Homosexuality has been documented in more than 450 species of vertebrates signaling that sexual preference is biologically determined in animals. From Male bonobos that hang from trees and engage in "penis fencing" to bull manatees and bottlenose dolphins, the animal kingdom tolerates all kinds of lifestyles.
Homosexuality has been documented in almost 500 species of animals, signaling that sexual preference is predetermined. Considered the closest living relative to humans, bonobos are not shy about seeking sexual pleasure. Nearly all of these peace-loving apes are bisexual and often resolve conflict by the "make love, not war" principle. They copulate frequently, scream out in delight while doing so, and often engage in homosexual activities. About two thirds of the homosexual activities are amongst females.
Female macaques form intense bonds with each other and are serially monogamous, meaning they only have one sexual partner at a time. However, they have several of these relationships during each breeding season. Female macaques engage in sexual activities such as genital stimulation and vocalize their delight in forms of cackling sounds. Males also take to homosexual play but tend to leave their partner soon after, making it what we call in the human world a one night stand.
Male courtships are frequent amongst these long-necked mammals. Often a male will start necking with another before proceeding to mount him. This affectionate play can take up to an hour. According to one study, one in every 20 male giraffes will be found necking with another male at any instant. In many cases, homosexual activity is said to be more common than heterosexual.
Homosexual activity occurs with about the same frequency as heterosexual play amongst these marine mammals. Male bottlenose dolphins are generally bisexual, but they go through periods of being exclusively homosexual. The homosexual activities of these mammals include oral sex during which time one dolphin stimulates the other with its snout. Males also rub their erect penises against the body of their partner. [<a href="http://www.livescience.com/15927-dolphin-species-photos.html">See more pictures of dolphins</a>]
Homosexual mounting between males tends to be more common than heterosexual female-male copulation among American bison, especially because females only mate with the bulls about once a year. During mating season, males engage in same-sex activities several times a day. More than 55 percent of mounting in young males is with the same gender.
On average, females mount with other females a couple of times an hour during the mating season. Homosexual mounting encompasses almost 9 percent of all sexual activities within these hoofed mammals in the wild. While courting, the pursuer sidles up behind a pal and raises her foreleg, touching the other female between her legs. This leggy foreplay ultimately leads to mounting.
Homosexual couples account for up to 20 percent of all pairings annually. Almost a quarter of all families are parented by homosexual couples that remain together for years. At times, male couples use the services of a female by mating with her. Once she lays a clutch of eggs, the wanna-be fathers chase her away and hatch the eggs. Other times, they just drive away heterosexual couples from their nests and adopt their eggs.
Male walruses don't reach sexual maturity until they are four years old. During that time, they are most likely exclusively involved in same-sex relationships. The older males are typically bi-sexual, mating with females during breeding season and copulating with other males the rest of the year. Males rub their bodies together, embrace each other and even sleep together in water. [<a href="http://www.livescience.com/15664-walrus-photos-arctic-sea.html">See more pictures of walruses</a>]
Splashing around in the water is brought to a completely new level in gray whales, where homosexual interactions are quite common. In slip-and-slide orgies, as many as five males roll around, splashing water, and rubbing their bellies against each other so that their genitals are touching.
Males of this stunning perching bird delight in homosexuality. Almost 40 percent of the male population engages in a form of homosexual activity and a small percentage don't ever copulate with females.