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Earth Matters : Long journey home: Migrant birds and coffee

By Tom Litwin

There’s a vast show of nature that occurs twice a year. If you’re not looking for it, it’s easy to miss. In the spring millions of Neotropical migrant birds, including warblers, thrushes, flycatchers and vireos, flood into New England from Central and South America, and from the Caribbean. In fall they return to their wintering grounds. It’s amazing and seemingly improbable that a warbler weighing one-third of an ounce — the weight of four pennies, composed of bone, feathers and flesh, and feeding on insects, berries and seeds — can routinely accomplish this feat. With a push of their spindly legs, and a flap of their wings, they overcome gravity, flying most of their journeys at night, navigating by stars and the earth’s magnetic fields. This lifestyle is extremely hazardous; weather, natural predators and domestic cats, collisions with buildings, and loss of habitat all take their toll.