Same-sex behaviour among female gorillas has been documented for the first time and the Australian behind the study, Associate Professor Dr Cyril Grueter, a primate expert from the University of Western Australia, believes it is motivated by sexual arousal.
He stumbled on the behaviour when studying the feeding ecology of mountain gorillas in Rwanda. Grueter turned his attention to studying what was behind the behaviour.
The study found female gorilla sexuality was very flexible, which is consistent with research that has found human women are more fluid in their sexuality than men, he said. "The female gorillas are quite flexible when it comes to sexuality, they can easily switch from a preference for males to a preference for females," Dr Grueter said.
He added that: "When the male is not available they try to entice another female to mate with them. Out of 22 female gorillas across two separate groups studied, 18 were found to engage in sexual activity with other females, including engaging in genital rubbing. We believe it is simply a function of sexual arousal."