A sex change in the savanna? Five rare lionesses spotted in Botswana have MANES and behave like males

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With their bushy manes and a powerful roar to match, the masculine behaviour observed in a group of lions in Botswana might not seem out of the ordinary – except, they’re female.

Researchers have observed five lionesses at the Moremi Game Reserve in the Okavango delta that act like males, scent-marking at a similar frequency, and even mounting other females.

It’s not known for sure why these lionesses look and behave in this way, but researchers say it’s likely the result of high levels of testosterone, suggesting they may also be infertile.

While sporadic reports of maned lionesses have been recorded in the past, researchers have now observed the existence of five such animals, New Scientist reports.

The unusual behaviour is described in a paper published to the African Journal of Ecology.

Unlike typical females, who lack a mane and do not roar as frequently as males, the lionesses seen at the Moremi Game Reserve exhibit a number of these masculine characteristics.

One was even observed killing two cubs from a neighbouring pride, a behaviour commonly seen in males.

A photo, shared on Twitter by conservation ecologist Simon Dures, reveals a stunning glimpse at one of these rare maned lionesses, walking side-by-side with a much larger male. 

Sporadic reports of maned lionesses have been recorded in the past, researchers say. A maned lioness 'Rose' (on right) can be seen walking with a male at Warsaw's zoo in 2011

Researchers in Botswana, including Geoffrey D. Gilfillan of the University of Sussex in Falmer, first began studying the group in 2014.

Over the next two years, Gilfillan tracked the behaviour of a particular lioness, called SaF05.

According to the researcher, this particular lioness is larger than most females, and has small mane.

‘While SaF05 is mostly female in her behaviour – staying with the pride, mating males – she also has some male behaviours, such as increased scent-marking and roaring, as well as mounting other females,’ Gilfillan told New Scientist.

Unlike typical females, who lack a mane and do not roar as frequently as males, the lionesses seen at the Moremi Game Reserve exhibit a number of these masculine characteristics. A normal lioness is pictured

Researchers say high amounts of testosterone could be to blame for this phenomenon.

It’s known that the hormone is directly tied to the development of the mane – in the case that a male is castrated, he will lose his mane.

And, a female lion held at the National Zoological Gardens of South Africa was found to develop a mane after problems in her ovaries resulted in an increase in testosterone.

Once the issue had been resolved, the mane disappeared.  

The maned lionesses in Botswana appear to be healthy, but none so far have become pregnant, further supporting the theory that increased amounts of androgens, like testosterone, may be the underlying cause, New Scientist reports.

And as they all originate from the same region, researchers speculate genetics may play a role.