The Birdsong That Was Always There

In 2019, a retired schoolteacher named Margaret Chen joined a birding group in Oregon's Malheur National Wildlife Refuge. On her first morning walk, she heard nothing but a wall of noise — wind, rustling grass, a blur of chirps she couldn't separate. Her guide, a veteran birder named Tom, stopped on the trail and whispered, "Hear that? Sagebrush sparrow. Two short notes, then a trill."…