The behaviour was observed by scientists during a research trip to the Rwandan section of the Virunga mountain range in central Africa.
The wild mountain gorillas, observed by a team led by Dr Cyril Grueter of the University of Western Australia, are believed to gain pleasure from having sex and may do it when they have been rejected by males.
While many species of male primates are well known to engage in homosexual behaviour, females have been subject to far less attention. Female gorillas have also been observed having lesbian sex in Uganda, but the data has not been published or subject to scrutiny.
Source: The Independent