These cute and furry creatures seem to develop this tendency for same-sex love when held in captivity. In the wild, koalas are generally heterosexual.

"Some females rejected the advances of males that were in their enclosures, only to become willing participants in homosexual encounters immediately after," according to a study by researchers from the University of Queensland.

What seems to be baffling researchers is that there is no obvious mechanism to explain why the females are changing their behaviour -- and why male koalas remain resolutely straight.

"Wild koalas brought into captivity clearly display homosexual behaviour on a regular basis. A total of 15 heterosexual and 43 homosexual interactions were recorded in separate animals. Homosexual behaviour was restricted to females only."

One theory posited by researchers for the behavioural change is that the koalas are attempting to relive stress.

Another theory is that the females are attempting to attract males with a display of lesbianism. Just like certain human females perhaps.