Despite what certain Southern American politicians might believe (or want us to believe), gender boundaries aren’t so well-defined in the natural world. There are scores of animals that display what’s known as sequential hermaphroditism, in which organisms change genders in response to environmental stimuli or changes in populations. While these types of changes are completely physiological, it’s not completely unheard of for animals to alter their behaviors or appearance to display characteristics of the opposite sex. Now, new research conducted in African game lands is showing that gender fluidity in the animal kingdom might be more common than we think.
Five wild lionesses roaming throughout the Moremi Game Reserve in Botswana’s Okavango delta have been found to grow manes and display aggressive roaring behaviors usually only seen in male lions. Manes are typically only found on male lions, who use them to attract females. Roaring behaviors are likewise usually used only by male lions to mark territory or attract the female and young members of their pride.
The discovery was made by a team of zoologists from the University of Sussex, who have published their research in the African Journal of Ecology. According to lead author Geoffrey D. Gilfillan, a lioness the researchers named SaF05 displays male behaviors which are unusual for lionesses:
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. 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.
SaF05 was observed to kill two lion cubs from a competing pride, a behavior usually only seen in males. She even scent-marks frequently, a territorial behavior normally observed in male lions.
Observations of these lioness’ mating patterns has revealed much lower success in fertility than other lionesses; this could be a sign that there is an unknown genetic trigger for the overproduction of testosterone in this particular lion community. More research and genomic testing might be able to determine the exact cause for these peculiar behaviors, but for now, these masculine lionesses remain a mystery.