Habits of Snow Monkeys Searching Fish to Survive Winter.
By Masaki TAKENAKA, Kosuke HAYASHI, Genki YAMADA, Takayuki OGURA, Mone ITO, Alexander M. MILNER, and Koji TOJO
A few yr in the past, in November 2021, our analysis group printed a paper on the likelihood that Japanese macaques within the Japanese Alps (Kamikochi) area catch and eat fish in winter (Milner et al., 2021, Scientific Studies). About 200 Japanese macaques in 4 troops dwell within the Kamikochi area. Kamikochi is a sub-alpine zone (1,500–1,600 m altitude) the place the temperature drops beneath -20°C in winter. The snow monkeys of Kamikochi dwell within the coldest areas of all primates, aside from people. It was an attention-grabbing problem to achieve an understanding of how they handle to outlive within the winter when meals is so scarce.
After we printed our paper a yr in the past, we solely had oblique data indicating a food regimen together with fish based mostly on brown trouts’ DNA which was detected within the feces of a number of people via metagenomic evaluation performed on the feces of snow monkeys collected over a number of winters. At that time, the likelihood remained that that they had been scavenging for leftover meals from mountain climbers in winter. Nonetheless, after the publication of that paper, many media retailers coated our paper, which vastly elevated public curiosity. Quickly after, a collection of photos had been supplied to us by two cameraman who had taken pictures of snow monkeys in Kamikochi as they had been biting and consuming fish. Since these photos additional superior our analysis understanding, we quickly printed extra articles on this “Nature Portfolio” web site (January 1st, 2022; Figs 1–2). At this stage, snow monkeys’ fishing was virtually sure, but the one regretful factor was that nobody had really witnessed the decisive second of their fishing. Nonetheless, this vital difficulty was lastly resolved by means of the collaboration of our analysis group and an NHK movie crew (Figs 3–5).
By way of our analysis and filming from January to March 2022 lastly, the snow monkey’s precise second of fishing was captured on digicam (Fig. 3). This meant that the fishing conduct of monkeys had been recorded for the primary time ever. This fishing was not particular to a particular particular person, and a number of monkeys in not less than three troops had been efficiently in fishing. In whole, 14 scenes had been filmed of verified fishing, together with an extra 6 presumed instances of fish predation. It may be thought-about that there’s positively a longtime “fishing tradition” inside not less than three troops. Our paper additionally considers the evolutionary course of by which snow monkeys’ tailored fishing which can have led from aquatic herbivory after which anb aquatic insect food regimen after which to a fish inclusive food regimen.
This paper publishing our one-year replace on the analysis so far (Takenaka et al., Scientific Studies) notes that though we performed an in depth evaluation of fishing time zones and climate situations, we didn’t observe any clear tendencies associated to environmental situations. Additional collaborative analysis with the NHK movie crew can be deliberate for the upcoming winter season (2022–2023 winter). At present, in collaboration with researchers who specialize within the behavioral ecology of primates, we are attempting to determine and observe particular snow monkeys individually. We wish to make progress to additional replace our data and understanding of the attention-grabbing conduct and ecology of those snow monkeys.