“The National History Museum at the University of Oslo has just opened an exhibition of gay animals. Homosexuality has been recorded in some 1500 species so far, and been well documented in about a third of these cases; it has been known since the time of Aristotle, who thought he witnessed two male hyenas having sex with one another. Aside from illustrating homosexuality among an extraordinary variety of creatures, the exhibition shows how sexual stimulation can vary when, at first blush, the mechanical details of how this might work are not obvious to people attempting to draw analogies from their own anatomy. Male Amazonian river dolphins, for example, penetrate the blowholes of other males; female bottlenose dolphins use their snouts as dildos on other females.Quote from The Economist 2006 Oct 28, added to my text on "Homosexuality is Natural and Occurs in Many Animal Species" that opens my page on homosexuality in general.
Why this behaviour might be favoured by natural selection, though, is a difficult question to answer. In an attempt to do so, the exhibition picks on gay flamingos. Two males raising a chick after one of them had a one-night stand (of sorts) with a female are able to hold a larger territory than male-female partnerships. This suggests a chick with two dads could get more food and therefore have a better chance of survival. [...] One [theory] is that homosexuals assist in the upbringing of their relatives so much that they pass on more of their genes this way than by having children themselves.”
(And, I'm back from Berlin, had a great time!)