roller
roller, any of about 12 species of Old World birds constituting the family Coraciidae (order Coraciiformes), named for the dives and somersaults they perform during the display flights in courtship. The family is sometimes considered to include the ground rollers and cuckoo rollers. Rollers inhabit warm regions from Europe and Africa to Australia.
Ranging in length from 25 to 32 cm (10 to 13 inches), rollers look like stocky, short-legged jays and are predominately blue or violet in colour. They gather in noisy flocks to feed on locusts, flying ants, and lizards. Most nest in tree holes; some burrow in termite nests.
The 30-centimetre- (12-inch-) long common roller (Coracias garrulus), found from southern Europe to western Asia, has vivid blue wings with black borders. See also cuckoo roller; ground roller.