Researchers got footage of a monkey catching fish in a river. The Japanese macaque aka Macaca fuscata is an animal that usually feeds on leaves of bamboo and other woody plants during the annual cold season.
It is thought that, due to the difficulty of finding food amidst the extreme temperatures, the snow monkeys eventually ate aquatic organisms as food. An analysis of their feces also found evidence that around 20% of the faecal samples indicated that the monkeys had eaten fish.
Whether the monkeys were actively catching live trout or just scavenging for dead fish was unclear at first. Therefore, to investigate, the researchers followed the troop of monkeys along the banks of the Azusa River between January and March 2022.
"We were able to observe the behavior of Japanese monkeys catching active fish and consuming them 14 times, six times with direct observation and eight times with infrared sensor cameras," the study authors wrote.
"Including camera trap data, there are six other possible catches even though they cannot be confirmed as fish," he continued.
It is known that the monkeys consumed fish while alive. What researchers are trying to find out is how the Makaka monkeys started the habit of fishing. They investigated whether it was genetic or some sort of cultural spread among the groups. As a result, it was found that the animal accidentally caught the fish for the first time.
"We speculate that aquatic insect catching behavior may have been a pre-adaptive behavior for catching swimming fish. In fact, since the catching behavior of flowing water insects was frequently observed in this study, it is likely that the first fishing behavior occurred by accident." he said. This research has been published in the journal Scientific Reports as reported by IFL Science.