Scientists Say Japanese Monkeys Are Having 'Sexual Interactions' With Deer
Researchers witnessed adolescent female Japanese macaques mounting sika deer in ways that were "sexual in nature." They have several theories for why but say more research is necessary.
Japanese macaques are known to ride deer like humans ride horses, for fun or transportation — behavior the deer seem to tolerate in exchange for grooming and discarded food. But these monkeys were up to something different.
The researchers compared the monkey-deer interactions, which happened during mating season, with homosexual monkey-monkey interactions, where female macaques mount each other. They paid close attention to the “mounting postures” the monkeys assumed on the deer, and the vocalizations they made, to determine that the interactions were, in fact, sexual … at least for the monkeys.
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.
There were eight failed attempts as well. In some of those cases, the monkey-deer interaction was interrupted because another young female macaque came along, “successfully displaced the original adolescent female mounters and took over the deer to start their own heterospeciﬁc consortships,” the researchers noted. That was not a plot twist they had anticipated.
And the interactions went beyond the mere moment of thrusting. The “monkey-to-deer solicitations … were persistent and conspicuous,” the researchers write. Young female monkeys would identify a “particular target” and make calls that sound identical to the ones in monkey-on-monkey courtship.
If the deer avoided the interaction, “the female monkeys often displayed sexually motivated tantrums which consisted of crouching on the ground, body spasms and screaming, while gazing at the deer,” the study found.
I blame the anime.