Science

Researchers Surprised By Monkeys Having Sex With Deer

In a bizarre finding, researchers in Japan have observed monkeys having sex with deer.

Monkeys Having Sex With Deer
Image source: YouTube Video Screenshot

The Monkeys

A video released a while back that seemed to show monkeys having sex with deer, and new research published in the Archives of Sexual Behavior confirms this strange observation.

To follow up on the viral video that had the world scratching their collective heads, scientists traveled to the Meiji Memorial Forest in Japan from November 2012 to January 2013 and then again from November 2014 to January 2015 to observe the behavior of Japanese macaques and see whether or not these claims were actually founded.

It turns out that the video was legitimate, and that female monkeys are actually acting in a sexual manner towards sika deer.

The study noted that the encounters were “sexual in nature,” with authors writing that “this is the first quantitative report of heterospecific sexual behavior between a non-human primate and a non-primate species under free-ranging conditions.”

Over the course of the time spent studying the Japanese macaques, researchers observed 13 instances of monkeys having sex with deer in the few months stationed in the forest. Apparently, female monkeys would mount the deer and rub against them in encounters that lasted between 3 seconds and 42 seconds each.

The bizarre video that made its rounds on the web now has documented research behind it, but why this weird situation is occurring is currently anyone’s guess.

Why Are Monkeys Having Sex With Deer?

The paper didn’t give many details on why exactly the interactions were happening, and the whole situation has left researchers stumped. Several theories suggest that perhaps the monkeys were practicing their sexual behaviors on the deer, or that they were seeking out more docile partners in place of aggressive male macaques. Another possible explanation is the fact that males tend to prefer older females, leaving young macaques without sexual partners.

These findings, while bizarre, give some insight into the behavior of species that are evolutionarily quite similar to humanity. As mentioned above, primates (outside of humans) have never before been seen engaging in sexual behavior with a non-primate species.

Primates are incredibly complex and intelligent and are one of the few documented species that have sex for pleasure. The fact that female macaques are seeking partners outside of their species is unprecedented and gives us a closer look into the multifaceted world of primate sexuality.

The study’s abstract closed as researchers posed the question of what exactly the implications of this strange event are for the study of animal sexuality.

“Further research will be necessary to ascertain whether this group-specific sexual behavior was a short-lived fad or an incipient cultural phenomenon and may also contribute to better understanding the proximate and ultimate causes of reproductive interference”

At the current moment, it’s a bizarre behavior caught on tape that has now simply been documented in an academic research journal. Further exploration into why exactly there are monkeys having sex with deer may give us a better understanding of this yet-unexplained phenomenon.