Lilac-breasted Roller (Coracias caudata)
Aves; Coraciiformes (hornbills, kingfishers, rollers); Coraciidae (rollers); Coracias caudata
Inhabits eastern and southern Africa. Including parts of Ethiopia, Somalia, Kenya, Uganda, Tanzania, Rwanda, Burundi, Congo, Namibia, Angola, Botswana, South Africa, Mozambique, Zimbabwe, and Malawi.
This roller inhabits Acacia savannas with well-spaced trees and brushlands (Fry, 1992). It can be found in open bush country where isolated trees serve as vantage points (Williams, 1978). Also occurs in lightly forested areas including cultivated lands and large gardens (Fry, 1988), although it does not associate closely with human habitation (Fry, 1992).
Considered common, the population is at its greatest density in easy Kenya with as many as 26 birds being counted on a 250 km stretch of road in late April. Abundant in Somalia, frequent to common in Ethiopia, common in the rest of East Africa (Fry, 1988).
The call, in flight and while perched, is a loud guttural "rak, rak". While performing the rolling flight display, this call is rapidly repeated and leads into a harsh, loud "kaaa, kaarsh, kaaaarrsh" call (Fry, 1992).
This species occurs singly or in pairs (Williams, 1978), is very territorial, vocal, and can be aggressive. When feeding, the bird will swoop down from a perch to catch its prey on the ground. After catching the prey it will remain at the kill site while eating or may return to the perch where it will beat the prey against a branch before consuming the carcass.
The "rolling" for which the bird receives its name, is a territorial advertisement. This behavior is usually performed after copulation, against intruders, or to draw attention away from a nest or chickes (Fry, 1988). The behavior involves the bird flying strongly upwards for about 30 feet, then tipping forward and falling with closed wings. The bird plummets, picking up speed, occasionally flapping its wings to gain even more speed. It then levels its flight, rolls to the right and then the left. It will do this five or six times in a matter of seconds (Fry, 1992). The bird may then sweep upward, close its wings and lose speed until it tips forward into a repeat of the roll sequence. Calling is also done while the bird is performing the rolls.
During breeding season a display can be observed between rival males or a courting pair. The two birds will sit on separate perches near each other and call repeatedly. They will flatten their bodies, lower their heads, raise their crown feathers, and lift and spread tail feathers almost vertical. Facing each other, one "attacks" and they both fly up, chest to chest with flailing wings, apparently attempting to claw at each other. At this point they may fall to the ground and struggle for a short time. Then one bird will perform the "rolling" display mentioned above. Some birds have been described as performing a display in which both birds are on the ground neck rubbing and wing opening. The purpose for this display may be different, and is thought possibly to be anting.
In the wild, nests are recorded as being eight to fifteen feet above the ground in a decayed tree branch stump or the top of a dead palm (Fry, 1988). Nests have also been recorded in the sides of termite mounds (Fry, 1992). A pair will modify a nest, but they will not excavate the cavity. But for a few leaf fragments, the nest is unlined (Fry, 1988).
Throughout its range, this roller has been recorded as nesting in all months of the year. The main nesting season is in October and November. Two to four glossy, smooth, pure-white eggs are laid and incubated by both the male and the female. Chicks hatch after an incubation period of 22 to 24 days.
Arthropods and small vertebrates: locusts, grasshoppers, crickets, beetles, moths, butterflies, ants, spiders, scorpions, centipedes, snails, frogs, small reptiles, and birds. Insects include certain noxious forms of grasshoppers and hairy caterpillars.