Lab results have revealed the answer to a mystery at an Oklahoma zoo: Just what caused a female lion to sprout¹ a mane.

近日，实验室的一项研究结果揭示了俄克拉荷马州动物园的一个谜题：是什么导致一头雌狮长出了鬃毛。

The Oklahoma City Zoo says in its March newsletter that testing at the University of Tennessee found the African lioness named Bridget has an elevated level of androstenedione, a hormone² that can contribute to developing male features.

俄克拉荷马城动物园在其3月份的时事通讯中称，田纳西大学的测试发现，非洲雌狮布丽姬特的雄烯二酮水平较高，这是一种能促进雄性特征的激素。

Veterinarians compared Bridget's blood to samples from her sister, who has no mane.

兽医将布丽姬特的血液和它没长鬃毛的姐姐的样本进行了比较。

Bridget's blood also contained a higher level of cortisol, which regulates metabolism³ and the immune system.

在布丽姬特的血液中，可以调节新陈代谢和免疫系统的皮质醇的水平也要更高。

The zoo says the results likely mean the 18-year-old lioness has a benign⁴ tumor⁵ that's producing the hormones⁶, but that her health is excellent.

该动物园称，这一结果可能意味着这头18岁的雌狮长了可以产生激素的良性肿瘤，但她的健康状况却很不错。

The zoo says female lions with manes are not unheard of, but they are rare.

园方表示，长鬃毛的雌狮并不是前所未闻的，只是这一情况比较罕见。