The Sierra Nevada project

With over 1,600 recording units and over 25,000 square kilometers of survey coverage (over 9,000 square miles, or slightly larger than the state of Vermont), this is the first and most comprehensive ecosystem-scale passive acoustic monitoring project in the Western Hemisphere.

Origins & Motivation

The project began in 2016 to address a major gap in bird conservation information: what is the status of the invasive Barred Owl in the Sierra Nevada?

In the summer of 2021, survey coverage was expanded to the entire Sierra Nevada. Seven National Forests, three National Parks, and over 25,000 square kilometers.

Hardware & Software

Every single unit in the project was built by hand here at the Lab.

Generates over 1,000,000 hours of audio per year.

BirdNET algorithm.

Bird Conservation

Spotted Owl

Experimental Barred Owl removals.

Acoustic monitoring.

Mountain Quail

First ever intensive ecosystem-scale monitoring effort, first study of this species in 36 years. Unexpectedly common.

Olive-sided Flycatcher

Identified a plausible cause of their declines.


Toads, frogs, wolves, coyotes