When smaller birds join forces to ward off larger birds, it's called mobbing. This behavior — like calling your family for help — is used by many bird species. The best time to observe mobbing is spring and early summer, when breeding birds are trying to protect their nests and young…

House Finches are evolving rapidly and visibly. In 1941, some captive House Finches from California escaped near NYC. They spread rapidly and are now found across most of the US. We know the finches have evolved, because those that survive differ from their parents. Size is one example…

When a Carolina Wren like this one sings, something remarkable happens. These birds can sing so loudly that you almost have to shout to be heard over their songs! How can a bird like a Carolina Wren – at just 5½ inches long and weighing only as much as four nickels – produce so much sound…

Great Blue Herons nest in colonies, in adjoining trees or with several nests in one tree. But by autumn, the adults and gangly young have left the nests to take up solitary lives, a pattern that is the reverse of many other species. After all the "togetherness" of the nesting colonies, the…

If you see a wild bird with a small metal band around its leg, that means researchers have given the bird a unique ID to keep track of it over the course of its life. You can report the sighting to the Bird Banding Laboratory, a part of the U.S. Geological Survey that studies banded birds…

California's Salton Sea is hot and smelly - and it's also a Mecca for thousands of wintering birds. This inland sea formed when the Colorado River breached floodgates in 1905, forming a lake 45 miles long. The lake has diminished in size and greatly increased in salt concentration, but a…

Common Poorwills don’t sing much when the mercury drops. But they can do something else that is remarkable. As the winter cold deepens, these petite members of the nightjar family can enter a hibernation-like state — and stay like that for hours — or even weeks! Scientists call it torpor…

Woodpeckers, as a group, eat far more ants than most other birds do. Many other vertebrates tend to avoid ants because of their stings or because of the noxious chemicals they contain, like formic acid. But woodpeckers just love them. A Pileated Woodpecker’s diet may be up to 50% ants!

While it’s still winter in many parts of North America, it’s summer in Antarctica. And the King Penguins are singing! Some form breeding colonies that number in the tens of thousands. When many pairs of these colorful birds tip their heads back and sing, it sounds like the world’s largest…

By winter, most warblers have migrated south. But the Yellow-rumped Warbler, which birders affectionately call “butterbutt” is a lesson in adaptation, notes Bryan Pfeiffer, a writer, naturalist, and educator who lives in Vermont. “In winter, when most of their kin are enjoying insects in…