List of mammals displaying homosexual behavior

This is a list of mammals for which there is documented evidence of homosexual behavior. These animals have been observed practicing homosexual courtship, sexual behavior, affection, pair bonding, or parenting.

Bruce Bagemihl writes that the presence of same-sex sexual behavior was not officially observed on a large scale until the 1990s due to possible observer bias caused by social attitudes towards LGBT people, which made homosexuality in animals a taboo subject. He devotes three chapters, "Two Hundred Years at Looking at Homosexual Wildlife", "Explaining (Away) Animal Homosexuality", and "Not For Breeding Only" in his 1999 book Biological Exuberance to the "documentation of systematic prejudices" where he notes "the present ignorance of biology lies precisely in its single-minded attempt to find reproductive (or other) "explanations" for homosexuality, transgender, and non-procreative and alternative heterosexualities. Petter Bøckman, academic adviser for the Against Nature? exhibit, stated "[M]any researchers have described homosexuality as something altogether different from sex. They must realise that animals can have sex with who they will, when they will and without consideration to a researcher's ethical principles". Homosexual behavior is found amongst social birds and mammals, particularly the sea mammals and the primates.

Animal sexual behavior takes many different forms, even within the same species and the motivations for and implications of their behaviors have yet to be fully understood. Bagemihl's research shows that homosexual behavior, not necessarily sexual activity, has been documented in about 500 species as of 1999, ranging from primates to gut worms. Homosexuality in animals is controversial with some social conservatives because it asserts the naturalness of homosexuality in humans, while others counter that it has no implications and is nonsensical to equate animal behavior to morality. Animal preference and motivation is inferred from behavior, thus homosexual behavior has been given a number of terms over the years. Modern research   applies the term homosexuality to all sexual behavior (copulation, genital stimulation, mating games and sexual display behavior) between animals of the same sex.

This is a list of some mammals that have been recorded engaging in homosexual behavior, which is part of a larger list of animals displaying homosexual behavior including birds, insects, fish, etc.

List

 * American bison
 * Antelope
 * Asian elephant
 * Asiatic mouflon
 * Atlantic spotted dolphin
 * Australian sea lion
 * Barasingha
 * Barbary sheep
 * Beluga
 * Bharal
 * Bighorn sheep
 * Black bear
 * Blackbuck
 * Black-footed rock wallaby
 * Black-tailed deer
 * Bonin flying fox
 * Bonnet macaque
 * Bonobo
 * Bottlenose dolphin
 * Bowhead whale
 * Brazilian guinea pig
 * Bridled dolphin
 * Brown bear
 * Brown capuchin
 * Brown long-eared bat
 * Brown rat
 * Buffalo
 * Caribou
 * Cat (domestic)
 * Cattle (domestic)
 * Chacma baboon
 * Cheetah
 * Chimpanzee
 * Chital
 * Collared peccary
 * Commerson's dolphin
 * Common brushtail possum
 * Common dolphin
 * Common marmoset
 * Common pipistrelle
 * Common tree shrew
 * Common wallaroo
 * Cotton-top tamarin
 * Crab-eating macaque
 * Crested black macaque
 * Dall's sheep
 * Daubenton's bat
 * Dog (domestic)
 * Donkey
 * Doria's tree kangaroo
 * Dugong
 * Dwarf cavy
 * Dwarf mongoose
 * Eastern cottontail rabbit
 * Eastern grey kangaroo
 * Elk
 * European bison
 * European polecat
 * Fallow deer
 * False killer whale
 * Fat-tailed dunnart
 * Fin whale
 * Fox
 * François' langur
 * Gazelle
 * Gelada baboon
 * Goat (domestic)
 * Golden monkey
 * Giraffe
 * Gorilla
 * Grant's gazelle
 * Grey-headed flying fox
 * Grey seal
 * Grey squirrel
 * Grey whale
 * Grey wolf
 * Grizzly bear
 * Guinea pig (domestic)
 * Hamadryas baboon
 * Hamster (domestic)
 * Hanuman langur
 * Harbor porpoise
 * Harbor seal
 * Himalayan tahr
 * Hoary marmot
 * Horse (domestic)
 * Human (see Human sexual behavior)
 * Humpback whale
 * Indian fruit bat
 * Indian muntjac
 * Indian rhinoceros
 * Japanese macaque
 * Javelina
 * Kangaroo rat
 * Killer whale
 * Koala
 * Kob
 * Larga seal
 * Least chipmunk
 * Lechwe
 * Lesser bushbaby
 * Lion
 * Lion-tailed macaque
 * Lion tamarin
 * Little brown bat
 * Livingstone's fruit bat
 * Long-eared hedgehog
 * Long-footed tree shrew
 * Macaque
 * Markhor
 * Marten
 * Masked palm civet
 * Moco
 * Mohol galago
 * Moor macaque
 * Moose
 * Mountain goat
 * Mountain tree shrew
 * Mountain zebra
 * Mouse (domestic)
 * Moustached tamarin
 * Mule deer
 * Musk-ox
 * Natterer's bat
 * New Zealand sea lion
 * Nilgiri langur
 * Noctule
 * North American porcupine
 * Northern elephant seal
 * Northern fur seal
 * Northern quoll
 * Olympic marmot
 * Orangutan
 * Pacific striped dolphin
 * Patas monkey
 * Pere David's deer
 * Pig (domestic)
 * Pig-tailed macaque
 * Plains zebra
 * Polar bear
 * Pretty-faced wallaby
 * Proboscis monkey
 * Pronghorn
 * Przewalski's horse
 * Pudú
 * Puku
 * Quokka
 * Rabbit
 * Raccoon
 * Raccoon dog
 * Red deer
 * Red fox
 * Red kangaroo
 * Red-necked wallaby
 * Red squirrel
 * Reeves's muntjac
 * Reindeer
 * Rhesus macaque
 * Right whale
 * Rock cavy
 * Rodrigues fruit bat
 * Roe deer
 * Rufous bettong
 * Rufous-naped tamarin
 * Rufous rat kangaroo
 * Saddle-back tamarin
 * Savanna baboon
 * Sea otter
 * Serotine bat
 * Sheep (domestic)
 * Siamang
 * Sika deer
 * Slender tree shrew
 * Snub-nosed monkey
 * Sooty mangabey
 * Sperm whale
 * Spider monkey
 * Spinifex hopping mouse
 * Spinner dolphin
 * Spotted hyena
 * Spotted seal
 * Squirrel monkey
 * Striped dolphin
 * Stuart's marsupial mouse
 * Stumptail macaque
 * Swamp deer
 * Swamp wallaby
 * Takhi
 * Talapoin
 * Tammar wallaby
 * Tasmanian devil
 * Tibetan macaque
 * Tasmanian rat kangaroo
 * Thinhorn sheep
 * Thomson's gazelle
 * Tiger
 * Tonkean macaque
 * Tucuxi
 * Urial
 * Ursine colobus
 * Vampire bat
 * Verreaux's sifaka
 * Vervet
 * Vicuna
 * Walrus
 * Wapiti
 * Warthog
 * Waterbuck
 * Water buffalo
 * Weeper capuchin
 * Western grey kangaroo
 * West Indian manatee
 * Whiptail wallaby
 * White-faced capuchin
 * White-fronted capuchin
 * White-handed gibbon
 * White-lipped peccary
 * White-tailed deer
 * Wild cavy
 * Wild goat
 * Yellow-bellied marmot
 * Yellow-footed rock wallaby
 * Yellow-toothed cavy