Seven species have been recorded in Iowa. Order: CuculiformesFamily: Cuculidae  The family Cuculidae includes cuckoos, roadrunners, and anis. These birds are of variable size with slender bodies, long tails, and strong legs. Three species have been recorded in Iowa. Order: CaprimulgiformesFamily: Caprimulgidae  Nightjars are medium-sized nocturnal birds that usually nest on the ground. They have long wings, short legs, and very short bills. Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is cryptically colored to resemble bark or leaves. Three species have been recorded in Iowa. Order: ApodiformesFamily: Apodidae  The swifts are small birds which spend the majority of their lives flying. These birds have very short legs and never settle voluntarily on the ground, perching instead only on vertical surfaces. Many swifts have very long, swept-back wings which resemble a crescent or boomerang. One species has been recorded in Iowa. Order: ApodiformesFamily: Trochilidae  Hummingbirds are small birds capable of hovering in mid-air due to the rapid flapping of their wings. They are the only birds that can fly backwards. Five species have been recorded in Iowa. Order: GruiformesFamily: Rallidae  Rallidae is a large family of small to medium-sized birds which includes the rails, crakes, coots, and gallinules. The most typical family members occupy dense vegetation in damp environments near lakes, swamps, or rivers. In general they are shy and secretive birds, making them difficult to observe. Most species have strong legs and long toes which are well adapted to soft uneven surfaces. They tend to have short, rounded wings and to be weak fliers. Eight species have been recorded in Iowa. Order: GruiformesFamily: Gruidae  Cranes are large, long-legged, and long-necked birds. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back. Most have elaborate and noisy courting displays or "dances". Two species have been recorded in Iowa. Order: CharadriiformesFamily: Recurvirostridae  Recurvirostridae is a family of large wading birds which includes the avocets and stilts. The avocets have long legs and long up-curved bills.