Most of us get taught that in the world of lions, the males are the ones with the lustrous mane while the females are more demure in appearance. But one population in the Okavango Delta in Botswana turns this on its head. At least five females living there have been found to be growing manes; not only that, some are also showing male-associated behaviors, such as roaring and mounting other females.
These atypical female lions have been known about for some time now, but the first study formally describing them has been published in the African Journal of Ecology. Out of 34 adult females studied, five of them were found to be sporting a mane more normally associated with males. One of the females, known affectionately as SaF05, went even further, however, and was observed acting in ways more normally associated with the other sex.
“While SaF05 is mostly female in her behavior – staying with the pride, mating males – she also has some male behaviors, such as increased scent-marking and roaring, as well as mounting other females,” co-author Geoffrey Gilfillan of the University of Sussex told New Scientist. “Although females do roar and scent-mark like males, they usually do so less frequently. SaF05, however, was much more male-like in her behavior, regularly scent-marking and roaring.”
The lion on the right here is actually a female known as Mmamoriri
So what is causing these females to develop a male appearance and behavior? The most likely explanation is an abnormal level of testosterone. When male lions are neutered, for example, they lose their mane. It could also help explain the male-associated behaviors, and the fact that SaF05 is notably bigger than the more typical females in her pride. This could go some way to explain a couple of the other oddities observed with these females.
Despite displaying some homosexual behavior, with SaF05 seen mounting other females in the pride, she would also regularly engage in sex with the male of the group. Yet even though she did so on multiple occasions over a period of years, she has yet to produce any cubs. A high level of testosterone is known to cause infertility in female lions. The maned females also tend to be larger and stronger, giving them an advantage when taking down large prey like buffalo and zebra.
The fact that the more masculinized females have all been reported in the same area, with past anecdotal reports suggesting that multiple females from the same pride have also had manes, strongly suggests there is some genetic component to the condition. The isolated nature of the Okavango Delta in which they live, which means limited gene flow between different reserves, could be a factor in why it's so prevalent in this one region.
[H/T: New Scientist]