Thai Monkeys May Abandon Stone Tools Due to Human Disruptions

Human disturbances in Thailand’s Laem Son National Park may be causing Burmese long-tailed macaques to abandon their use of stone tools, say researchers studying the primates. The only monkeys in Asia to use stone tools — and one of only three non-human primates worldwide to do so — these Burmese macaques have learned to use coastal rocks to crack the hard-shelled crabs, snails, and oysters that make up their diet. Habitat loss to rubber and oil palm farming, competition with humans for food sources, and threats from domestic dogs are forcing the macaques to change their foraging habits, researchers from Singapore’s Nanyang Technological University report. The monkeys are also showing signs of acclimating to humans and becoming dependent on human food sources.