How do Black-capped Chickadees manage to survive the rigors of winter at high latitudes? For survival, chickadees have three things going for them: they're insulated, they're active, and they have a good memory. Thanks to a half-inch coat of feathers, the Black-capped Chickadee maintains…

Thousands of hummingbirds - including these Ruby-throats - are now in southward migration. Hummingbirds that summer in the western US will arrive in the mountains of southern Arizona. (Ruby-throats take a more easterly route.) Countless hummingbird feeders provide continuous nectar in this…

The male Bufflehead performs his extravagant courtship display often. He swims toward the female, bobbing his head up and down at a speed that makes you fear for his neck. He takes off and flies over her with head held low. Then he lifts his head, raises his bushy crest, and skis back on…

Despite its name, the Northern Waterthrush is really not a thrush: it's a warbler. But unlike most warblers, waterthrushes feed on the ground. They winter in the tropics, where they frequent the edges of ponds and mangrove swamps. Where might you find a Northern Waterthrush? Find out at…

Ornithologists think a glitch in a gene that controls migration in Tropical Kingbirds causes them to fly in exactly the wrong direction. From their Arizona breeding grounds, they head northwest in fall, rather than southeast to their usual wintering haunts in Mexico. Learn more at Cornell…

Not only do Cackling Geese sound different, but they also look different from Canada Geese, and their DNA is different. The Cackling Goose was defined in 2004 as a species separate from the Canada Goose.