In the southeast corner of Arizona, the roads are dusty, the mesquites scraggly. But in the middle of it all is a dense grove of trees with lush, green foliage. It’s an oasis of sorts, made possible by what in the Southwest is called a tank – short for stocktank or watering tank. A rickety…

High on the north face of Mauna Kea, a volcanic mountain on Hawaii's Big Island, work is under way to save one of the island's most endangered birds, the Palila. Most Palila live on the west face of Mauna Kea. Palila bred in captivity were released on the north face, to join Palila moved…

These Purple-throated Caribs live on many of the Antillean Islands in the Caribbean. The female’s bill is long and deeply curved. The male’s is shorter and straighter. And this one species of bird has a specialized relationship with two different species of flowering Heliconia plants. When…

Some birds have a remarkable knack for staying out of sight. Often we don’t know they’re nearby, until they sing. But with a little practice, we can learn to identify birds without seeing them. Listen to the songs of the Song Sparrow, the Chipping Sparrow, and the White-throated Sparrow —…

The canopies of the world’s tropical rainforests are green year round. So are many of the birds within them, from parrots and hummingbirds to trogons and jacamars, such as this Rufous-tailed Jacamar. Being green in the tropics helps birds blend in to their surroundings, which is especially…

Exactly where are an owl's ears? Well, the eyes of this Great Gray Owl are set in a broad, dish-shaped face. Ridges of tiny hair-like feathers rim the owl's face, creating "facial disks." Just below the margins of the facial disks, concealed by feathers, are the openings to the owl's ears…

Forest fires have profound effects on birds and other wildlife — for better or worse. Birds such as this Black-backed Woodpecker find a bonanza of insects under burned bark and ample snags in which to carve out nest holes. Woodpecker cavities are often reused by birds like bluebirds. And…

In the mid-20th Century, Dutch scientist Niko Tinbergen studied nesting Herring Gulls. He noticed that newly hatched chicks were fed by their parents only after they pecked at the adults' bills. Tinbergen devised experiments that varied the shape and coloration of the adult's bill. It…

Waterfowl such as this Greater White-fronted Goose have long followed a predictable schedule, flying south in autumn after breeding in the north. But for some birds, climate change may be delaying fall migration. Beginning in 1979, scientists in northern Europe recorded migration dates of…

Willow Flycatchers nest across the northern two-thirds of the U.S. and southernmost Canada. A subspecies, known as the Southwestern Willow Flycatcher, nests in the Southwest, as far east as Texas. The Southwestern Willow Flycatcher was listed as endangered in 1995. It's just one of 300…