The bonobo, also historically called the pygmy chimpanzee, is an endangered great ape and one of the two species making up the genus Pan. While bonobos are, today, recognized as a distinct species in their own right, they were initially thought to be a subspecies of Pan troglodytes, because of the physical similarities between the two species. Taxonomically, members of the chimpanzee/bonobo subtribe Panina—composed entirely by the genus Pan—are collectively termed panins.
The relationship between biology and sexual orientation is a subject of on-going research. While scientists do not know the exact cause of sexual orientation, they theorize that it is caused by a complex interplay of genetic, hormonal, and environmental influences. However, evidence is weak for hypotheses that the post-natal social environment impacts sexual orientation, especially for males.
Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecious species, which consist of most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male-male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is monomorphism, when both biological sexes are phenotypically indistinguishable from each other.
Dactyloidae are a family of lizards commonly known as anoles and native to warmer parts of the Americas, ranging from southeastern United States to Paraguay. Instead of treating it as a family, some authorities prefer to treat it as a subfamily, Dactyloinae, of the family Iguanidae. In the past they were included in the family Polychrotidae together with Polychrus, but the latter genus is not closely related to the true anoles.
Anolis carolinensis or green anole is a tree-dwelling species of anole lizard native to the southeastern United States and introduced to islands in the Pacific and Caribbean. A small to medium-sized lizard, the green anole is a trunk-crown ecomorph and can change its color to several shades from brown to green.
Various non-human animal species exhibit behavior that can be interpreted as homosexual or bisexual, often referred to as same-sex sexual behavior (SSSB) by scientists. This may include same-sex sexual activity, courtship, affection, pair bonding, and parenting among same-sex animal pairs. Various forms of this are found among a variety of vertebrate and arthropod taxonomic classes. The sexual behavior of non-human animals takes many different forms, even within the same species, though homosexual behavior is best known from social species.
Frot or frotting is a sexual practice between men that usually involves direct penis-to-penis contact. The term was popularized by gay male activists who disparaged the practice of anal sex, but has since evolved to encompass a variety of preferences for the act, which may or may not imply particular attitudes towards other sexual activities. This can also be used as some type of foreplay.
A gynandromorph is an organism that contains both male and female characteristics. The term comes from the Greek γυνή (gynē) 'female', ἀνήρ (anēr) 'male', and μορφή (morphē) 'form', and is used mainly in the field of entomology. Gynandromorphism is most frequently recognized in organisms that have strong sexual dimorphism such as certain butterflies, spiders, and birds, but has been recognized in numerous other types of organisms.
A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck of many vertebrates. More loosely, it can be various similar structures in the neck area, such as those caused by a double chin or the submandibular vocal sac of a frog. More generally, it can be any hanging mass of skin, such as a fold of loose skin on an elderly person's neck, or the wattle of a bird. Dewlaps can be considered as a caruncle, defined as "a small, fleshy excrescence that is a normal part of an animal's anatomy".
Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, polygyny, polyandry, polygamy and promiscuity. Other sexual behaviour may be reproductively motivated or non-reproductively motivated.
The pelvic thrust is the thrusting motion of the pelvic region, which is used for a variety of activities, such as dance, exercise, or sexual activity.
The desert grassland whiptail lizard is an all-female species of reptiles in North America. It was formerly placed in the genus Cnemidophorus. A common predator of the whiptail lizard is the leopard lizard that preys on A. uniparens by using ambush and stalk hunting tactics. These reptiles reproduce by parthenogenesis. In this process, eggs undergo a chromosome doubling after meiosis, developing into lizards without being fertilized. However, ovulation is enhanced by female-female courtship and mating (pseudo-copulation) rituals that resemble the behavior of closely related species that reproduce sexually.
In behavioral science, androphilia and gynephilia are sexual orientations: Androphilia is sexual attraction to men and/or masculinity; gynephilia is sexual attraction to women and/or femininity. Ambiphilia describes the combination of both androphilia and gynephilia in a given individual, or bisexuality. The terms offer an alternative to a gender binary homosexual and heterosexual conceptualization of sexuality.
The Guianan cock-of-the-rock is a species of cotinga, a passerine bird from South America. It is about 30 cm (12 in) in length and weighs about 200 to 220 g. It is found in tropical rainforests, near its preferred habitat of rocky outcrops. The female's plumage is brownish/dark smokey grey in colour, and generally less noticeable than the males because of their nesting work in rocky areas. The male's feathers are a bright orange. Both have a heavy body, broad-based bill and wear a remarkable half-moon crest on the head. It is one of two species of the genus Rupicola, the other being the Andean cock-of-the-rock. The Guianan cock-of-the-rock lives across the forested region of northeastern South America. Its diet consists mostly of fruit, but they sometimes feast on small snakes and lizards.
Penis fencing is a mating behavior engaged in by many species of flatworm, such as Pseudobiceros hancockanus. Species which engage in the practice are hermaphroditic; each individual has both egg-producing ovaries and sperm-producing testes.
Bruce Bagemihl is a Canadian biologist, linguist, and author of the book Biological Exuberance: Animal Homosexuality and Natural Diversity.
Animal non-reproductive sexual behavior encompasses sexual activities that non-human animals participate in which do not lead to the reproduction of the species. Although procreation continues to be the primary explanation for sexual behavior in animals, recent observations on animal behavior have given alternative reasons for the engagement in sexual activities by animals. Animals have been observed to engage in sex for social interaction bonding, exchange for significant materials, affection, mentorship pairings, sexual enjoyment, or as demonstration of social rank. Observed non-procreative sexual activities include non-copulatory mounting, oral sex, genital stimulation, anal stimulation, interspecies mating, same-sex sexual interaction, and acts of affection, although it is doubted that they have done this since the beginning of their existence. There have also been observations of sex with cub participants, as well as sex with dead animals.
Homosexual behavior in sheep has been well documented and studied. The domestic sheep is the only species of mammal except for humans which exhibits exclusive homosexual behavior. "About 10% of rams (males) refuse to mate with ewes (females) but do readily mate with other rams." Thirty percent of all rams demonstrate at least some homosexual behavior. One report on sheep found that 8% of rams exhibited homosexual preferences—that is, even when given a choice, they chose male over female partners. This documented homosexual preference has garnered much discussion. Such rams prefer to court and mount other rams only, even in the presence of estrous ewes. Moreover, around 18–22% of rams are bisexual.
