GENERAL DISTRIBUTION OF BIRDS 21 



open nest of grass and twigs, nor the Robin leave his plastered 

 house for a Woodpecker's hole. 



To some extent we find that birds have changed their 

 feeding habits to adapt themselves to their changed environ- 

 ment. The Flicker that is now more frequently found in the 

 open, scattered groves than in the denser forests, has a bill 

 and tongue evidently designed to take food from the tree 

 trunks. Through change of habitat or through advanced in- 

 stinct, it has found it easier to pick its quarry from the ground. 

 The Red-headed Woodpecker, enjoying the protection afford- 

 ed by association with man, digs its hole in a telephone pole, 

 and finding a scarcity of insect borers in the fewer trees about 

 its home, has become a modified flycatcher and may be seen 

 darting about after an insect in the air after the manner of a 

 Phoebe. 



