SPRING 



the green woodpecker, at any rate, sometimes bores his 

 nesting-shaft in a perfectly sound oak. In a typical nest, 

 there is a horizontal tunnel about three inches wide and 

 five long, which then turns downwards for about eighteen 

 inches, and widens into an oval hollow. The excavation 



of this gallery is achieved 

 by the power of a beak and 

 body framed for similar 

 though less exacting feats 

 of wood -hewing in the 

 pursuit of beetles and 

 grubs. The bill of the 

 woodpecker is shaped like 

 the sharp end of an anvil, 

 and is set in a head and 

 neck of strength well suf- 

 ficient to wield it. The 

 bird grasps the bough with 

 its ' zygodactyle ' feet, in 

 which one pair of toes 

 turns forward and one 

 backward, and props itself 

 with the stout quills of its 

 tail. It lifts its bill like a 

 mattock, dashes it into the wood, and repeats the blow with 

 the whole force of muscle working on a fulcrum until the 

 white shreds drift one after another down the wind. The 

 opening of the hole is beautifully circular, and the perpen- 

 dicular shaft expands evenly into the bottle-shaped chamber 

 where the eggs lie on a few fragments of wood. The wood- 

 peckers are hole-hewers pure and simple, and make no nest. 

 The two smaller spotted species work in the same way, on 

 a smaller scale. They more often drive their galleries in a 



GREAT GREEN WOODPECKER 



