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…

Teetering and gliding not far above the ground, this Northern Harrier - formerly called a Marsh Hawk - scans the marsh grass for voles. If you return to the marsh at night, the harrier will be gone, and it's a Barn Owl you might see, also hunting voles. Although one's a hawk and the other…

In the Bahamas, in 1974, the Eurasian Collared-Dove escaped from captivity and began to breed in the wild. By the late 1970s, the doves had flown west and colonized southern Florida. As their numbers grew, the doves expanded into rural and suburban areas, moving quickly in a northwesterly…

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…

The Greater Flamingo, an American icon, is as comfortable next to a patio as it is in a tropical lagoon. It is found throughout the Caribbean, in the Galapagos, and from southern Europe across Africa to India. Despite its pencil-thin neck and legs, the flamingo miraculously maintains grace…

Ornithologists think a glitch in a gene that controls migration in Tropical Kingbirds causes them to fly in exactly the wrong direction. From their Arizona breeding grounds, they head northwest in fall, rather than southeast to their usual wintering haunts in Mexico. Learn more at Cornell…

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.

Not only do Cackling Geese sound different, but they also look different from Canada Geese, and their DNA is different. The Cackling Goose was defined in 2004 as a species separate from the Canada Goose.

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…

From atop a thermal, Turkey Vultures in groups of up to 200 sail across the Strait of Juan de Fuca, making landfall near Salt Creek County Park on the Olympic Peninsula. The Olympic Peninsula Audubon Society sponsors a free field trip to witness this autumnal passage. Check out that or…