COEACIAD.^. 55 



sionally rises suddenly to a considerable height, rocking 

 violently to and fro, and descending in a similar manner, 

 with a motion resembling that of a boy's kite when 

 falling to the ground on the guiding force being with- 

 drawn. When on the wing it makes a great noise, 

 rapidly uttering harsh and discordant sounds ; its notes 

 are at times not unlike the sound produced by a broad- 

 bladed knife passing through a tough piece of cork, but 

 are in a louder key. This species seeks much of its food 

 on the ground; but sometimes it watches from some 

 elevated position, and, the moment its prey comes within 

 sight, darts upon it with unerring certainty, its habit in 

 this respect being very like that of the Butcher-bird 

 Shrikes. It is a most useful bird, feeding largely on 

 centipedes, scorpions, tarantulas, and other insects, as 

 well as on small snakes and lizards. 



This Koller is one of the earliest breeders in Damara 

 Land, and makes its nest in the hollows of trees, 

 usually such as have been previously occupied by 

 some Woodpecker : the stems of these trees are mostly 

 veiy tall and straight ; and in consequence of this, and of 

 the smallness of the apertures, the nests are very inac- 

 cessible. I have frequently seen such breeding-places 

 without being able to reach them ; but I believe the eggs 

 are white and two in number, and that both parents 

 assist in their incubation. 



The iris in this species is dark brown, the bill black, 

 the legs and toes greenish brown. 



[Mr. Chapman, who refers to this Roller in his ' Travels iti 

 South Africa/ vol. i. p. 282, and Appendix, p. 386, confirms 



