Listen, if you're a Japanese macaque, everyone knows you've got only one thing on your mind: having sex with a deer. Wait, what? Earlier this year, researchers in Minoo, Japan, reported a single instance of a male macaque attempting to mate with a female Sika deer. Though fascinating to scientists who study sexual behavior in animals, the report was largely anecdotal and could have been an isolated incident.
Researchers thought the subject deserved some followup (who wouldn't?), so a team went out to further investigate the phenomena, and what they found shocked them. Though the initial report featured a male macaque having sex with a female Sika deer, the behavior was even more widespread among female macaques and male Sika deer. During their study, the scientists recorded 258 separate instances of female macaque "mounts."
Though scientists have recorded other instances of sex between animals of different species, it is most often non-consensual and seen as an aggressive behavior. In this case, however, researchers recorded "successful heterospecific consortships" between the deer and the female monkeys, suggesting these couples had temporary but exclusive sexual associations. What's more, the report theorized that the deer benefited from, and perhaps even consented to, their relationship with the randy macaques.
During the vast majority of heterospeciﬁc consortships, adult male deer behaved passively, either standing still or slowly foraging while being recipients of the monkeys’ sexual activities. Our preliminary observations suggest that this tolerance on the part of stags may translate into some potential hygienic benefits in the form of allo-grooming by the monkeys. This grooming was specifically directed to body parts that are not easily accessed by the deer.
The report also theorized that adolescent female macaques, who are often rejected by senior males, use the deer to satisfy their sexual frustration. It has yet to be determined, however, whether this whole "having sex with a deer" thing is just a fad for the young monkeys, or whether these two species are planning to go the distance.
The monkey-deer sexual interactions reported here may reﬂect the early stage development of a new behavioural tradition at Minoo. Observational learning and social tolerance towards unusual sexual interactions are likely conducive to the expression, spread, and maintenance of other non-conceptive sexual behaviours in this primate species. Monkey-deer sexual interactions had never been noticed at Minoo before 2014. Future observations at this site will indicate whether this group-speciﬁc sexual oddity was a short-lived fad or the beginning of a culturally maintained phenomenon.
Macaques and Sika deer have engaged in symbiotic partnerships before, with the monkeys riding the deer for fun and transportation, while the deer benefit from the monkey's grooming and discarded food.
I guess macaques' smart phones come with the Grinddeer app.— Douglas Purdy (@dappestdap) December 18, 2017
Men are such pigs....🤣🤣🤣🤣— TrumpsTale (@EdGlen6) December 18, 2017
"...Some of the deer shook the monkeys off and fled the situation. But adult male deer...in particular...were likely to just stand calmly as the female monkeys thrusted. In some cases....the male deer kept eating......." pic.twitter.com/8ZRH22rrfF
well. Might be the weirdest story I’ve read this year— Colleen McKenty (@colleen_mckenty) December 18, 2017
Isn't science grand?