Japanese Monkey (Macaca fuscata yakui ), also known as macaques, have recently been observed by biologists that they can ride on the head and back of sika deer (Cervus nippon yakushimae). These two species have coexisted peacefully in the forests of Japan for a very long time. The relationship between them is extremely close and always mutually beneficial: the deer eat the nuts and fruit dropped by the monkeys in exchange for the monkeys being able to groom and remove parasites from the deer people (section). The main purpose is to collect salt on the body of the deer). Sometimes, the deer also accept these monkeys riding on their back to move when they go along the road.
However, scientists have discovered that the friendship of these two animals is more than just observations and eye contact.
The researchers found that the dynamics of this mutually beneficial relationship between monkeys and deer began to shift to a somewhat perverted approach, with the monkeys starting to see deer as their own kind. .
One of the first times this behavior was observed by scientists was on the island of Yakushima, Japan, in 2015, when a low-level male monkey attempted to ride at least two different female deer. While one of the two deer did not notice the monkey making movements on its back, the other one noticed and ran away.
Between 2012 and 2015, another team of researchers delved into the odd behaviors of Japanese macaques. Overall, they recorded a total of 258 deer rides at Minoo, north of Osaka, Japan. Interestingly, however, only young female monkeys have been spotted riding sika deer.
Lead author Noëlle Gunst told Inverse that there are various theories about the key factors behind the monkey-deer relationship. One theory is that the Japanese macaques may have experienced a special kind of stimulation when riding and grooming the deer, so that over time the monkeys came to regard the deer as their own species.
However, the authors note that none of the above explanations is just conjecture, with no scientific basis, and that this behavior may be a new habit of Japanese monkeys.