282 COLOUR IN NATURE 



Markings of Kingfishers 



Blue and green structural colours are admirably- 

 displayed in the family of the kingfishers, which 

 show also a gradual progression of colour. Thus in 

 Ceryle rudis the feathers are dark brown or black, 

 more or less irregularly spotted with white, but with 

 the white showing a distinct tendency to form a 

 transverse band at the tip of the feather. In Ceryle 

 guttata the feathers are regularly cross-barred with 

 dull blackish -brown and white. In Carcinentes 

 melanops in the wing-coverts the covered part of the 

 feather is striped black and white, but the terminal 

 bar of white is replaced by blue. In the tail-quills 

 the under surface is usually black and white and the 

 upper surface blue and black. Where there is partial 

 overlapping of the quills, one side of the vane may 

 be black and white and the other exposed side black 

 and blue. The blue patches occur in positions 

 corresponding to the white ones, but are larger and 

 show a tendency to fuse together. In the case of 

 quill-feathers, the blue is confined to the barbs but 

 the barbules are still present, and their dull colour 

 somewhat diminishes the brilliancy of the blue. On 

 the general contour-feathers, on the other hand, the 

 development of the blue colour is associated with a 

 suppression of the barbules, while the barbs as usual 

 tend to become dilated and polished. 



While in many kingfishers blue and black are the 

 dominant colours, in some the blue is replaced by 

 green. Thus in Halcyon lindsayi a yellow colour is 

 common on various parts of the feathers, and where 



