Queer Animals Are Everywhere. Science Is Finally Catching On.

This article by animal studies graduate student Eliot Schrefer for The Washington Post highlights a recent surge in scholarship on same-sex animal behavior which challenges longstanding misconceptions about the connection between animal sexuality and evolution.

All male red-sided garter snakes wear female perfume and participate in same-sex copulation every year. (Gender Showcase, 9-12)

Species: Thamnophis sirtalis parietalis

All male garter snakes wear female perfume and participate in same-sex copulation every year.

In 1985 some male garter snakes were found with female perfumes in their skin. Of two hundred mating balls, about 15 percent consisted of a male, presumably with female perfumes in his skin, surrounded by courting males...In choice experiments [tests where they were given a choice between female and feminine male], the males preferred a female to a feminine male, showing that males could tell the difference—they were not deceived.

In 2000 it was found that all male garter snakes have female perfumes when they emerge from the den in the spring and that all males court these perfumed males in addition to females. 

Four Flawed Deceit-Based Hypotheses:

Investigators floated four deceit-based theories to explain why all males have female perfumes on emergence: (1) a perfumed male may confuse the other males while carrying out its own mating; (2) the perfumed male may avoid wasting energy in courting before he has fully awakened from hibernation; (3) a perfumed male may induce the other males to waste time and energy courting him while he gets ready to start his own courting; and (4) a perfumed male may distract other males from females so he has more to himself when he does get going.

The simplest Occam’s Razor hypothesis:

The female perfumes might protect from attack or mounting when he is emerging, to lessen hostility and improve cooperation.

15 percent of garter snake mating balls consist of a male surrounded by courting males.

These snakes appear to participate in group sex every year as a way to improve relationships and reduce aggression.

Photo credit: Flickr user @vabbley

Originally, scientists dismissed this explanation without even considering it, because they thought the theory required that organisms could only be habitually aggressive and antagonistic. Garter snakes tend to be friendly, especially with 20,000 in one giant group sex mating ball!

Citations

  • R. Mason and D. Crews, 1985, Female mimicry in garter snakes, Nature 316:59-60

  • R. Shine, D. O’Connor, and R. Mason, 2000, Female mimicry in garter snakes: Behavioural tactics of “she-males” and the males that court them, Can. J. Zool. 78-391-96. [Ed. note: Do not use “she-male” to describe transgender people. This is historically used as a harmful pejorative word to demean and exclude.]

  • R. Shine, P. Harlow, M. Lemaster, I. Moore, and R. Mason, 2000, The transvestite serpent: Why do garter snakes court (some) other males? Anim. Behav. 59:349-59. [Ed. note: This sensationalist title should not detract from the data recorded or this paper’s role documenting now-revised theories.]See also http://www.naturenorth.com/spring/creatre/garter/Fgarter.html

  • Roughgarden, J. (2013) Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People. University of California Press, Berkeley. p. 97-8.

80% of gay swan couples successfully raise their young, compared to 30% of straight swan couples. (Gender Showcase, 9-12)

Life-long pair-bonded male-male couples of the species Cygnus atratus will raise an egg together donated by a female.

Male-male black swan parents are more successful.

80% of gay black swan couples successfully raise their young, but only 30% of straight swan couples successfully raise their young.

Black swans (Cygnus atratus) also form stable male-male pairs that last for many years. Gay swans may even raise offspring together as a couple. A female may temporarily associate with a male-male pair, mate with them, and leave her eggs with them.

By sharing the workload more equally, male-male parents access better nesting sites and territories than straight couples.

The male couple then parents the eggs and is reported to be more successful than a male-female couple because together they access better nesting sites and territories, sharing the workload more equally than between-sex couples.

A full 80-percent of the gay couples successfully fledge their young, compared with 30 percent for straight couples. (EN19)

(EN19) L.W. Braithwaite, 1981, Ecological studies of the black swan: III. Behavior and social organization, Australian Wildlife Research 8:135-46.

Citation: Roughgarden, J. (2013) Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People. University of California Press, Berkeley. p. 136.

Update (5/24/23): Thanks to J. Boeheme at Science TV Australia for clarifying these papers are about black swans, not all swans.

All bighorn rams that mate with ewes participate in gay courting & copulation most of the year. (Gender Showcase, 9-12)

Bighorn Sheep

1. Males (rams) & females (ewes) live separately except during breeding season.

2. Females are only sexually active 3 days of the year! They refuse all other approaches the rest of the time.

Book excerpt:

The males (rams), with large thick horns that curl back from above the eye to behind the ear, weigh up to 300 pounds. Their macho appearance has become a symbol for many male athletic teams. The females (ewes) live separately from the males. The sexes associate only during the breeding season, called the rutting season, which extends from mid fall to early winter. A female is receptive for about three days, and will not allow herself to be mounted outside of these three days. (EN29)

(EN29 ) V. Geist (1971) Mountain Sheep: A Study in Behavior and Evolution, University of Chicago Press; J.T. Hogg (1984) Mating in bighorn sheep: Multiple creative male strategies, Science 225: 526-29; J.T. Hogg (1987) Intrasexual competition in and mate choice in rocky mountain bighorn sheep, Ethology 75: 119-44.

All male bighorn sheep that breed with female ewes also participate in homosexual courting & anal copulation.

Book excerpt:

The males have been described as “homosexual societies.” Almost all males participate in homosexual courting and copulation. Male-male courtship begins with a stylized approach, followed by genital licking and nuzzling, and often leads to anal intercourse in which one male, usually the larger, rears up on his hind legs and mounts the other. The mounted male arches his back, a posture known as lordosis, which is identical to how a female arches her back during heterosexual mating. The mounting male has an erect penis, makes anal penetration, and performs pelvic thrusts leading to ejaculation.

Source: Roughgarden, J. (2013) Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People. University of California Press, Berkeley. pp. 137-38.

article excerpt:

Four behavioral phenotypes have been described in domestic rams raised in all-male groups: female-oriented, male-oriented, bisexual, and asexual. To make behavioral assignments, rams are first given sexual performance tests, also known as serving capacity tests, to determine whether or not they are attracted to females and to get a measure of their sexual performance.

Source: Roselli, C. E., Reddy, R. C., & Kaufman, K. R. (2011). The development of male-oriented behavior in rams. Frontiers in neuroendocrinology, 32(2), 164–169. https://doi.org/10.1016/j.yfrne.2010.12.007.

Bighorn Sheep have 3 behavior-based genders & 2 body types:

1. Female-body ewes live separately from gay male rams and only accept mounting 3 days of the year.

2. Male-body rams live together separately from females and copulate anally with other male-body sheep most of the year.

3. Male-body rams that live with female-body ewes most of the year and refuse mounting by other male-body rams.

Book excerpt:

The few males who do not participate in homosexual activity…are identical in appearance to other males but behave quite differently. (EN30) They differ from [so-called] “normal males” by living with the ewes rather than joining all-male groups. These males do not dominate females, are less aggressive overall, and adopt a crouched, female urination posture. These males refuse mounting by other males. In physical appearance, including body size and horn development, these males are indistinguishable from other males.

(EN30) J. Berger. (1985) Instances of female-like behaviour in a male ungulate, Anim. Behav. 33:333-35.

Citation: Roughgarden, J. (2013) Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People. University of California Press, Berkeley. pp. 137-38.

Species: Ovis canadiensis (wiki)

Range: North American (Rocky Mountains, Sierra Nevada, southwestern US, Mexico)