Familiar Studies of Wild Birds 



the old holes of sap suckers are selected as nest- 

 ing sites. Their nests are usually to be de- 

 tected by a bunch of twigs sticking out from 

 behind the bark, where they are situated. 

 Also, if one passes within four or five feet of 

 the tree the female generally slips out, thus 

 disclosing her secret, if it has not already been 

 revealed by the protruding twigs. The twigs 

 forming the foundation of the nest are as large 

 as one would expect so small a bird to be able 

 to lift. The nest lining is composed largely of 

 hair, feathers, fine grasses, particles of bark, 

 with sometimes a little wool and willow down 

 included. In one instance, I found a piece of 

 cast-ofF snake skin. The crested fly-catcher 

 has the habit of regularly placing an old 

 snake skin in its nest, but with the rock 

 wren this cannot be a universal trait, as only in 

 a single instance was this material found. 



These small wrens com-ageously undertake 

 a load that, without knowing of their active, 



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