Time and again, the religious right use the words “natural” and “unnatural” to support their views on homosexuality, marriage, birth control, adoption, and a host of other sensitive issues. Every single time I see it used, I can think of at least one animal which habitually behaves in the way whichever specific group this time considers “unnatural”. People making these claims clearly have no idea at all about what actually goes on in nature. I’ve got a 500 page textbook on animal homosexuality, if you need a really quick idea of how common it is.
Male-male and female-female pairings have been commonly observed in species very closely related to us, especially “Old World” monkeys, including macaques, baboons, mandrills, and talapoins. Baboons are notably promiscuous (a very value-laden human word), engaging in sexual activity for a variety of social purposes. Partners may be of either gender, and sometimes these encounters are not limited to two individuals.
A pair of male penguins in a zoo in New York formed a long-term, exclusive relationship. When given an egg, they cared for it lovingly until it hatched. The chick, a female, grew up to enter into her own exclusive homosexual relationship.
When a male lion takes over a pride, he may find females caring for cubs sired by the previous dominant male. Like in humans, egg production usually ceases in lions for the duration of rearing offspring. An incoming or arising dominant male often kills the existing cubs in order to force the lionesses into heat so that he can produce his own offspring with them.
The dunnock, a small brown bird, sometimes enters into what looks like a monogamous relationship. However closer observation reveals that a great many of these birds are often in polyandrous (one female, multiple males) and polygynous (one male, multiple females) relationships. The precise configuration of relationships depends very greatly on the control of territory and the availability of resources.
Smaller individuals among giant cuttlefish (yes, small giants) disguise themselves as females. This allows them to get closer to actual females to mate with them without being challenged by larger males. However sometimes the larger males mistake the smaller ones for females, and attempt to mate with them.
Females of many insect and arachnid species will often mate with multiple males for a variety of reasons. In times of poor food availability, the male may be cannibalised after mating to provide the female with important nutrients. This is common in praying mantids. In many species the male will provide a “nuptial gift” to convince the female to mate with him even if she has already mated with a previous male; in human terms he is essentially paying for sex.
I could potentially come up with many many more examples of “immoral” behaviour among animals. I didn’t even tell you about the necrophiliac homosexual mallard. This, this is nature. This is natural. So the next time you want to tell somebody that they can’t do something because it’s “unnatural”, you might want to re-think your argument.