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TEXT-BOOK OF ZOOLOGY 



and fir woods. It also industriously searches for all kinds of insects in 

 the cracks and furrows of the bark, and when they are ripe feeds on the 

 seeds of fir-cones. Let us now examine how the bird is adapted for 

 obtaining food of this kind, and more especially insects living under the 

 bark or in the wood of trees. 



1. Its feet are specially adapted for holding on to the trunks of 



GREAT SPOTTED WOODPECKER AND NEST. 

 (One-fifth natural size.) 



trees. The toes are provided with curved, 



sharply-pointed claws, which can hook 



themselves into the smallest inequalities 



of the bark. Two of the toes are directed 



forwards and two others backwards 



(climbing or scansorial feet). The former serve to suspend the body; the 



latter support it and prevent it from slipping down. Three of the toes being 



very long, the bird is enabled to embrace a large surface with its feet. 



2. Owing to the shortness of the leg (tarso-metatarsus) and the 

 narrowness of the sternal keel, the woodpecker sits with its body pressed 

 close to the trunk. This renders its seat safer, since the centre of gravity 

 of the body comes to lie above 



3. The tail, the feathers of which terminate in stiff-pointed ends, 

 which are propped against the ridges and rugosities of the bark. The 



