Scientists have long thought that new species took a very long time to emerge. This thinking has now changed dramatically. On an island in the Galápagos, researchers Rosemary and Peter Grant discovered that a hybrid union of two distinct species of finch produced descendants different from…

The White-crowned Sparrow pours out its song over and over on spring and summer days-and even on moonlit nights-often up to 15 times a minute. Now here's a curious thing: Just as people in different regions may have different dialects, White-crowns have different songs, according to where…

When glaciers pushed south into what is now the U.S. around 20,000 years ago, they scraped off the soil layer and spelled the end of native earthworms except in the southern states. So the earthworm plucked by the robin in the park or on your lawn is probably a relatively new arrival, most…

A clean feeder is a life-and-death matter to some birds. To protect the birds at your feeder, clean it at least once a week, more often if necessary. Rake the ground underneath, too. Pine Siskins are especially prone to salmonellosis, a bacterial disease. You can learn more about feeding…

People often say that spring “bursts” forth. But this seasonal change isn’t like flipping a switch. It’s more like a series of waves breaking slowly. Robins and bluebirds return north in March. During April, more songbirds migrate north from the tropics, adding to spring’s growing chorus…

At sunset, the male American Woodcock - a plump, robin-sized bird - walks slowly on short legs from the cover of the forest to a nearby clearing. After a few sharp calls, the woodcock takes flight. As it spirals upward, slim, stiff feathers at its wingtips create a curious twittering. At…

Birds are often admired for their ability to fly. But braking just in time to avoid a crash landing is amazing by itself. How does a robin go from full-out flight to a dead stop at a tree? If we could watch in slow motion, we’d see it raising the angle of its wings higher and higher from…

Weighing about as much as four paperclips, Bushtits are smaller than many hummingbirds. And they take full advantage of their diminutive size. While larger insect-eaters forage on the upper surfaces of leaves, Bushtits hang beneath them, plucking all the tiny insects and spiders hiding out…

The glorious song of the male Sage Thrasher rings out every spring from tracts of sagebrush throughout the West. Sagebrush was once widespread in the Great Basin region, and so were the thrashers. But huge areas of sagebrush were turned into alfalfa and potato farms, and the songs of the…

For such a small owl, the Northern Saw-whet has a lot to say. And a lot of ways to say it. Males weigh about as much as an American Robin. And they send out at least 11 different calls, including “toot-toot-toot” advertising calls, from late January through May. The rate of calling is…