Acoustic monitoring network for birds enhances forest management

March 11, 2025

New Technology Helps Forest Managers Protect Birds in California's Sierra Nevada

ITHACA, NY —Scientists have found a new way to track forest birds using thousands of microphones, helping them better protect both wildlife and forests in California's Sierra Nevada mountains. The research, published today in Frontiers in Ecology and the Environment, demonstrates how emerging bioacoustic technology can enhance wildlife monitoring and forest management.

Researchers at the Cornell Lab of Ornithology’s K. Lisa Yang Center for Conservation Bioacoustics analyzed more than 700,000 hours of bird sounds recorded across California's Sierra Nevada. The team deployed microphones at 1,600 sites spanning approximately 6 M acres of Sierra Nevada forest to track 10 important bird species, including owls and woodpeckers, that can tell us about the forest's health.

"The amount of coverage that gives us and the idea of what's happening with species at so many different locations allow for really powerful inference to be drawn from the network," said study lead author Kristin Brunk, a postdoctoral associate at the Yang Center.

Using automatic microphone recording units and BirdNET, a machine-learning algorithm, they analyzed the recordings to identify different bird calls and studied how these birds relate to various forest conditions, such as how many trees are in an area or how dense the forest canopy is—variables that managers commonly use in their planning processes.

This information is particularly valuable now, as forest managers face tough decisions about preventing destructive wildfires while protecting wildlife. The study creates detailed maps showing where different birds are likely to live, helping managers make better-informed decisions about where to thin forests or conduct controlled burns.

"We're able to understand bird populations in the context of the forest conditions that are going to be actively manipulated by the management community to hopefully restore some resilience to this system," said Connor Wood, lead researcher at the K. Lisa Yang Center for Conservation Bioacoustics.

This approach proves remarkably cost-effective compared to traditional wildlife surveys. "If you think about what the cost would have been to get that amount of information by having biologists collecting data across the landscape... the cost effectiveness can't really be matched," Brunk noted.

The study also serves as a model for wildlife monitoring in other regions facing similar challenges. "It's sort of a blueprint for how passive acoustic monitoring can inform management," said Brunk.

"By combining new technologies with practical management needs, we're creating tools that can help protect both forests and wildlife during a time of rapid environmental change,” said Wood.

The research was conducted in collaboration with the U.S. Forest Service, University of Wisconsin-Madison, Oregon State University, University of California-Merced, and Chemnitz University of Technology.

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Brunk, K. M., J. F. Goldberg, C. Maxwell, M. Z. Peery, G. M. Jones, L. R. Gallagher, H. A. Kramer. A. L. Westerling, J. J Keane, S. Kahl, and C. M. Wood. (2025). Bioregional-scale acoustic monitoring can support fire-prone forest restoration planning. Frontiers in Ecology and the Environment. https://doi.org/10.1002/fee.2843