The previous post was walking in and walking back so here we are at the famous hot pool frequented by the “snow monkeys”.

Hot and steamy….

The monkeys are in fact Japanese Macaques and are the most northerly-living primates apart from the ones known as homo sapiens.

We are in a secluded mountain valley.  The monkeys have been frequenting the hot springs here since 1963 only, when a female macaque named Mukubili dived in to fetch some soy beans and decided she liked it in there.

Some decades ago, the prevailing theory was that only humans were able to benefit from learned behaviour.  A female Japanese macaque called Imo disproved this.

Researchers left sweet potatoes on a beach so they could lure the macaques out into the open and observe their behaviour.  At first they all brushed off the sand before eating them.  Imo found that a more successful method was to dip the sweet potatoes in a fresh water stream.  Then she found the taste improved if she dipped the sweet potatoes in sea water as she ate them, for a bit of salt seasoning.  Later she found that if she made a ball of sand and wheat and put it in the fresh water, the wheat would rise to the surface and she could eat it free from the sand.  In each case, first her offspring picked up this behaviour, then other females, then the whole troupe.

Japanese macaques are diurnal (they sleep during the night) and they are sexually dimorphic (males are bigger than females).  They are primarily fruit eaters and also eat leaves, seeds, nuts, bark, mushrooms, insects, snails, crabs and crayfish according to the season and availability.

Females bear one young one at a time, which they raise for two years so that they can be taking care of an older one and a younger one at the same time.  The young start by clinging on underneath, then after a few months graduate to riding on their mother’s back.

Japanese macaques live for 25 to 30 years in captivity and 8 to 10 years in the wild.   They live in troupes of usually 20 to 30 individuals and their society has strong matrilineal characteristics.

There are around 100,000 macaques in Japan and they are classified as endangered.   They are widespread amongst the islands but do not range as far north as Hokkaido.  Thousands are killed by farmers very year, notwithstanding their protected status.  Other predators include wild dogs, mountain hawk eagles and possibly raccoon dogs.  They are also susceptible to habitat loss (forests).