Homosexuality in the animal kingdom

A few things I found through Karin Hakalax' blog (thank you!):

I mentioned the biologist Bruce Bagemihl a couple of years ago in the blog post Gayness is natural, in connection with an exhibition, "Against Nature?", at the Museum of Natural History in Oslo, Norway. Here he is again, spreading the news that homosexuality is documented in over 400 species, but probably occurs in 15-30% of the known million of species (which, of course, is not the same as saying that 15-30% of all animals are gay - but interesting, nonetheless).
The video is 8'20" long.

Bagemihl writes:

Male Bottlenose Dolphins often form lifelong pair-bonds with each other. Adolescent and younger males typically live in all-male groups in which homosexual activity is common; within these groups, a male begins to develop a strong bond with a particular partner (usually of the same age) with whom he will spend the rest of his life. The two Dolphins become constant companions, often traveling widely; although sexual activity probably declines as they get older, it may continue to be a regular feature of such partnerships.

The video is 3'08", but technically of poor quality.

And yet another video (4'59") that documents homosexual behaviour among animals:

An article in National Geographic, Homosexual Activity Among Animals Stirs Debate from 2004, deals with the same issue.

The bonobo, an African ape closely related to humans, has an even bigger sexual appetite. Studies suggest 75 percent of bonobo sex is nonreproductive and that nearly all bonobos are bisexual. Frans de Waal, author of Bonobo: The Forgotten Ape, calls the species a "make love, not war" primate. He believes bonobos use sex to resolve conflicts between individuals.
Other animals appear to go through a homosexual phase before they become fully mature. For instance, male dolphin calves often form temporary sexual partnerships, which scientists believe help to establish lifelong bonds. Such sexual behavior has been documented only relatively recently. Zoologists have been accused of skirting round the subject for fear of stepping into a political minefield.
"There was a lot of hiding of what was going on, I think, because people were maybe afraid that they would get into trouble by talking about it," notes de Waal. Whether it's a good idea or not, it's hard not make comparisons between humans and other animals, especially primates. The fact that homosexuality does, after all, exist in the natural world is bound to be used against people who insist such behavior is unnatural.

But to remain honest, I have to include the following passage, as well:

Yet scientists say we should be wary of referring to animals when considering what's acceptable in human society. For instance, infanticide, as practiced by lions and many other animals, isn't something people, gay or straight, generally approve of in humans.

Conclusion: The argument that homosexuality is unnatural, since it doesn't occure in nature, falls flat on its face. This, however, does not automatically mean that what is natural is also good. The "natural-unnatural" -argument is simply moot.