Mapping the Soundscape of the Rainforest

Alison Styring

With a Faculty Development Grant through The Evergreen State College Foundation, environmental studies faculty member Alison Styring has taken her research to the heights.

In early 2011, the International Year of Forests, Alison Styring spent several weeks in Borneo, home of the world’s oldest and tallest tropical rainforests. Considered among the planet’s richest and most threatened reservoirs of plant and animal life, these rainforests reverberate with the sustained music of hornbills, trogons, cuckoos, tree frogs, cicadas and countless other creatures. 

Thanks to the grant, Styring was able to embark on a new—and upward—path in the study of Bornean birds—one that could yield important information to help conserve the island’s poorly understood and fast-dwindling ecosystems. 

An ornithologist by training, Styring traveled to the Malaysian state of Sarawak, where intensive logging has taken a heavy toll, to survey the bird population in a protected remnant of Bornean forest. This work involved using highly sensitive audio-recording devices to capture bird songs in order to better understand the ecology of avian communities in disturbed and undisturbed landscapes. 

Styring’s project took place in a lowland dipterocarp forest, amid trees rising to nearly 300 feet in height. These giants are extremely valuable on global markets as timber for furniture and other uses, and once they are cut down, the island’s native forests are increasingly being converted to monoculture tree and oil palm plantations. 

What makes Styring’s bioacoustics inventory unique is that the recording occurred not just on the forest floor, which is where much of this type of work is done, but also high up in the canopy to gain a more comprehensive picture of the area’s bird life, from the ground to the treetops. Styring says many of the island’s bird species are so unfamiliar that no nest has ever been described for about 40 percent of them. The picture is even murkier for birds in the canopy. “We don’t have the baseline that we have for North American birds,” she says. 

Styring, who began studying birds in Bornean rainforests as a doctoral student at Louisiana State University in the late 1990s, says “We’ve been doing surveys in native and disturbed forests, but we started doing this work because we were concerned that we were missing a lot of information and action in the canopy.” And preliminary results from the latest research are indeed indicating that ground-based observations simply cannot grasp the full abundance of life that exists up in the treetops. 

Working collaboratively with students, birders, tree climbers and conservationists from the U.S. and Malaysia, Styring and her team used climbing techniques that she initially learned at Evergreen’s Canopy Lab. With one person on the ground and one person perched in the canopy several hundred feet up, simultaneous recordings were taken of a site. Afterwards, they are compared. Not only does this method help detect what’s missing, but Styring says it will help to see “if there’s distinct segregation between canopy and understory birds or overlap. Those are our main starting points. After we do more surveys, I’m hoping that if we get enough information, we can come up with some rule of thumb for how many birds are missing from ground surveys.” 

Although the survey data is still being analyzed, the team has discovered that there were significantly more species in the canopy. As the research proceeds and more surveys are done, Styring says they hope it helps to better inform conservation efforts and protect sites in the future. 

And she has taken the work back to Evergreen “to cultivate students interested in joining my bioacoustics lab and doing advanced research.” Once the Bornean recordings are parsed, correctly identified and edited, she wants to put them online. She also wants to do similar ornithological canopy research locally, at Capitol State Forest, for instance, and Nisqually and other areas around Olympia. 

The Foundation Faculty Development Grant she received was a tremendous help in underwriting this groundbreaking research in Sarawak, helping with travel, climbing gear, recording equipment, food and lodging during the pilot study. “I’m so grateful for the grant,” she says. “As a faculty member, I have little time to go for external grant money. It’s enough to keep our research going in the summer and during our spare time. But it’s extremely important as a professional and in teaching. It makes me a better mentor and teacher to my students.”