Homosexual behaviour is extensively found in nature. “It has been observed in: antelopes, boars, bulls, chimpanzees, cows, ducks, cats, dogs, fruit flies, geese, gorillas, gulls, horses, humans, langurs, rams, sheep, macaques, monkeys, turkeys and vervets.” 2
According to research conducted by Bruce Bagemihl, a biologist from Seattle, Washington, at least 5% of Humboldt penguin pairs he observed in a zoo were gay. In his book, he has surveyed homosexual and transgender behaviours among 190 species, such as butterflies and other insects.3
Another source states that “Homosexuality exists in proven ratios in all mammal species….It is as natural as blue eyes, left-handedness, or the genetic predisposition to walk on two legs.” 4
It is interesting to note that the Greek philosopher Aristotle noted apparent homosexual behaviour among hyenas about 2300 years ago.5