Does Homosexuality Exist Within the Animal Kingdom?

Uganda's First Lady Janet Museveni raised eyebrows when she told a gathering of bishops that if cows were not homosexual, humans could not be gay either.

Had she checked her facts first she may have not have used that argument to validate her country's anti-gay stance.

According to research, same-sex sexual activity has been recorded in almost 1,500 species - from beetles, flamingos, bison and yes, cows, too.

Scientists have argued that bovine lesbianism in domesticated cattle is often displayed because the animals are enclosed in stressful conditions. Homosexual behaviour, however, was not apparent in wild cattle.

Sheep, on the other hand, like to have exclusive homosexual relations. Around 10% of rams (males) refuse to mate with ewes (females), and prefer to mate with each other.

But Simon LeVay, a British-American neuroscientist, said homosexual relationships in the animal kingdom was not always exclusive and never lasted long.

He said: "Although homosexual behaviour is very common in the animal world, it seems to be very uncommon that individual animals have a long-lasting predisposition to engage in such behaviour to the exclusion of heterosexual activities. Thus, a homosexual orientation, if one can speak of such thing in animals, seems to be a rarity."

But if you take the example of the female alabatross community at Kaena Point on the island of O'ahu it seems they have no choice but to get together because of a dearth of males. If a female cannot find an otherwise committed male to incubate an egg (because it takes two albatrosses) it will pair with another female.

Female koalas have been known to force each other against trees and mount one another, especially those in zoos, in a phenomenon known as the "prisoner effect". One scientist recalled hearing "exhalated belchlike sounds" when one threw back its head.

Male Amazon River dolphins have also been known to penetrate each other - through the blowhole.

Canadian primatologist and evolutionary psychologist Paul Vasey said heterosexual sex in animals was primarily for reproduction and there was not a straight answer as to why homosexual behaviour was displayed among species.

He said: "Biologists want to build these unified theories to explain everything they see. But none of this lends itself to a linear story. Homosexual behaviour is not a uniform phenomenon. Having one unifying body of theory that explains why it's happening in all these different species might be a chimera."