136 THE WORLD'S BIRDS. 



They are fed by the parents, inserting their soft 

 swollen bills into the mouths of these. The first 

 food is a milky secretion from the old birds' crops, 

 which is later exchanged for the ordinary food of 

 the parents softened. 



NEST. Very primitive in structure, an open platform 

 of twigs or grass -stems ; usually placed in a tree 

 or bush, sometimes on the ground or in holes of 

 trees, rocks, or buildings. 



EGGS. One or two ; glossy and unspotted, white, rarely 

 slightly tinted. 



INCUBATION. From two to four weeks. 



COURTSHIP. Very demonstrative, but differing much 

 in different groups ; the throat is usually distended, 

 and the tail often spread, but not the wings. 

 Sailing nuptial flights are indulged in by many 

 species, especially the Turtle-doves. 



FOOD. Mainly vegetable, leaves, buds, grain and 

 fruit ; but worms and small snails, etc., are also 

 eaten. They drink by a continued draught, not 

 in sips. 



GAIT. A walk, graceful enough in the ground-feeders, 

 but an awkward waddle in those which keep mostly 

 to trees. Some of these tree -pigeons hop occasion- 

 ally, and some ground species run quickly. 



FLIGHT. Swift and decided, usually by continued 

 rapid strokes of the half-expanded wings. Some 

 species sail at times, but none seem to soar for 

 any distance, or to fly with slow strokes. The neck 

 and legs are outstretched in flight. 



NOTE. Usually pleasant, a " coo " or purr ; a whistle 

 in some fruit -pigeons, and a boom, almost a roar^ 

 in others. There is a short, dull alarm-note, but 

 except for the love -note they are silent birds. 



DISPOSITION AND HABITS. Pigeons are rather stupid 

 on the whole ; wary when molested, and quarrel- 

 some in a weak sort of way. In fighting, they 



