Sex Between Snow Monkeys and Sika Deer May be 'New Behavioural Tradition'
Sexual interactions between snow monkeys and sika deer could be a new behavioural tradition within a group of monkeys observed in Japan, researchers have suggested.
While the first report of a male Japanese macaque, or snow monkey, and female sika deer taking to each other was revealed earlier this year, scientists say they are now confident the behaviour is sexual after scrutinising adolescent females suggestively interacting with stags at Minoo in Japan.
“The monkey-deer sexual interactions reported in our paper may reflect the early stage development of a new behavioural tradition at Minoo,” said Dr Noëlle Gunst-Leca, co-author of the study from the University of Lethbridge in Canada.
While sexual interactions between closely related species have been seen for all manner of animals, from various species of fish to species of baboon, such liaisons are rare, with the sexual assault of king penguins by Antarctic fur sealsthe only other known example between distant species.
But earlier this year, a study revealed a male Japanese macaque had been filmed mounting a female Sika deer at Yakushima island in southern Japan. Gunst-Leca said it wasn’t clear quite what was going on.
“They were dealing with a single anecdotal event between one individual monkey and one individual deer, and the description they provided was short, vague and out of context,” she said. “As a result, even the sexual nature of this interaction was not clearly demonstrated.”
In the latest study, published in the Archives of Sexual Behavior, Gunst-Leca and colleagues describe how they sought to unpick whether the intentions were indeed carnal.
To investigate, the team recorded the behaviour of snow monkeys at Minoo, north of Osaka in Japan. With only adolescent female monkeys spotted mounting deer, the team compared the interactions to sexual interactions between adolescent female monkeys. The latter is a well known practice, and the only available comparison, as during the study adolescent females were not seen performing sexual mounts on adult male monkeys.
In total, the team recorded 12 successful interactions between monkeys, involving six adolescent females, between November 2012 and January 2013 – with a total of 67 mounts by the monkeys. In addition, 13 successful interactions of an apparently sexual nature were recorded between monkeys and deer between early November 2014 and January 2015, involving five adolescent females and a total of 258 mounts.