When it’s predictable and wildlife is well adapted, natural flooding can create a biological bonanza. In the Amazon River Basin, which holds one-fifth of the world’s fresh water, annual rains can raise water levels 30 to 40 feet in just days. Forests turn into vast lakes, dotted with trees…

The dawn chorus is that time when, just before sunrise, birds begin to sing. One by one, then all together, their voices join to greet the new day. But which bird sings first? The timing of when a bird joins the chorus seems to depend on how well it can see in low light. So the birds with…

We've all seen sandpipers foraging busily on mudflats or at the ocean's edge. But this Lesser Yellowlegs often carols from the top of a tall conifer in its nesting territory in Alaska. The name "sandpiper" actually comes from the voices of these birds, rather than from their long-billed…

If a bird’s feathers get too dried out, they become brittle. To prevent that from happening, most birds have a gland located above the base of the tail that produces oil. They use their beaks to massage oil from the gland into their feathers to keep them supple. A bird first grips a…

Cypress trees draped with Spanish moss rise from still, dark water. A Barred Owl hoots mightily as an alligator slithers by. It's morning on the bayou. Bayous are found in much of the Southeast from Arkansas to Alabama, across flat land that drains into the Mississippi River. A bayou's…

The tiniest bird in mainland North America: the Calliope Hummingbird - a 3-1/4-inch jewel, weighing in at just a tenth of an ounce. These birds migrate north each spring from Western Mexico. From its perch, a male Calliope Hummingbird surveys its territory. This exquisite bird was named…

In a Western ponderosa pine savanna, tall pines dot an open, grassy landscape. A Western Bluebird flits from a gnarly branch, as this Cassin's Finch belts out a rapid song. The trees here grow singly or in small stands. Upslope, the pines become denser, mixing with firs. Downhill, the…

In spring, a male Sooty Grouse calls from a concealed perch high in a tall conifer. Known as “hooting,” it’s a very low-pitched, five or six-note thunking sound. When a female cackles in response, the male flies down and displays to her by strutting and fanning his tail. Females are…

Among the most welcome features of spring is the renewal of bird song. Can you imagine a spring without the voices of birds? The silence would -- as they say -- be deafening, the absence of their songs like the loss of one of our primary senses. Rachel Carson's 1962 book, Silent Spring…

The Arctic is still wintry when male Snow Buntings return to nesting areas in April. There's a big benefit to arriving early enough to claim a prime nest cavity in a rock face or under boulders, where it will be safer from predators. Nesting in chilly rock cavities means extra care must be…