shù)）和整體行為活動。在野生貓科動物中，沒有關(guān)于雄性數(shù)量對群體成員生殖生理或激素指標(biāo)影響的數(shù)據(jù)。研究人員考慮了雄性獵豹在異地條件下如何分組（或不分組）的可能性可能會影響射精質(zhì)量或睪丸激素和糖皮質(zhì)激素（壓力激素）譜。

自由放養(yǎng)的獵豹的社會結(jié)構(gòu)與其他貓科動物大不相同。野生雌性是獨(dú)居的，只在短暫交配或照顧后代時(shí)與其他獵豹在一起。相比之下，男性可以作為單身人士生活，但通常在稱為聯(lián)盟的永久、緊密聯(lián)系的群體中生活。聯(lián)盟通常由兩到三只動物組成，但最多可以有五只。這些獵豹如何在自然界中存在和生存提供了有關(guān)如何管理該物種在異地（圈養(yǎng)）收藏中繁衍生息的線索。

從歷史上看，在傳統(tǒng)城市動物園管理的獵豹繁殖成功率很低。雖然大多數(shù)成年雌性獵豹都是單獨(dú)飼養(yǎng)的（就像它們生活在野外一樣），但其中只有大約 25% 曾經(jīng)繁殖過。成功繁殖成年雄性的比例甚至更低，約為 18%。目前，大約 85% 的動物園飼養(yǎng)的雄性獵豹以小型聯(lián)盟的形式進(jìn)行管理，這是一種吸引人的策略，因?yàn)樗７铝艘吧鐣Y(jié)構(gòu)，并且動物群體為公眾創(chuàng)造了更有趣、更令人興奮的展品。

該項(xiàng)目探討了單身與聯(lián)合管理結(jié)構(gòu)在射精質(zhì)量和性腺 - 腎上腺激素濃度和概況方面的關(guān)系。在給定的獵豹群體中，研究人員還使用行為互動尋找社會等級的證據(jù)，然后將行為等級與繁殖指標(biāo)進(jìn)行比較。結(jié)果可能為群體管理和行為評估的影響提供實(shí)用見解，以提高這種稀有且難以繁殖的物種的保護(hù)育種效率。

這項(xiàng)研究的結(jié)果提供了進(jìn)一步的證據(jù)，表明強(qiáng)加于異地獵豹的生活條件可以深刻影響精液質(zhì)量。具體而言，CSS 研究人員取得了多項(xiàng)發(fā)現(xiàn)，首先是在聯(lián)盟結(jié)構(gòu)中管理獵豹具有精子輸出優(yōu)勢。最多數(shù)量的活動精子是由聯(lián)合雄性產(chǎn)生的，而不是由單身雄性產(chǎn)生的，并且來自同一組內(nèi)的多個(gè)雄性產(chǎn)生了優(yōu)良的射精。其次，有一些證據(jù)表明聯(lián)盟較高的精子質(zhì)量值與同時(shí)升高的組睪酮濃度之間存在關(guān)系。此外，很明顯，單身和聯(lián)合之間的差異不受糖皮質(zhì)激素下分組的腎上腺激素的調(diào)節(jié)。盡管雄性獵豹在集中的異地管理下生活在聯(lián)盟中具有精子輸出優(yōu)勢，但更多數(shù)量的活動精子不一定是由性腺雄激素或腎上腺糖皮質(zhì)激素產(chǎn)生的差異或所測量的行為驅(qū)動的。

合作者和合作伙伴

物種生存保護(hù)中心 (C2S2)
迪克森公園動物園
費(fèi)城動物園
圣地亞哥野生動物園
白橡樹保護(hù)
野生動物園
野人
William H. Donner Foundation Inc.
喬治梅森大學(xué)

出版物：
科斯特等人 2015a。異地管理的雄性獵豹（Acinonyx jubatus）的活動精子輸出受公眾暴露和護(hù)理人員數(shù)量的影響。 PLoS 一 10，e0135847。
科斯特等人。 2015b。群體管理影響雄性獵豹（Acinonyx jubatus）的生殖功能。生殖、生育和發(fā)育。
項(xiàng)目人員
Adrienne E. Crosier 博士
David E. Wildt 博士
項(xiàng)目新聞
2018 年 9 月 6 日
七只獵豹幼崽健康成長
2015 年 9 月 30 日
獵豹精子質(zhì)量
相關(guān)動物
獵豹
獵豹

Does Group Management of Male Cheetahs Influence Reproductive Fitness?

Scientists at the Smithsonian Conservation Biology Institute's?Center for Species Survival (CSS)?are working to save cheetahs by studying how ex situ conditions impact reproduction.

Recently, CSS scientists discovered that exposing cheetahs to traditional public exhibits as well as to more than three caregivers reduces sperm output (the total numbers of motile spermatozoa per ejaculate) and overall behavioral activity compared with males housed in spacious breeding centers away from people. There are no data in wild felids on the influence of number of males on reproductive physiology or hormone metrics of cohort members. Researchers considered the possibility that how male cheetahs were grouped (or not) under ex situ conditions could influence ejaculate quality or testosterone and glucocorticoid (stress hormone) profiles.

Free-ranging cheetahs have a social structure that is mostly different from other felid species. Wild females are solitary, and are with other cheetahs only during brief periods of mating or when caring for offspring. By contrast, males can live as singletons, but often range in permanent, closely bonded groups called coalitions. Coalitions are usually made up of two to three animals, but can have as many as five. How these cheetahs exist and survive in nature provides clues on how the species should be managed to thrive in ex situ (captive) collections.

Historically, cheetahs managed in traditional urban zoos experience poor reproductive success. While most adult female cheetahs are maintained singly (as they would live in the wild), only about 25 percent of these have ever reproduced. The proportion of successfully reproducing adult males is even lower at about 18 percent. Currently, about 85 percent of zoo-held, male cheetahs are managed in small coalitions, an appealing strategy because it mimics wild social structure, and animal groups create more interesting, exciting exhibits for the public.

This project explored the relationships between a singleton versus coalition management structure on ejaculate quality and gonadal–adrenal hormone concentrations and profiles. Within a given cheetah group, researchers also looked for evidence of social hierarchy using behavioral interactions followed by comparing behavioral rank to reproductive metrics. Results may provide practical insights on the influence of group management and behavioral assessments to improve conservation breeding effectiveness for this rare and difficult-to-reproduce species.

The findings from this study provided further evidence that living conditions imposed on cheetahs ex situ can profoundly influence seminal quality. Specifically, CSS researchers made several discoveries, the first that there were sperm output advantages for managing cheetahs in a coalition structure. The highest numbers of motile spermatozoa were produced by coalition males rather than singletons, and multiple males from within the same group produced?superior ejaculates. Second, there was some evidence of a relationship between the higher sperm quality values for coalitions and simultaneously elevated group testosterone concentrations. Further, it was clear that the differences between singletons and coalitions were not being regulated by the adrenal hormones grouped under glucocorticoids. Although there were sperm output advantages for male cheetahs to live in a coalition while under intensive, ex situ management, the greater numbers of motile spermatozoa were not necessarily being driven by differences in gonadal androgen or adrenal glucocorticoid production or to the behaviors measured.

Collaborators and Partners

Conservation Centers for Species Survival (C2S2)
Dickerson Park Zoo
The Philadelphia Zoo
San Diego Safari Park
White Oak Conservation
Wildlife Safari
The Wilds
The William H. Donner Foundation Inc.
George Mason University

Publications:?

Koester et al 2015a. Motile sperm output by male cheetahs (Acinonyx jubatus) managed ex situ is influenced by public exposure and number of care-givers. PLoS ONE 10, e0135847.

Koester et al. 2015b. Group management influences reproductive function of the male cheetah (Acinonyx jubatus). Reproduction, Fertility and Development.