158 THE BIOLOGY OF BIRDS 



Another association includes the birds of the woods and 

 forests, such as the capercailzie which became extinct in 

 Scotland about 1762 (and long before that in England and 

 Wales), but was re-introduced from Sweden in 1837 and 

 has now a firm footing in many parts of Scotland. Its 

 relative the blackcock may also be included as a woodland 

 bird. More distinctive is the tree-creeper, already men- 

 tioned, which runs up the bark like a mouse. There is 

 safety in its very rapid movements and inconspicuous 

 coloration. Its slender curved bill is admirably adapted 

 for picking small insects and spiders out of the crevices ; 

 the long curved claws grip the bark in the jerky spiral ascent ; 

 the stiff-pointed tail-feathers brace the bird up when it 

 pauses to peck. As in every other case, we have to deal 

 with a bundle of adaptations. The woodpecker is another 

 typical member of the association. 



The largest group is that of hedgerow and meadow birds. 

 We think of such familiar examples as hedge-sparrow, 

 blackbird, wren, and shrike in the hedgerow ; or lark, 

 meadow-pipit, corn-bunting, and whin-chat in the meadow. 

 But it would not be difficult to multiply these by ten, if 

 one does not take the words hedgerow and meadow too 

 literally. 



Another association is that of river and estuarine birds. 

 We think of the dabchick and the water- wagtail, the coot and 

 the water-hen, the kingfisher and the water-rail. On the 

 lower reaches of the river, or on the flat shores of the estuary, 

 there are gulls, terns, dunlins, redshanks, and more besides. 



§ 9. Protective Coloration 



The flying bird readily catches the eye as an opaque 

 object in the air, but against their natural backgrounds 

 most birds are inconspicuous. In ordinary cases there are 

 only isolated points in the plumage that reflect the light 

 brilliantly, and when there is great splendour, as in the 

 peacock's tail, or in the cockatoo's plumage, or in king- 

 fishers and humming-birds, there is usually some counter- 



