One must be very careful when making parallels between the behavior of human beings and that of other animals, since it is very easy to engage in the fallacy of anthropomorphism. Attributing to animals the capacity of perceiving the world in the same ways we do, or of having feelings or emotions similar to ours, is a big mistake. Nevertheless, many people fall into the anthropomorphism trap. It is not rare, for example, to hear animal rights activists comparing the “suffering” experienced by cattle in the imminence of slaughter to the anguish that a death- penalty convict faces shortly before execution. Now, a cow is most likely not aware of its own existence, neither is it tormented by metaphysical questions, to mention just a few obvious fundamental differences that undoubtedly make the human suffering under such circumstances incomparably more intense.
Various forms of same-sex sexual activities have been observed in more than 450 animal species. Although this does not necessarily mean that there is such a thing as gay animals (beware the anthropomorphism!), it raises many interesting questions. This link gives access to an excellent New York Times Magazine article named “Can Animals be Gay?” In addition to the interesting scientific information, the article shows how unwise it can be to make moral judgements about nature as well as the dangers of anthropomorphism.