A Beneficial Relationship

Just like us, the monkey

folds its arms on its chest

in the cold autumn wind

Haiku by Chinseki

On the island of Yakushima, south of Kyushu, Japan, in the ancient Yakusugi Forest, Japanese macaques (Macaca fuscata yakui) and sika deer ( Cervus nippon yakushimae) interact in rather unusual ways.  Both mammals feed on the black, berry-like fruit of the camphor tree.  Macaques often drop fruit (and feces), thus providing food for the deer that forage beneath the trees.  And the macaques tend to ride, for short distances, on the backs of the deer, at times grooming the animals to get rid of lice, which are a rich source of proteins.  Research scientists from Kyoto University studying the feeding behavior of the deer, found a possible example of interspecies communication, since the deer tend to gather in areas where the macaques are feeding, after apparently listening to the monkey calls.  And, more recently, French primatologists studying the behaviors of Japanese macaques, have observed a male macaque possibly attempting to mate with a female deer.  It is thought that in riding the deer, the macaques may be taking a known play behavior a step further.


See also:

“Primates”, April, 2017. vol. 58, issue 2, pp. 275-278, “Interspecies Sexual Behavior Between a Male Japanese Macaque and Female Sika Deer.”  Authors: Marie Pele, Alexandre Bonnefoy, Masaki Shimada and Cedric Sueur.      https://link.springer.com/article/10.1007/s10329-016-0593-4

The Japanese Macaques, N. Nakagawa, M. Nakamichi and H. Sugiura (eds.), N. Y.: Springer, 2010.

Sika Deer, D. R. McCullough, S. Takasuki and K. Kaji (eds.), Tokyo: Springer, 2009.

New research on spider monkeys – coping with anthropogenic disturbances

Michelle A. Rodrigues, Anthropologist at University of Illinois, researched the impact of anthropogenic disturbance on spider monkeys at El Zota Biological Field Station in Costa Rica and recently published her findings in the International Journal of Primatology.  She reaches the following conclusion:

“spider monkeys cope with variation in fruit abundance by adjusting subgroup size, and that these adjustments may mitigate environmental stress in this mildly seasonal environment. The large, relatively productive forest size at this site, and the availability of anthropogenic food sources, enable this population of spider monkeys to cope with human-induced habitat disturbance.”

You can read Rodrigues’ article (published in July 2017) for further details.