It’s spring, and a female duck swims across a pond with ducklings in tow. Some of the youngsters might not be her own. Wood Ducks and others may lay some of their eggs in other ducks’ nests — or in the nests of other kinds of ducks, like Common Mergansers and goldeneyes. Biologists call…

When nesting, most birds lay a predictable number of eggs. Bald Eagles: 2. Bluebirds: 4 to 6. Mallards: 10 to 12. But how do they determine when they have laid the right number? To find out, scientists experimented by going to nests and repeatedly removing eggs soon after they were laid…

During the days of mammoths and saber-toothed cats, California Condors thrived over much of the continent. Today, they're one of the most endangered birds in the US. The condor's main survival problem is high mortality due to lead poisoning. Condors eat animal carcasses, often containing…

Summer is a crucial time to keep your backyard birds supplied with water for drinking and bathing. Birdbaths set at different heights serve a great variety of birds. A wide, shallow birdbath that deepens a bit in the center will suit a broad range of birds - including this American Robin…

From a bird's perspective, the Dry Tortugas, a cluster of islands in the Gulf of Mexico, can be a life-saver. Millions of migratory songbirds fly north across the Gulf and Caribbean each spring, headed for North America. If they run into heavy wind and rain blowing down from the continent…

During the day, an American Robin, a member of the thrush family, sings a lovely, familiar song of rich phrases. But as the sun begins to set, robin song takes on a different character. From sunset until dark, a robin adds ethereal whispered notes to its carol, creating a song of…

When a Sage Thrasher, perched on a clump of sagebrush, tips its head back to sing, the notes rush forth. They often sing non-stop for at least two minutes. In stark comparison, the song of this Brewer’s Blackbird lasts barely a second. And the Henslow’s Sparrow values brevity even more…

Many birds drink while standing — dipping their beaks into a pond or birdbath, taking a beakful, and then tossing their heads back to swallow the water. But drinking on the wing suits swallows best. They walk awkwardly on the ground, and their long wings are cumbersome. So it’s far more…

Birds communicate with a fascinating array of instrumental sounds, and nearly all are made with their feathers or bills. The territorial drumming of a woodpecker - like this Black-backed Woodpecker - is one example. American Crows clatter their beaks to make rattling sounds. And the…

The Bee Hummingbird, found only in Cuba, is the smallest bird in the world. An absolute miniature, even among hummingbirds, it measures only two and a quarter inches long. Often mistaken for bees, they weigh less than a dime. The female builds a nest barely an inch across, and lays eggs…