How Birds Are Classified

Birds form the class Aves of the phylum Chordata. There are two subclasses: Archaeornithes, which consists entirely of extinct birds (including the archaeopteryx); and Neornithes, which includes three superorders:

I. Odontognathae. Extinct birds that had teeth. Examples are the ichthyornis and hesperornis.

II. Impennes. This consists of only one living order, Sphenisciformes, or penguins.

III. Neognathae. There are either 28 or 29 orders to this superorder (depending on how 12 is classified). They are:

1. Struthioniformes, ostriches.

2. Rheiformes, rheas.

3. Casuariiformes, cassowaries and emus.

4. Dinornithiformes, the moas; extinct.

5. Apterygiformes, the kiwis.

6. Tinamiformes, primitive fliers. (All the birds previously listed are flightless.) An example is the tinamou.

7. Gaviiformes, freshwater diving birds with pointed bills and webbed feet.

8. Colymbiformes, or Podicipidiformes, freshwater diving birds with pointed bills and lobed feet.

9. Procellariiformes, seabirds that are strong fliers with webbed feet.

10. Pelecaniformes, pelicans and their relatives.

11. Ciconiiformes, wading birds with long necks and long legs.

11A. Phoenicopteriformes, flamingos. They are sometimes grouped with the Ciconiiformes, sometimes as a separate order.

12. Anseriformes, waterfowl.

13. Falconiformes, day-flying birds of prey.

14. Galliformes, domestic and wild fowl.

15. Gruiformes, long-legged birds with bare foreheads.

16. Diatrymiformes, large, extinct birds; found only as fossils.

17. Charadriiformes, shorebirds; live on or near water; few other characteristics in common.

18. Columbiformes, pigeons and their relatives.

19. Psittaciformes, parrots.

20. Cuculiformes, cuckoos and their relatives.

21. Strigiformes, owls.

22. Caprimulgiformes, birds with small bills but large mouths; feed on insects in flight.

23. Apodiformes (formerly Micropodiformes), swifts and hummingbirds.

24. Coliiformes, African birds that creep among tree twigs where they feed on fruit. The common name is mousebird.

25. Trogoniformes, birds with long tail coverts and beautiful plumage; live in forests.

26. Coraciiformes, brightly colored birds with short legs and long bills.

27. Piciformes, woodpeckers and their relatives.

28. Passeriformes, perching birds.

Ratites (RAT yts) are a large group of flightless birds. This group includes the ostrich, the emu, rheas, cassowaries, and kiwis. Like penguins, ratites are flightless. However, they are not closely related to penguins.

Like penguins and other birds, ratites have feathers. Most kinds of ratites are bigger than most kinds of penguins. And while penguins are great swimmers, no ratites can swim. Instead, ratites get around by walking and running. In fact, the ostrich can run faster than any other kind of bird.

As you can probably guess, swimming birds are birds that swim. Swans are swimming birds. So are ducks and geese. Puffins, storm-petrels, and loons are also swimming birds.

Some swimming birds, such as swans, ducks, and geese, are closely related. Others are not so closely related. Still, all swimming birds are alike in that they spend most of their lives near water.

Like all birds, swimming birds have feathers. And they have bills and feet. But the feathers, feet, and bills of swimming birds have special features for life in and near the water. Swans, for example, have waterproof feathers and webbed feet for swimming. They have flat bills for eating water plants.

Galliforms (GAL uh fawrmz) are the birds that scientists have grouped into a scientific order called Galliformes (gal uh FAWR meez). Like most birds, galliforms have feathers and wings. Unlike many other birds, however, galliforms live on the ground.

Quail (kwayl) are small galliforms. There are about 45 species, or kinds, of quail. Most adult quail are only 8 to 12 inches (20 to 30 centimeters) long. The heaviest quail weigh only about 8 ounces (230 grams)—the weight of a cup of yogurt!

Like other galliforms, quail live on the ground and build their nests there. They hide these nests behind tall grass. Quail are able to fly. They cannot fly far, though. When quail do fly, it is usually only for a short distance and to get away from a predator, such as a fox.

Other well-known galliforms are chickens, turkeys, and pheasants (FEHZ uhntz). Because all these birds are often hunted for sport and for their meat, they are also known as game birds.

Quail live throughout the world. They live on grasslands and in other open habitats on all continents except Antarctica.

All galliforms, including quail, are widespread. The partridge (PAHR trihj) lives in Europe, Asia, Africa, and Australia. Grouse (grous) live in North America, Europe, and Asia. There are even a few species of galliform that live far north within the Arctic Circle.

Because many species of galliform are hunted for sport, these birds have also been introduced into areas in which they did not originally live. For example, at one time the ring-necked pheasant lived only in parts of Asia. In the late 1800’s, people brought this pheasant to Europe and North America. In many of the areas where it was introduced, the ring-necked pheasant still survives.

Some male pheasants have bright, showy feathers. Male turkeys spread out their fans. Male ruffed grouse also open up their fans. These are examples of male bird behaviors called displays. Another galliform with a strange display is the male Bulwer’s pheasant. This bird has bright blue areas of skin on its head, called wattles (WOT uhzl). He enlarges these wattles during a mating display.

While it seems as if these male birds are just showing off, there is a purpose behind their display behaviors. Male birds use them to attract female birds. The males with the best displays are usually the healthiest and most fit.

Female galliforms are attracted to fit males of their species because these males are often more capable of helping to raise young. In addition to being better able to raise young, healthy parents tend to produce healthy young. That is because, as with other animals, the offspring of birds share the hereditary traits of their parents.