On May 21, Ryma Benayed was walking to a subway entrance near Central Park when she spotted 14 Cedar Waxwings lying yellow-belly-up by a building. “It looked so strange that at first I thought it was a magic trick, so I got closer to see,” she says. “That’s when I understood that they were dead.” Later that day, Benayed, a technical director at Memorial Sloan Kettering Cancer Center, Googled around for the story. She couldn’t find a thing. “All of these birds die and no one talks about it?” she says. “I was shocked.” What Benayed’s Googling did unearth was a dead-bird database developed by New York City 蜜柚APP. She submitted a photo of the birds and the date, time, and location where she found them. “I’ve never reported anything before, but this time I felt like I had to,” she says. Benayed’s report was one of 91 submitted to D-Bird during spring migration, an especially deadly time for birds. It’s estimated that 250,000 birds die by...