Scientist have long know that homosexuality and bisexuality are common in the animal world, but we now have a prime example of how gender presentation isn't necessarily fixed, either.

A lioness in Botswana has been recorded growing a full mane, a characteristic generally associated with males.

The BBC has filmed Mmamoriri, who also roars like a male, on the plains of the Okavango Delta for the documentary the World's Sneakiest Animals. She's one of five lionesses in the area with this adaptation, which is believed to be connected to an increase in male hormones.

As for the evolutionary benefit, presenting as male could help Mmamoriri defend herself and her cubs from invading prides.

"If they can increase their territory because of this then it would really improve her pride’s survival chances," says naturalist Chris Packham. "This mutation could even be the start of a new devious lion strategy."

The animal world is full of creatures that cross the gender divide: Sometimes its a mutation—like male deer who don't grow antlers and are able to stealthily mate with females—and sometimes it's a factory feature, like male seahorses giving birth to their young.

The World’s Sneakiest Animals airs 6:30pm on Christmas day on BBC2.

h/t: Gay Star News