Every year, billions of birds migrate thousands of miles from their summer breeding ranges to their warmer wintering ranges and back. However, the question of where these birds stop to rest and refuel along the way has long stumped ornithologists. Princeton Ph.D. student Fengyi Guo and her colleagues from Princeton and the University of Delaware address this question in a newly published paper by using weather radar imagery to map the birds’ migratory stopover sites in North America.   

The radar imagery showed that stopover hotspots along the eastern U.S. consist primarily of deciduous forests, including forest fragments in broadly deforested regions. These hotspots serve as crucial pitstops for large numbers of landbirds each year. Protecting these sites helps to ensure the long-term viability of all the bird species that sojourn at these sites.

“Fengyi’s work using weather radar images of migration provides us with the first accurate picture of where the key stopover sites for these birds are across the eastern United States.” said David Wilcove, a C-PREE faculty member and co-author of the paper. “This information is incredibly important. Without it, we wouldn’t know which sites to protect to ensure safe passage for the birds.” 

Since 1970, migratory bird populations have plummeted by more than a quarter in the United States, a loss attributable to a host of human-induced factors including habitat loss, overexploitation, and climate change. In their paper, the authors emphasize the importance of protecting key habitats