More Than 4 Billion Birds Stream Overhead During Fall Migration

Scientists use radar to shed light on the massive numbers of migrating birds and how many may not return
Ithaca, NY— Using cloud computing and data from 143 weather radar stations across the continental United States, Cornell Lab of Ornithology researchers can now estimate how many birds migrate through the U.S. and the toll that winter and these nocturnal journeys take. Their findings are published in Nature Ecology & Evolution.
“We’ve discovered that each autumn, an average of 4 billion birds move south from Canada into the U.S. At the same time, another 4.7 billion birds leave the U.S. over the southern border, heading to the tropics,” notes lead author Adriaan Dokter, an Edward W. Rose postdoctoral fellow at the Cornell Lab. “In the spring, 3.5 billion birds cross back into the U.S. from points south, and 2.6 billion birds return to Canada across the northern U.S. border.” Read more






