Jigokudani Monkey Park is one of the most popular places to see Japanese macaques “in the wild”. The pools are man-made, having been constructed back in 1964 for the local snow monkeys to enjoy bathing in an onsen. They are fed daily by the park staff with a diet of raw barley and soy beans and can come and go as they please. This feeding regime is contributing to their survival as, otherwise, these ‘agricultural pests’ would seek their food from nearby farms with unfortunate consequences.
The International Union for Conservation of Nature (IUCN) has the monkeys listed on their Red List. These are some of their notes.
There are no major threats at the species level. There are two localities where hybridization with the introduced Macaca spp. is known to occur: Taiwanese Macaque (Macaca cyclopsis) in Wakayama Prefecture; and Rhesus Macaque (M. mulatta) in Chiba Prefecture (Abe et al. 2005). However, in the former case, most individuals have been removed (Watanabe pers. comm.). Each year, over 10,000 individuals are killed to prevent agricultural damage (Abe et al. 2005), and this situation may require more careful population management.
We were here on a very warm late spring day, and unlikely to see any swimming in the onsen. Mostly the monkeys were foraging around for food, or sleeping or having the occasional spat. There were new babies to see. After a while, the adolescents decided that a hot swim on a hot day was a good idea after all.