Avian ecologist and Georgetown University Ph.D. student Emily Williams releases an American robin, too light to be fitted with an Argos satellite tag, after gathering samples and data and applying bands, Wednesday, April 28, 2021, in Cheverly, Md. The American robin is an iconic songbird in North America, its bright chirp a harbinger of spring. Yet its migratory habits remain a bit mysterious to scientists. (Photo by Carolyn Kaster/AP Photo)
