Family Coraciidae - Rollers
Coraciidae is a family of Old World birds, which are known as rollers because of the aerial acrobatics some of these birds perform during courtship or territorial flights. The family contains 13 species and is divided into two genera. Rollers resemble crows in size and build, and share the colourful appearance of kingfishers and bee-eaters, blues and pinkish or cinnamon browns predominating. The two inner front toes are connected, but not the outer one.
They are mainly insect eaters, with Eurystomus species taking their prey on the wing, and those of the genus Coracias diving from a perch to catch food items from on the ground, like giant shrikes.
Although living rollers are birds of warm climates in the Old World, fossil records show that rollers were present in North America during the Eocene. They are monogamous and nest in an unlined hole in a tree or in masonry, and lay 2–4 eggs in the tropics, 3–6 at higher latitudes. The eggs, which are white, hatch after 17–20 days, and the young remain in the nest for approximately another 30 days.
The roller family Coraciidae was introduced (as Coracinia) by the French polymath Constantine Samuel Rafinesque in 1815.
It is one of six families in the order Coraciiformes, which also includes the motmots, bee-eaters, todies, ground rollers, and kingfishers. The family gets its scientific name for Latin coracium, "like a raven", and the English name "roller" from the aerial acrobatics some of these birds perform during courtship or territorial flights.