In the news recently, Filipino boxing star, Manny Pacquiao, spoke of homosexuality as being a sin and against the Bible. He also added that animals did not display such behavior: "It’s just common sense. Have you seen any animal having male-to-male or female-to-female relations? Animals are better, they know how to distinguish male from female. If we approve male-on-male, female-on-female, then man is worse than animals." So, putting aside one's religious views and any underlying animus that may be related to this topic and/or what Manny Pacquiao implied with this words, I'm wondering if homosexuality in the animal world is an abnormality" of sorts? For example, I have heard that it's very rare and occurs (unsure if this is exclusive or not) in conditions where there is a lack of opposite-sex mates. Presumably, in situations where opposite-sex mates are plentiful, this behavior doesn't exist. Is this right? 1.) How common is homosexuality in animals? 2.) What are the conditions under which homosexuality takes place in the animal kingdom? 3.) Would the best way to describe it be to say that it's an abnormality of some kind or perhaps an environment-driven behavior? Please note that I am not in any way making any moral judgments of things related to this topic, but merely wanting to understand what the science says about it. Thanks very much and I hope we can have an educational discussion!