TROGONS, TOUCANS, AND WOODPECKERS 107 



their young. The toes are placed two in front and two behind, and 

 are furnished with long claws, which serve the purpose of grappling- 

 irons. Finally, the tail-feathers are of a curiously spiny character, 

 and serve as supports when the bird, having firmly fixed itself 

 by its claws, begins its work of excavation. The Woodpeckers are, 

 in short, essentially tree-dwellers, and after a very peculiar fashion, 

 for they spend most of their lives, not in perching on the boughs, but 

 in climbing up and down the trunk. The spiny tail-feathers are 

 developed in proportion to the amount of hammering which must 

 be performed to gain a livelihood. They afford, in short, a very 

 effective leverage during the time that the beak is being used as a 

 ''pick." 



But the peculiarities of the Woodpeckers do not end with these 

 external characters. The tongue for example is of enormous 

 length, and the roots, or supports thereof, are no less excessively 

 developed, so much so that they curve round and over the skull, 

 to be finally stowed away in a channel above the beak. This tongue 

 is used as a trap for the capture of ants and other insects. Thickly 

 covered with a sticky saliva, which has been compared to bird-lime, 

 this wonderful and worm-like organ is suddenly thrust out amid 

 swarms of ants, which are borne back into the mouth, struggling 

 helplessly. This saliva is formed by a pair of enormous glands on 

 -either side of the head. 



In Great Britain three species of Woodpeckers are commonly 

 met with. Of these, the best known perhaps is the Green Wood- 

 pecker (Plate XXIII. fig. 2), also known as the *' Yaffle." The 

 female has black upon the cheeks instead of red. 



The Grey-headed Green Woodpecker (Plate XXIII. fig. i) 

 is a near relative of the species just described, and is common on the 

 Continent of Europe. 



The Lesser Spotted Woodpecker (Plate XXIII. fig. 7) is also 

 a British bird, but, owing to its small size and its partiality 

 for tall trees such as elms and poplars, commonly escapes notice. 

 It is more frequently met with in the southern parts of England, 

 being rather common near London and along the valley of the Thames. 

 In Ireland it is rare. Its near relative, the Great Spotted Woodpecker, 

 is a much larger bird, and is nowhere abundant in Great Britain. 



