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)