SONAR (Southern Ornithology Network for Applied Research) is a distributed network of autonomous acoustic recording units (or “nodes”), each operating on compact Linux-based processors. These nodes are designed to capture and analyze bird vocalizations both during the day and at night. The system integrates three key open-source software components: Nighthawk for detecting nocturnal flight calls (NFCs), BirdNET for identifying bird species from diurnal vocalizations, and sonaR, a new CNN audio classifier for NFCs and wildlife vocalizations (Contina et al. in prep.). Our sonaR software includes a set of custom-built R and Python scripts to manage, process, and organize the data across the network. SONAR Viewer is a web interface for real-time data display and spectrogram validation to support sonaR model training.
Current deployment
In 2025 we deployed a total of 15 SONAR nodes throughout the lower-Rio Grande Valley, south Texas, and Austin (see map below). In just the first few months, we have already recorded thousands of hours of audio, detected thousands of nocturnal flight calls and diurnal vocalizations, and detected dozens of species. Already we are seeing region-specific differences with the national classifiers and have regularly updated our sonaR classifier by validating calls.
Future Plans
We anticipate expanding the network in the future to build a comprehensive understanding of migration, habitat use and stopover ecology. By the spring 2026 migration season, we hope to have up to 20 nodes in place that will help us cast a net(work) across Texas.
Do you want to join our project?
We are seeking collaborators to host our SONAR nodes. Currently, we have nodes deployed on University grounds, field stations, state parks, and private lands. We need open outdoor spaces with nearby access to electricity, steady WiFi, and limited noise pollution. We have found that noise pollution from air conditioners, roads, and wind, as well as radio-frequency signals can each interfere with our acoustic recorders to a degree.
Depending on funding availability, we may be able to deploy at your site free of charge. Alternatively, please consider donating to the project (a single unit costs about $150-180) and we will provide everything needed for the node and can set up a new site in roughly 30-45 minutes. Each node will start collecting data and transmitting it to SONAR Viewer the next day, and the recordings will be incorporated into model validation steps within 2-weeks. This means that your contribution will have an immediate impact on our monitoring efforts and will help to refine the classifier and improve detections moving forward.
