Most songbirds migrate in darkness, usually when weather conditions are favorable. Tailwinds can produce massive migratory movements. Rain can shut down flights entirely.

“Knowing when and where a large pulse of migrants will pass through is useful for conservation purposes,” says Benjamin Van Doren, a former Cornell undergraduate and now Ph.D. candidate at the University of Oxford. “Our forecasts could prompt temporary shutdowns of wind turbines or large sources of light pollution along the migration route. Both actions could significantly reduce bird mortality.”

“This is the most significant update since we first began using radar to study bird movements,” notes Cornell Lab postdoctoral associate, Kyle Horton. “From the bird watcher’s perspective, if you know where and when migrants will be flying at night, you stand a better chance of seeing them, especially if the birds make a stopover in your area.”

Van Doren and Horton designed the system that generates the migration forecast maps. They used machine learning models based on 23 years of radar and weather data to predict suitable conditions for migration occurring three hours after local sunset.

“These forecast and live migration maps, and the research that produced them, represent a breakthrough nearly 20 years in the making,” adds Cornell Lab migration researcher Andrew Farnsworth. “We hope these maps will provide perspective to the expert and novice alike on the amazing spectacle—and the sheer magnitude—of migration. Beyond that, we believe these maps will become powerful tools for conservation action to help reduce the impacts of human-made hazards birds face during their incredible journeys.”

This research was supported by funding from the National Science Foundation, Leon Levy Foundation, and NASA. Additional funding was provided by the Edward W. Rose Postdoctoral Fellowship at the Cornell Lab of Ornithology, Marshall Aid Commemoration Commission in the United Kingdom, and Amazon Web Services Cloud Credits for Research.

The BirdCast project is a collaboration among the Cornell Lab of Ornithology, University of Massachusetts Amherst, and Oregon State University, and was funded by grants from the National Science Foundation and Leon Levy Foundation.