All birds need to sleep — or at least snooze — sometime during each 24-hour period. And most sleep at night. A bird (such as these Mallard Ducklings) may turn its head around and warm its beak under its shoulder-feathers. Songbirds find a protected perch, sheltered from rain and nighttime…

Some birds, such as the Northern Bobwhite, take their names from their songs or vocalizations: "Bobwhite! Bobwhite!" The Killdeer is another bird named for its song: "Kill-dee, kill-dee, kill-dee." There are others. "Poorwill, poorwill, poorwill" calls this Common Poorwill. This bird is…

Most birds are mostly waterproof. Their feathers, aided by oil from preen glands, keep them pretty watertight. So why do birds avoid flying during rainstorms? It may have more to do with the air than with the water. Rainstorms tend to occur when atmospheric pressure is low. Air in a low…

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…

Many birds – like this Indigo Bunting – can be found in ecotones, the borders between two habitats. Indigo Buntings breed in the ecotone between forest and meadow. They are common at Muscatatuck National Wildlife Refuge in Indiana, where grassland and forest are interspersed to produce…

A flock of shorebirds flying wingtip to wingtip seems to act like a single organism, rolling and twisting in exquisite patterns. Flocks like these use a combination of two organizational patterns. One is a “cluster”: lots of birds flying together in a loose, three-dimensional cloud. The…

This American Kestrel evolved to nest in tree cavities or small caves in cliffs. We humans have made life difficult for kestrels. Development has shrunk the open spaces they need. We’ve cleared away dead trees they rely on for nests and sprayed pesticides that eliminate the insects the…

Superb Fairy-wrens teach their embryonic chicks a secret code. This "incubation call" contains a special note that will later serve as a password. When the chicks have hatched, this password enables the adult birds to identify their babies in the darkness of their domed nest. A species of…

The United States is home to more than 550 National Wildlife Refuges - havens for wildlife, including this Canvasback. But only one refuge can claim the distinction of being international: the Detroit River International Wildlife Refuge. It hosts millions of migratory ducks annually in the…

Some gulls and terns may show a glowing pink color, similar to that of flamingos and spoonbills. This pink color comes from pigments in the birds' food called carotenoids. These gulls and terns are able to convert these naturally occurring pigments to hues that may enhance their success at…