Sex between snow monkeys and sika deer may be 'new behavioural tradition'

Following a report of monkey-deer interactions earlier this year, researchers have now recorded the behaviour in another group of monkeys

Nicola Davis

Friday 15 December 2017 14.20 GMTLast modified on Friday 15 December 2017 22.01 GMT

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 seals the 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.

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