Roller
Roller, a group of 16 species of Old World birds named for their habit of tumbling in the air while in flight. Most are brightly colored. The common roller visits Europe and western Asia in summer, and Africa in winter. It grows to be about 12 inches (30 cm) long. It is blue and green, except for its reddish-brown back.
The common roller is Coracias garrulus of the family Coraciidae.
Rollers are brightly colored birds that tumble in the air while in flight.