THE WORLD'S BIRDS. 175 



some. Tongue very long and extensible, hard 

 and barbed at tip. 



Plumage and Colouration. — Varied in colour, very 

 commonly black and white, sometimes olive-green, 

 or brown, never showing any blue, but very often 

 red or yellow ; no seasonal change, but usually a 

 small difference between the sexes. Young differing 

 little from parents; sex- difference apparent at once. 



Young. — Naked and helpless, fed by parents ; they have 

 bare, swollen skin at the gape, and a warty pad 

 on the hock, as nestlings, and move about in the 

 nest on their hocks. 



Nest. — A hole pecked out in a tree or bank. 



Eggs. — Several, pure glossy white. 



Incubation. — A fortnight, or a little more. 



Courtship. — In the American FUcker {Colaptes aiiratus) 

 the male displays his wings. 



Food. — Chiefly insects, especially wood-borers and 

 shelterers under bark ; berries^ fruit, nuts, and 

 sometimes the sap of trees, are also taken by 

 some. They usually seek food on trees, but some 

 feed on the ground. 



Gait. — On the ground they hop awkwardly, but on 

 the trees they are very active, seldom hopping 

 from bough to bough, but climbing up and round 

 the trunks and large branches ; they descend, if 

 at all, tail first. 



Flight. — Usually somewhat undulating, a few beats 

 of the wings alternating with closure of them for 

 a moment. The feet are carried tucked up in 

 front, and the neck extended. 



Note. — Usually harsh, a cackle or " laugh " ; some- 

 times a piping sound. 



Disposition and Habits. — Shy unless protected, un- 

 sociable as a rule, and often rather quarrelsome. 

 Young birds in some cases will fight violently as 

 soon as fledged. 



