Science & Technology

Scientists find Japanese macaques going fishing to survive the harsh winter

Credit: University of Birmingham.

Japanese macaques, who live in one of the coldest regions in the world, survive by “going fishing.” New research has emerged to scoop live animals such as brown trout from rivers in Japan and eat them to stay alive.

Snow monkeys (Japanese macaque Macaca fuscata) grow naturally on major islands in Japan except Hokkaido.

The northernmost non-human primates have found that snow cover limits the availability of their favorite foods in the Kamikochi region of the Central Mountains National Park of the Japanese Alps.

Snow monkeys lack energy and face death from starvation because it is difficult to find their favorite food, but the stream supplied with groundwater flows at a constant water temperature of about 5 ° C during the winter, replacing Japanese macaques. Easy-to-access food to look for live food.

An international research team led by experts at the University of Birmingham today published its findings in Scientific Reports. This is the first scientific paper to ensure that Japanese macaques eat freshwater animals, including brown trout, in streams.

Previously, Japanese macaques have been shown to opportunistically catch marine fish when dried or washed off the beach, but closely related species have been shown to feed on freshwater fish. ..

Researchers have found brown trout in Japanese macaque fecal samples and believe that macaques are catching brown trout in shallow pools along the edge of the stream.

Experts used meta-barcodes from fecal samples to determine the monkey’s winter diet and found that animals also eat river insects and mollusks. This is an additional source of food that may help with winter survival.

Alexander Milner, a professor of river ecosystems at the University of Birmingham, who led the study, commented: The population density is very high and macaques need to overwinter in very harsh environments.

“A large population of these people creates additional stress to survive the winter, but the abundant groundwater upwelling from active volcanoes and the influx of hot springs cause many streams to flow uncovered by ice, and monkeys. Easy access to.

“Because of the abundance of freshwater animals in rivers and streams, Kamikochi may be the only environment in Japan where Japanese macaques can thus supplement their winter food due to topographical, geological and meteorological conditions. not.”

Researchers have also found evidence of freshwater insects in macaque fecal samples, such as aquatic insect larvae and nymphs.

Terrestrial insects are the main source of food for Japanese macaques, especially in the summer, but this is the first confirmed record of aquatic insect larvae and nymph feeding.

Scientists find Japanese macaques going fishing to survive the harsh winter Scientists find Japanese macaques going fishing to survive the harsh winter

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