ENDANGERED CALIFORNIA BIRD TO BE REINTRODUCED TO SKIES FOR FIRST TIME IN NEARLY 100 YEARS.

近百年来首次将濒危加州鸟类重新放归天空。

The San Diego Zoo Wildlife Alliance announced Thursday that two female critically endangered California condors had successfully hatched eggs without the help of male condors.

圣地亚哥动物园野生动物联盟周四宣布，两只极度濒危的雌性加州秃鹰在没有雄性秃鹰帮助的情况下已经成功孵化了卵。

The discovery of parthenogenesis, or asexual reproduction, was a first for the species and was achieved through the use of molecular genetic testing, the organization said.

该组织说，单性生殖或者说无性生殖的发现，是该物种的首次发现，这个发现是通过分子遗传测试实现的。

The event was detailed this week by the San Diego Zoo Wildlife Alliance's conservation scientists in the American Genetic Association's Journal of Heredity.

圣地亚哥动物园野生动物联盟的保护科学家们在本周于《美国基因协会遗传杂志》上面，详细地介绍了这一事件。

The scientists explained that during a routine analysis of biological samples from the two condors in the San Diego Zoo Wildlife Alliance’s managed breeding program, they confirmed that each condor chick was genetically related to the respective female condor that laid the egg from which it hatched.

这些科学家们解释说，在圣地亚哥动物园野生动物联盟管理的繁殖计划中，对两只秃鹰的生物样本进行常规分析时，他们确认每只秃鹰雏鸟都与下蛋的雌性秃鹰有基因上的关联。
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Neither bird was found to be genetically related to a male condor – and researchers tested 467 male condors in the breeding pool as potential fathers – even though the two mother condors, or dams, had been continuously housed with fertile male partners.

研究人员在繁殖池中测试了467只可能是父亲的雄性秃鹰发现，这两只秃鹰雏鸟都没有与雄性秃鹰有遗传关系 —— 尽管这两只母秃鹰一直在与有生育能力的雄性秃鹰住在一起。

The find, the San Diego Zoo Wildlife Alliance said, was the first in any avian species where the female bird had access to a mate.

圣地亚哥动物园野生动物联盟说，这个发现是所有鸟类中第一次发现雌鸟可以配偶的。

This is truly an amazing discovery," Oliver Ryder, the study's co-author director of conservation genetics at San Diego Zoo Wildlife Alliance, said in a statement. "We were not exactly looking for evidence of parthenogenesis, it just hit us in the face. We only confirmed it because of the normal genetic studies we do to prove parentage. Our results showed that both eggs possessed the expected male ZZ sex chromosomes, but all markers were only inherited from their dams, verifying our findings."

“这真是一个惊人的发现，”该研究的合著者、圣地亚哥动物园野生动物联盟保护遗传学主任Oliver Ryder（奥利弗·赖德）在一份声明中说。“我们并不是在寻找单性生殖的证据，它只是打了我们一个耳光。我们之所以确认这一点，是因为我们做了正常的遗传学研究来证明亲子关系。我们的结果表明，这两个卵子都拥有预期的雄性ZZ性染色体，但所有的标记都是从它们的母亲身上遗传的，证实了我们的发现。”
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In addition to the California condor parthenotes, both dams had also produced numerous offspring via sexual reproduction with their mates. One had 11 chicks and another who was paired with a male for more than 20 years had 23 chicks and reproduced twice more following the parthenogenesis.

除了加州秃鹰单性生殖之外，这两个雌性秃鹰还通过与配偶的有性繁殖生育了大量的后代。其中一只繁育了11只雏鸟，另一只与一只雄性秃鹰配对超过20年的雌性秃鹰生意了23只雏鸟，在单性生殖后又生育了两次。

Parthenogenesis – also known as a "virgin birth" – is a natural form of asexual reproduction in which an embryo that is not fertilized by sperm continues to develop, containing solely the genetic materials of the mother. The offspring are called parthenotes.

单性生殖 —— 也被称为“处女生殖”—— 是一种自然的无性生殖形式，在这种形式中，未经精子受精的胚胎继续发育，只包含母亲的遗传物质。这些后代被称为单性生殖。
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The process is relatively rare in birds and instances were confined mainly to domestic birds and normally observed in females who have no access to males.

这个过程在鸟类中相对罕见，主要在于家养鸟类，通常在无法接触雄性的雌性鸟类中观察到。

California condors are a critically endangered species and the San Diego Zoo Wildlife Alliance said it was through the California Condor Recovery Program and genetics and genomics research that scientists were able to "cross-reference historical genetic records before confirming the outcome of this distinctive case of parthenogenesis."

圣地亚哥动物园野生动物联盟表示，加州秃鹰是一种极度濒危物种，正是通过加州秃鹰恢复计划和遗传和基因组学研究，科学家们交叉参考历史基因记录之后才能够“确认这一独特的单性生殖案例。”

Although one chick died in 2003 at the age of 2 and the other in 2017 at the age of 7, the researchers said they would continue future genotyping efforts in the hopes of identifying other parthenogenetic cases.

尽管一只加州秃鹰雏鸟在2003年2岁时死亡，另一只在2017年7岁时死亡，但研究人员表示，他们将继续未来的基因分型工作，以期发现其他单性生殖的案例。

"These findings now raise questions about whether this might occur undetected in other species," Ryder said.

莱德说：“这些发现现在产生了这样一个问题：这种情况是否会在其他物种中产生，却未被发现。”

Breeding efforts to save California condors have produced more than 1,000 chicks and, following the reintroduction of some to the wild, the population has increased to more than 500 both in human care and free-flying in California, Arizona, Utah and Baja California.

为拯救加州秃鹰而进行的繁育努力工作已经培育出超过1000多只雏鸟，在将一些雏鸟放归野外后，加州、亚利桑那州、犹他州和下加利福尼亚州通过人类保护和自由飞行，秃鹰的数量已经增加了500多只。