The plight of the gravely endangered Spotted Owl illustrates the imperiled status of old-growth forest in the Pacific Northwest. More than 90% of that forest is gone, a percentage that dwarfs even the worldwide loss of tropical forests and wetlands. Spotted Owls rely on those ancient trees…

Helen Trefry, a wildlife biologist in Edmonton, Alberta, wanted to know where the Burrowing Owls in her part of Canada migrated to. How long did it take them to get to their destinations? Where and how did they spend their stopovers? An amateur radio operator from Texas, along with a…

Have you ever wondered if a hummingbird can recognize colors other than red, or if other birds see color? What about this male Scarlet Tanager? Some male birds literally shimmer with brilliant colors-the Wood Duck and peacock, for instance. But color is probably lost on nocturnal birds…

In most birds - if the sexes vary at all in size - the male is larger. But with many hawks and falcons, the pattern is reversed. And female birds of prey are most notably bigger than males among hawk species that hunt agile prey, such as other birds. Perhaps the female Cooper's Hawk's…

What does the Winter Wren hear in a song? It's a long story... What we hear as a blur of sound, the bird hears as a precise sequence of sounds, the visual equivalent of seeing a movie as a series of still pictures. That birds can hear the fine structure of song so acutely allows them to…

Most Barn Swallows migrate south for the winter. But recently, small populations have stayed through the winter, seeking out pockets of flying insects for food. To learn more about this winter surprise, visit BirdWeb.org.

In late September, young Great Horned Owls, now called "juveniles," still roost close together. By mid-October, the juveniles will scatter - or be driven away by the adults - to set up their own territories within a few dozen miles. By age two, they will seek their own mates. Learn about…