Lab results have revealed the answer to what caused a female lion to sprout a mane at Oklahoma City Zoo in the U.S.
The 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 hormone that can contribute to developing male features.
Veterinarians compared Bridget’s blood to samples from her sister, who has no mane. Bridget’s blood also contained a higher level of cortisol, which regulates metabolism and the immune system.
The zoo says the results likely mean the 18-year-old lioness has a benign tumour that’s producing the hormones, but that her health is excellent.
The zoo says female lions with manes are not unheard of, but they are rare.