As Indonesia constructs its new capital, Nusantara, in the mountains of East Kalimantan in Borneo, the roar of chainsaws interrupts the rainforest sounds that have long been part of the cultural heritage of the Indigenous Balik community. New documentary, Sound Guardians, a collaboration between Mongabay, Scientific American and Project Multatuli, follows efforts by scientists and local residents to capture this shift in sounds.
Former President Joko Widodo spearheaded moving Indonesia’s administrative center away from Jakarta, the world’s fastest-sinking city. Experts estimate that one-third of Jakarta could be underwater by 2050 owing to sea-level rise and excess groundwater pumping. Official marketing describes Nusantara as a “smart forest city” projected for completion by 2045.
Wendy Erb, a bioacoustic scientist from the Cornell Lab of Ornithology in the U.S., who has worked in Kalimantan for a decade, is leading the work to record the sounds of the forested landscape as the capital gets built.
Her team has recorded sounds in diverse areas, from mountain tops to mangroves and caves. Erb describes this data as a “time capsule” that allows for comparisons as the environment changes with rapid economic growth and construction.
This data could potentially show places where wildlife is being displaced, Erb suggests in the film. “Maybe those are places where more investment could be made in conservation efforts,” Erb said.
“The question is, can we tune our ears?” Erb adds. “Can we pay attention? Can we notice when the natural world is feeling a little sick?”
For Abidin, a member of the indigenous Balik community and a resident of Pemaluan, a village within the territory incorporated into Nusantara, the forest sounds are intrinsic to survival and tradition. He says that the community’s ancestors used gibbon calls at dawn as spiritual signs, but today younger generations are losing this connection. Abidin explains that species such as the Great Argus (Argusianus argus) are now rarely seen or recognized by children.
“Our people say that usually the chainsaw is the loudest,” Abidin says, highlighting the shift from natural melodies to the sounds of development.
What was once largely forest now features apartment buildings, a hotel and a new presidential palace. But the future remains uncertain: In 2025, Indonesia’s new president slashed the budget for the capital, though construction continues.
Abidin, Erb and other partners are creating a book about Balik biocultural heritage and developing a platform for the communities to access and use the sound recordings.
Abidin says he fears being able to adapt to city life, “If we become scavengers in our own hometown, it’s better to just die.”
Nevertheless, he remains committed to teaching his children the language of the forest. “Even though there are changes now, I still feel that this is my home,” he says.
Watch the video by Leah Varjacques, Rizky Rahad and Sandy Watt here.
Banner image: Abidin, a Balik elder, listens to forest recordings. Image courtesy of Sound Guardians film.
