REGULARITY OF MIGRATION 75 



may subsist on seeds from the previous season. In- 

 sect-feeders of necessity come later, when the 

 weather has moderated to permit the development 

 of plant growth that may shelter and feed insects. 

 In autumn the process is reversed, as the insect- 

 feeders leave for the south early and others linger. 

 The phoebe is one insect-eater that arrives early in 

 spring, but usually its arrival comes shortly after 

 swarms of hardy stone-flies begin to emerge from 

 the larval state in which they have lived through the 

 winter beneath waters of streams, and fly about, or 

 gather on shrubs, trees, and stones near the water, 

 where they furnish a food-supply. Some other 

 birds, as the myrtle warbler, may turn to a vege- 

 tarian diet of dried berries, and so eke out the insect 

 food that they take in summer. A few, as the brown 

 creeper and golden-crowned kinglet, have specialized 

 methods of search for spiders and insects in a state 

 of hibernation. The Carolina wren is a strictly resi- 

 dent form that feeds mainly on animal matter, 

 which it secures in winter by search under fallen 

 leaves and other vegetation, and in crevices about 

 logs, sticks and stones. Cold seems to have little 

 effect upon it; but when heavy snows come and re- 

 main for several weeks, these wrens are in hard 

 straits and many are killed. Those that survive may 

 be seen searching the eaves of buildings, curls of 

 birch bark, or drift left by heavy floods in the limbs 



