The Blakiston's Fish-Owl is the largest owl in the world. Compared with North America’s largest familiar owl, the Great Horned, the Blakiston's is six inches taller and nearly three times as heavy. No other owl approaches its prodigious girth. But the Blakiston's Fish-Owl is endangered. It…

Gray-breasted Wood-Wrens sing a duet. Each sings a different phrase, yet the phrases are so closely linked, it sounds like one song. Such singing is called antiphonal song. The pairs use song to stake out and hold breeding territories. Dueting is most typical of birds that live in dense…

This Osprey looks similar to other birds of prey. But the species is truly unique among raptors. For example, the Osprey is the only raptor with oily feathers. And the Osprey’s long, slender, arched wings help it clear the water as it takes flight after catching a fish. The Osprey we see…

Every March sees the annual spring migration of Tree Swallows. Most of these swallows spend the winter along the Caribbean, in Central America, and in the warmest parts of South Texas and California. Some will nest as far north as northern Alaska and Canada. Tree Swallows nest only in…

Hummingbirds' names evoke their exquisite qualities and variety, from sabrewings to woodstars to sunangels-to this Violet Sabre-wing. Central and South America are home to well over 300 species of hummingbirds! Find out more about hummingbird migration -- and what hummingbirds might be…

All winter long, our neighborhood House Finches--like this one--have called to one another with their distinctive, sweet cheeps. And our resident Song Sparrows, with calls that sound like a tiny barking dog. But as the days grow longer in late winter, the lengthening light helps trigger a…

Circling silently above the earth on broad, black wings, vultures need little introduction. We know them as nature's clean-up crew, dining on dead and decaying animals. A unique range of adaptations allows vultures such as this Black Vulture to feast on food that’s off limits for many…

It was only in 1939 that this Altamira Oriole was first found north of the Rio Grande River. Now it happily visits residents on the Texas side of the river, especially where a juicy orange half waits in a backyard feeder. Northerly breeding orioles, like Bullock's in the West and the…

What bird laid the largest eggs ever known? To date, the record holder is the now-extinct Elephant Bird, a relative of the present-day Ostrich and other large, flightless birds, including rheas, cassowaries, and kiwis. Elephant Birds lived on the island of Madagascar. But by perhaps 1000…

The idea of the "swan song" recurs from Aesop to Ovid to Plato to Tennyson. Ovid described it, "There, she poured out her words of grief, tearfully, in faint tones, in harmony with sadness, just as the swan sings once, in dying, its own funeral song." But it's based on a sweet fallacy -…