Scientists are heralding what may be a sign of the coming Apocalypse. Researchers have recorded for the first time ever two animals from totally different species having consensual sex.
The strange behavior is documented in a new paper that describes sex between a male Japanese macaque and female sika deer in Japan.
The paper describes what is thought to be one of the first ever recorded instances of "reproductive interference" between two very different animal species.
Sex between two totally different species is rare in nature because -- unlike humans -- most animals have sex for reproductive purposes only. Animals of different species cannot reproduce.
According to the paper, the monkey "showed clear sexual behavior towards several female deer" who tried to flee his sexual advances.
But one of the deer apparently consented to the odd behavior and "accepted the mount", the researchers wrote in the journal Primates.
The researchers wrote that one deer "seemed to accept to be ridden by the male macaque" monkey, and that it was apparently licking sperm that had been deposited on its back by the monkey. Another deer refused the mount and threw the [monkey] off its back.
The scientists note that it is common for monkeys to hitch rides on the backs of deer. But it is unlikely for a monkey to have sex with the deers.
There have been reports of sexual activity between confused animals of different species that are born and bred in captivity. But the behavior has never been observed in the wild.
The scientists hope further study can shed some light on why humans show a sexual interest in animals.