Although omnivorous, the Japanese macaque feeds mainly off plants: young shoots, flowers, fruit, root vegetables and mushrooms. But it also eats various insect species and, occasionally, invertebrates (crabs), and bird eggs.
In the wild, an average of six years. In captivity, up to 30 years.
Seasonal breeding. The female reaches sexual maturity around the age of 3 ½, the male at around 4 ½. Mating takes place in autumn and early winter. Gestation lasts almost 6 months (173 days). Birthing occurs in the springtime and summer, one suckling at a time, and weaning takes place at about one year.
Birds of prey, such as the mountain eagle; carnivores, such as raccoon dog, stray dog, and human being.