Purple roller
The purple roller ("Coracias naevius"), or rufous-crowned roller, is a medium-sized bird widespread in sub-Saharan Africa. Compared with other rollers its colours are rather dull and its voice rather harsh and grating. Taxonomy and systematics. The purple roller was formally described in 1800 by the French zoologist François Marie Daudin under the binomial name "Coracias naevia". Daudin's description was based on a specimen collected in Senegal. The specific epithet is from Latin "naevius" meaning "spotted" or "marked". A molecular phylogenetic study published in 2018 found that the purple roller was most closely related to  the racket-tailed roller ("Coracias spatulatus"). Two subspecies are recognized: Description. The purple roller is the largest of the rollers, growing to a length of . Adults weigh from with an average weight of . From a distance it appears a dull brownish bird with a white stripe over the eye, a patch of white on the nape and a dark tail. Northern populations tend to have a rufus crown while southern populations have a more olive-green crown. The underparts are purplish-pink streaked with white. The wings are long and rounded while the tail is square-cut. The voice is  a rather grating "ka" or "gaa", repeated rapidly and evenly. Behaviour and ecology. Its preferred habitat is dry thornveld where it spends long periods perched at the top of thorn trees or poles, watching for food items such as insects, spiders, scorpions and small lizards on the ground. It rocks to-and-fro about its longitudinal axis during display flights, calling raucously all the while; starting from above the treetops it plummets towards the ground in rolling flight. It is territorial, and during the breeding season will drive off other rollers, small hawks and crows. This species seems to be  an opportunist breeder, possibly linked to rains, as its breeding season varies from place to place. It nests in natural hollows in trees or uses old woodpecker holes, or in cliffs, riverbanks, pipes or holes in masonry, usually laying three white eggs. The young are fed and incubated by both parents.