The birds in this order are known as birds-of-prey or raptors. They are found on every continent except Antarctica. Worldwide, they have suffered population decline as prey and habitat are disrupted or destroyed. Human persecution is less serious now than in the past due to protective legislation for many species.
Raptors are easily identified from other birds. Their bodies are compact, strong and well developed. The rounded head is attached to a short, strong neck. Their short bill is hooked and the cutting edges of the upper mandible project over the lower mandible like scissors. The bill is covered by a fleshy cere at the root of the upper mandible. Their feet are short and strong with long, curved talons. The outer toe in some species can be rotated to either the front or the rear. Their large eyes have highly developed vision. Raptors have very good hearing, but the olfactory sense is developed only in some New World vultures.
Most raptors are equipped for capturing prey such as insects, amphibians, reptiles, small birds and small mammals. Some species prefer a vegetarian diet, while other prefer a carrion diet of only decaying, rotting flesh.
Most birds-of-prey have one mate in a year, and some will keep the same mate for several years. All lay small clutches of eggs and their reproduction rate is low. There is a marked division of labor during the breeding cycle, with the male providing food while the female stays near the nest and is responsible for incubating the eggs and tending the young. Following a long incubation, the young hatch with a full covering of down and their eyes open. Raptors nest in cliffs, trees or on the ground and many such places are occupied over long periods of time.
Members of this order are generally diurnal, hunting when they can see. The various species range in weight from 2 ounces up to 20 pounds. They can be found in habitats ranging from deserts to deep tropical forests, from steppes to tundra. This order includes the two largest flying birds; the Andean Condor and the California Condor.
Nearly every raptor species performs some sort of migratory behavior. The longest journeys are made by birds which regularly fly between Siberia and Southern Africa, or between North America and South America. All are strong and powerful fliers.