Many of the earliest artifacts of human culture (such as cave drawings
and sculptures) indicate that humans have been preoccupied with sex for
as about as long as there have been humans. For thousands of years, human
cultures have also been concerned with identifying what each culture felt
were appropriate expressions of sexuality and which expressions were inappropriate.
Often, the justification for the appropriateness of sexual acts centered
on whether or not it was "natural". As our understanding of
animal sexuality has increased, the variations of sexual behavior which
occur in nature (and thus are "natural" in the original sense
of the word) has grown.
Open mouth kissing (including same sex kissing) occurs in Bonobo chimps,
common chimps, and squirrel monkeys. Open mouth kissing can be intense
in Bonobos (Bagemihl, 1999; Fouts, 1997).
Apes have displayed a diverse array of sexual practices, some of which
were previously thought to be unique to humans. These include the "missionary"
position (Orangs and Bonobos; common chimps do rarely while this is the
position of 1/3 of Bonobo matings), a variety of sexual positions (Bonobos);
and sex used for purposes other than procreation (to reconcile, make friends,
and calm tension in Bonobos; in exchange for food in common chimps).
In gibbons, Bonobos, and Old World monkeys, sexual activity can occur
when females are not able to conceive. Bonobo females are continually
sexually receptive (Savage-Rumbaugh, 1998). Face to face intercourse occurs
in gorillas, Bonobos, gibbons, and dolphins. Anal stimulation frequently
occurs in heterosexual encounters between orangutans Bagemihl, 1999).
The former name for chimpanzees was Pan satyrus for their sexual activity.
In a colony with four males, a female may mate six times a day during
estrus (although the mating typically lasts for less than 15 seconds).
Dominant males mate more frequently than males of lower rank. Females
experience climax (De Waal, 1982). Female common chimpanzees may mate
several hundred times per conception. (Bagemihl, 1999). Bonobos engage
in sexual activity more frequently than in common chimpanzees and this
activity plays a factor in female relationships and group cohesiveness
Female gorillas average 7 births per female while chimpanzees average
4 (Wrangham, 1994).
Clitoral rubbing in bonobo chimps, rhesus monkeys, and gorillas. Female
penetration can involve fingers, tails (dolphins), an erect clitoris (Bonobo
chimps), and foreign objects . Mutal masturbation occurs in macaques.
Masturbation is known in in gorillas, rhesus monkeys, macaques, vampire
bats, and proboscis monkeys (Bagemihl, 1999). Lucy (a chimp) would masturbate
with a vacuum cleaner (after plugging it in) and would "read"
National Geographic regularly until estrus at which time she preferred
Playgirl (Fouts, 1997).
Oral sex which involves sucking occurs in Bonobos, orangutans, siamangs,
stumptail macaques; licking more common in animals as diverse as hyenas,
cheetahs, sheep, and vampire bats (Bagemihl, 1999).
Same-sex sexual activity is known in more than 450 kinds of animals including
representatives of every major group of animals and every continent of
the world. Same-sex contact includes lip contact and open-mouth kissing
(Bagemihl, 1999). Male anal intercourse occurs in orangutans, bonobo chimps,
rhesus monkeys, bison, and bighorn sheep. Same sex pairs may raise young,
especially in birds.
Same-sex mounting and genital manipulation has been observed in a number
of species of New World monkeys. Same-sex mounting has been observed in
some prosimians. (Bagemihl, 1999).
All female Hanuman langurs have same-sex relationships (Bagemihl,
1999). Amoung macaques, most females are bisexual while many are heterosexual
and some are exclusively homosexual. In an number of Old World monkeys
and apes, the frequency of homosexual encounters varies from population
to population (Bagemihl, 1999).
Homosexual activity in orangutans includes male anal intercourse,
oral genital contact, kissing, and manual masturbation. Most males probably
bisexual, at least when young and most females are bisexual (Bagemihl,
Gorilla females and males frequently engage in same-sex
affectionate relationships, often with a particular individual of the
group. In both males and females, same-sex interactions last longer than
heterosexual ones and more frequently use face to face interactions as
opposed to mounting from the rear. Most males are bisexual (at least when
young and in all-male groups) and some are exclusively heterosexual or
homosexual. There is variation among females as to whether they are bisexual,
predominantly heterosexual, or predominantly homosexual (Bagemihl, 1999).
About 1/3 of the mounting between common chimps occurs between males.
Manual stimulation and same-sex kissing can also be common in males and
females. In some populations, almost all males may participate in homosexual
activity. Some individuals seem to have a homosexual orientation (Bagemihl,
Bonobo chimps utilize G-G rubbing, orgasm, female group
sex, anal stimulation, oral sex, same sex kissing; 40 to 50% of sexual
activity is homosexual and almost all bonobos are bisexual. (Bagemihl,
Bonobos can have sexual interactions with redtail monkeys in the wild.
Male orangutans may have homosexual encounters with male crab-eating macaques