BIRDS 



167 



which has lost the power of flight and lives on the ground. 

 The owl-like appearance is due to slender radiating feathers round 

 the eye. 



Order 5. PIGEONS and SAND-GROUSE (Columbse) 



The description already given of a pigeon (p. 139) will give 

 a good idea of the appearance and structure of the birds of this 

 order. 



Pigeons and Doves are distributed over the entire globe, but 

 the largest number of peculiar genera and species are found in 



the southern land 



masses, especially 

 Australia. 



British species are 

 the Rock- Dove or 

 Blue- Rock (Columba 

 livia}, the Ring- 

 Dove, Wood- Pigeon, 

 or Cushat (C. pal- 

 umbus), the Stock- 

 Dove (C. aznas), and, 

 as a summer visitor, 

 the Turtle - Dove 

 ( Turtur communis). 

 Probably the most 

 striking of exotic 



o 



forms, and the 

 largest members of 

 the group, are the Crowned Pigeons of Australasia (fig. 114). 



Sand-Grouse are essentially desert birds, and are quietly coloured 

 to harmonize with their surroundings. Their head-quarters are 

 Africa and Central Asia, also extending into South-west Europe 

 and into India. Their unusually short legs and toes prevent 

 them from perching, but the wings are long and pointed, con- 

 ferring great powers of flight. The tail is also pointed. Some 

 naturalists place these birds in a special order, and they have 

 affinities with game-birds as well as pigeons, as shown by the 

 structure of their digestive organs and the fact that their young 

 are precocious. 



Fig. 114. Crowned Pigeon (Gonra) 



