Scientific American [unpaywalled]: “It’s springtime in the Northern Hemisphere, and one of nature’s greatest spectacles is unfolding: the migration of billions of birds to their breeding grounds. They’ve spent the winter in balmier locales to the south, getting fat on insects, seeds, fruits and aquatic plants and prey. Now they’re winging their way north to establish territories, find mates and raise their young. In my corner of New England, the migrants have been trickling in—Tree Swallows, Ospreys, Greater Yellowlegs, Chipping Sparrows and Hermit Thrushes, among others. Just the other day I heard my first Louisiana Waterthrush of the season, its song ringing throughout the forest. In a couple of weeks, we’ll hit peak migration, with loads of gorgeous warblers, vireos, thrushes, flycatchers and sandpipers arriving on southerly winds. For those people who enjoy watching birds, this is the most wonderful time of the year. Not only are these birds returning from their winter hiatus, but they are also decked out in their colorful breeding plumage, singing lovely songs, showing off their best courtship moves to prospective mates and building nests for their babies. There’s so much to observe if you know what to look and listen for—and where to find it…”