It is early morning on the island of Borneo in east Malaysia, and the ancient rainforest is coming to life after the relative quiet of the night. It’s a veritable orchestra: the melodious music of a pair of gibbons, a warning trumpet from a solitary pygmy elephant, the rhythmic hooting of a helmeted hornbill, the rustling of dry leaves from an orangutan swinging high up in the trees. In the midst of these routine, reassuring sounds, other sounds filter through. There is an unfamiliar chirp — a new species of bird? Occasionally, there comes a noise that does not belong in this ecosystem — perhaps the insistent buzz of a chainsaw? There may even be moments of silence, a sign of disruption in the usually bustling habitat. The tropical rainforests of Malaysia are among the world’s oldest and richest in biodiversity. They are home to thousands of species of plants, insects, birds, mammals and reptiles, many of which have still not been studied adequately, or even discovered. And many of them are hurtling toward “threatened” or “endangered” status on the International Union for Conservation of Nature’s red list.  Malaysia’s rainforests are home to a rich array of wildlife. Credit: SAFE Acoustic Project Scientists and researchers continuously monitor the flora and fauna in these jungles in order to ensure that the ecosystem remains healthy — in the face of threats from both natural disturbances and anthropogenic pressures (including climate change). Now, they’ve added a new and effective tool to their arsenal: listening. Through bioacoustics research, researchers are tuning in to the sounds of the rainforests in Borneo and peninsular Malaysia to better understand and protect their biodiversity. Reasons to Be Cheerful · Borneo rainforest sounds (SAFE Acoustic Project)   While traditional monitoring systems involve identifying and documenting species mainly by sight, bioacoustics uses technology to collate, identify and analyze sounds from all the living organisms within the ecosystem. Recording devices collect and convey real-time soundscapes from both primary forests (which have never been deforested and replanted) as well as areas where there is a lot of human activity in the form of logging and palm oil production. Taken together, these soundscapes are a reliable indicator of the health of the ecosystem. Bioacoustics research may still be in its nascent stages (especially in Malaysia), but it has caught on across the world because it manages to capture data about birds and animals that are camouflage experts or near impossible to spot in the wild. And this method has another advantage: sounds are unique to species.