Non-reproductive sexual behavior in animals
Observed non-procreative sexual activities include non-copulatory mounting (without insertion, or by a female, or by a younger male who does not yet produce semen), oral sex, genital stimulation, anal stimulation, interspecies mating, same-sex sexual interaction,[2][3] and acts of affection, although it is doubted that they have done this since the beginning of their existence.
In fact, young females go through a five-to-six-year period sometimes referred to as adolescent sterility (although no pathology is involved) during which they actively participate in heterosexual mating (often with adults) but never get pregnant.
Through extensive research, scientists have been able to conclude that the brain reward system in animals is extremely similar to that of humans.
Because animals possess a brain reward system they are motivated to perform in different ways by desire and reinforced by pleasure.
[11] Animals establish security of food, shelter, social contact, and mating because proximate mechanism, if they do not seek these necessities they will not survive.
Neurophysiologists have not found any fundamental difference between the structure and function of neurons and synapse between humans and other animals.
[13] Recent studies using positron emission tomography (PET) and magnetic resonance imaging (MRI) has provided evidence proving that chemical changes that occur with emotions are similar between humans and non-human animals.
[15] Kissing, touching of noses, mouths and muzzles have been witnessed in African elephants, walruses, and mountain zebras.
Chimpanzees have full mouth-to-mouth contact, and bonobos kiss with their mouth open and mutual tongue stimulation.
[2] There are a variety of acts to show affection such as African elephants intertwining their trunks, giraffes engaging in "necking", and Hanuman langurs cuddling with each other in a front to back sitting position.
There are several techniques, in which animals engage in masturbation from using paws, feet, flippers, tails, and sometimes using objects like sticks, pebbles, and leaves.
[16] Anal insertion with the penis (both in heterosexual and male homosexual dyads, i.e. pairs of animals) has been observed among some primate species.
Male homosexual anal insertion has been recorded in Old World primate species, including gorillas, orangutans, and some members of the Macaca genus (namely, stumptail, rhesus, and Japanese macaques).
[38] A review from the University of Pennsylvania School of Veterinary Medicine says:[39] [The] behavior known within the horse breeding industry as masturbation ... involves normal periodic erections and penile movements.
[40] Attempting to inhibit or punish masturbation, for example by tying a brush to the area of the flank underside where the penis rubs into contact with the underside, which is still a common practice of horse managers regionally around the world, often leads to increased masturbation and disturbances of normal breeding behaviour.
[citation needed] Sexologist Havelock Ellis in his 1927 Studies in the Psychology of Sex identified bulls, goats, sheep, camels and elephants as species known to practice autoeroticism, adding of some other species: I am informed by a gentleman who is a recognized authority on goats, that they sometimes take the penis into the mouth and produce actual orgasm, thus practicing autofellatio.
In his 1999 book, Biological Exuberance, Bruce Bagemihl documents that: Autoeroticism also occurs widely among animals, both male and female.
A variety of creative techniques are used, including genital stimulation using the hand or front paw (primates, Lions), foot (Vampire Bats, primates), flipper (Walruses), or tail (Savanna Baboons), sometimes accompanied by stimulation of the nipples (Rhesus Macaques, Bonobos); auto-fellating or licking, sucking and/or nuzzling by a male of his own penis (Chimpanzees, Savanna Bonobos, Vervet Monkeys, Squirrel Monkeys, Thinhorn Sheep, Bharal, Aovdad, Dwarf Cavies); stimulation of the penis by flipping or rubbing it against the belly or in its own sheath (White-tailed and Mule Deer, Zebras and Takhi); spontaneous ejaculations (Mountain Sheep, Warthogs, Spotted Hyenas); and stimulation of the genitals using inanimate objects (found in several primates and cetaceans).
[43] Many birds masturbate by mounting and copulating with tufts of grass, leaves or mounds of earth, and some mammals such as primates and dolphins also rub their genitals against the ground or other surfaces to stimulate themselves.
Autoeroticism in female mammals, as well as heterosexual and homosexual intercourse (especially in primates), often involves direct or indirect stimulation of the clitoris ...
[43]and that: Apes and Monkeys use a variety of objects to masturbate with and even deliberately create implements for sexual stimulation ... often in highly creative ways.
[43] David Linden, professor of neuroscience at Johns Hopkins University, remarks that: ... perhaps the most creative form of animal masturbation is that of the male bottlenose dolphin, which has been observed to wrap a live, wriggling eel around its penis.
Although easily confused by laypeople, autofellatio and oral sex are separate, sexually oriented behaviors, distinct from non-sexual grooming or the investigation of scents.
Autofellatio and oral sex in animals is documented in spiders (Darwin's bark[46] and widow[47]), brown bears,[48] stump-tailed macaques,[49] Tibetan macaques,[50] wolves,[51] goats, primates, bats,[52] cape ground squirrels[29] and sheep (see section Masturbation for details).
Homosexual behaviour does occur in the animal kingdom outside humans, especially in social species, particularly in marine birds and mammals, monkeys, and the great apes.
Engaging in homosexual behavior may allow species to obtain benefits such as gaining practice, relieving tension, and experiencing pleasure.
[2][12][15] Georgetown University professor Janet Mann has specifically theorised that homosexual behaviour, at least in dolphins, is an evolutionary advantage that minimizes intraspecies aggression, especially among males.
Homosexual behaviour is found in 6–10% of rams (sheep) and associated with variations in cerebral mass distribution and chemical activity.
Such rubbing between males is thought, according to varying evolutionary theorists, to have existed before the development of hominids into humans and bonobos, and may or may not have occurred in the homosexual activity of both of these genetically related species.
In contrast, adult gorillas do not show any sexual interest in juvenile or infant members of their species.
