Strange behavior researchers captured video footage Monkey sex with female Sika deer. Researchers captured a Japanese macaque male mounting a female Sika deer.
The monkey does not penetrate the deer, but does ejaculate on its back.
A hormonal surge in the monkey during breeding season may have resulted in the strange behaviour.
While most animals tend to mate with members of the same species, researchers have captured the bizarre moment two very different animals became intimate.
Video footage shows a Japanese macaque male mating with a female Sika deer.
Thisonly the second time two animals of unrelated species seen mating, since a fur seal was filmed mating with a king penguin in 2014.
The strange situation was captured by researchers from the University of Strasbourg in France.
While filming on Yakushima Island south of Japan.
Japanese macaques comfortably live side-by-side with Sika deer, and the deer often eat food that the monkeys dropped, or even monkey faeces.
While some macaques have been seen grooming the deer or riding them in a playful manner, they have never before been known to mate.
Strange behavior researchers captured video footage Monkey sex with female Sika deer.
But in November 2015, researchers observed a healthy adult male macaque attempt to copulate with at least two different female Sika deer by performing sexual mounts on the animals’ backsides.
Alexandre Bonnefoy, co-author of the study, said:
‘The male mounted the deer and displayed some copulation behaviors.
Which included about 15 sexual movements over a period of 10 seconds, before dismounting.
‘This might indicate that the sperm could be a good source of protein to the deer.’
While the macaque did seem to ejaculate, the researchers note that penetration did not occur.
As the penis directed at the back and not the genital area of the deer.
The researchers suggest that it might explained by the difference in the build and size of the animals involved.
The male monkey also tried to mount a second female deer, but without any success.
She attempted to escape, and tried to get rid of the monkey by moving faster, turning around and displaying threatening behaviour.
Strange behavior researchers captured video footage Monkey sex with female Sika deer.
The monkey went on to display a form of mate-guarding behaviour in that he chased other peripheral males away from the deer under his watch.
The researchers believe the hormonal surge experienced by the Japanese macaques during breeding season.
And the close cooperation between these primates and Sika deer culminated in this copulation behavior between two unrelated species.
Marie Pelé who led the study, said: ‘It could also be a sexual manifestation of the known play behavior.
Between Japanese macaques and the deer they known to sometimes ride.’
This the second time that animals of unrelated species seen mating.
In 2014, an Antarctic fur seal seen coercing king penguins into sexual relations in Antarctica.
But according to lead author Ms Pelé, the interaction observed in Japan differed from the Antarctic case.
As it involved sexual interaction without penetration, and also included mate guarding by the monkey.
