Fostering a Culture of Excellence
Using bioacoustics in conservation: How Malaysian researcher Dr Aini Hasanah is protecting our endangered gibbon populations
By Sim Wie Boon
Dr Aini Hasanah Mutalib, research officer at the Institute of Tropical Biodiversity and Sustainable Development at Universiti Malaysia Terengganu
Malaysia’s rainforests are alive with song—and Dr Aini Hasanah hopes to translate every single note to protect our endangered gibbon populations
A haunting melody breaks the silence in the early morning light filtering through the dense canopy of Terengganu’s Kenyir rainforest. Most visitors will never glimpse the musicians—endangered whitehanded gibbons and siamang—but their songs carry vital information about these elusive creatures that Dr Aini Hasanah Mutalib is determined to decode.
A research officer at the Institute of Tropical Biodiversity and Sustainable Development at Universiti Malaysia Terengganu, Aini’s journey into conservation began not with primates, but with marine turtles along the shores of Setiu, Terengganu.
“Wildlife conservation isn’t rocket science,” she quips, her tone wry. “It’s harder.” Her pivot to primatology was driven by Malaysia’s extraordinary—and often overlooked—biodiversity.
The country is home to 26 primate species, including the endangered gibbons and siamang, which she describes as “forest engineers.” These acrobatic apes, though lesser-known than orangutans, play a critical role in seed dispersal, nurturing the very ecosystems that sustain Malaysia’s rainforests.
“Imagine walking into a forest,” she says. “You might not see a tiger, but you’ll hear gibbons. Their songs are part of our national heritage.” This blend of ecological urgency and cultural pride underscores her mission: to elevate these “charismatic” species from obscurity to icons of conservation.
Lar gibbon (Photo: Alias Shakiri)
In 2021, Aini’s work gained momentum when she received the Merdeka Award Grant for International Attachment, enabling a three-month fellowship at Cornell University’s K Lisa Yang Center for Conservation Bioacoustics. There, she joined the lab’s eclectic “Yangsters”—researchers using sound to decode mysteries from deep-sea ecosystems to dense jungles. Collaborating with Dr Dena Clink, a specialist in Bornean gibbon vocalisations, Aini honed her expertise in passive acoustic monitoring (PAM), a non-invasive method that records wildlife sounds through autonomous devices.
“Bioacoustics flips the script,” she explains. “In forests or oceans, sight has limits. Sound reveals what eyes can’t see.” Deploying PAM devices across Kenyir’s fragmented habitats, her team now maps gibbon populations by analysing their dawn choruses—a far cry from traditional, labour-intensive field surveys.
“Gibbons and siamangs typically make sound or vocalise in the early morning towards the early afternoon. They will perform duets, with females typically making some loud calls. These calls are to mark their territory and they will vocalise loud and clear from the canopy. Different species make different types of “song” and you can tell from the song whether it is from a female or male individual,” Aini explains and adds that by tracking these sonic activities, researchers can map out parts of a forest that should be off limits and protected to keep these wild animals from outside danger. Early findings suggest that even degraded forest patches harbour these apes, challenging assumptions about habitat viability.
But the path to protecting Malaysia’s primates is fraught with nuance. Habitat loss, driven by deforestation and urbanisation, remains the gravest threat. “We want to know what kind of habitat we can prioritise so we can take actions to protect these species. I don’t think that people speak loudly enough about these animals,” she adds.
Yet Aini emphasises that solutions require more than ecology alone. “Conservation isn’t just science. It’s politics, economics, culture—and collaboration.” As co-founder of the Malaysian Primatological Society, she fosters partnerships between researchers, NGOs, and local communities. Workshops like BEAT (Bioacoustics Equipment and Training) and SIMBA (Symposium for Indonesia Malaysia Bioacoustics) empower Southeast Asian scientists with cutting-edge tools, while initiatives like LEAFA (Locally Led East Asian Flyway for Acoustics) integrate traditional knowledge with technology. “We’re not here to lecture,” she asserts. “We listen. Communities understand these forests intimately—they’re our greatest allies.”
Misconceptions, she notes, linger. Gibbons and siamang, often seen as “pests” when encroaching on plantations, are victims of human induced behavioural shifts. Feeding or photographing them up close, though well-intentioned, erodes their wild instincts. Aini adds that we often romanticise wildlife until it inconveniences us.
“We think that feeding primates can serve as a humane act, but actually, it would change the behaviour of the wildlife, making them more dependent and reducing their natural fear of humans. We see them as objects, and when it’s no longer “cute” or “adorable”, we throw them away,” says Aini.
Malaysian lar gibbon (Photo: iStock)
Looking ahead, Aini is optimistic. Advances in machine learning promise to automate sound analysis, scaling PAM’s potential. She also hopes for more resources and more studies across disciplines to be conducted with bioacoustics.
“There’s a library of sounds used to detect species of birds. They have that in foreign countries. So it is about time we have that in Malaysia as well. I heard there are people trying to do that here, and it’s a good way to start. I also have this idea of studying sounds and portraying them with the purpose of bringing inclusivity in science, where different people with different abilities will be able to do science as well. It is about time to get as many people to do science regardless of their different backgrounds and capabilities,” she says.
But at the end of the day, for Aini, the heart of bioacoustics remains elemental as she notes that listening is power. The songs that these primates and monkeys sing tell us a lot about forest health, climate shifts, and even our own future, so we protect ourselves by protecting them.
