WESTERN BIRDS YeUow-Throats 



peeks from out his hiding place in some dense tangle, 

 the thought of a highway robber whose eyes are con- 

 cealed with a black domino, flashes through your mind, 

 only to be as quickly cast aside when you behold the 

 gay breast and the friendly attitude of the highwayman. 

 Surely, though he wear a mask no holdup was intended, 

 unless, indeed, it be a holdup of insect life, and accord- 

 ing to all observers these pests had best beware for few 

 of them escape the bright eyes of this little warbler. 



Forbush tells us of a pair of these Northern Yellow- 

 throats that were watched by Mr. Mosher as they fed 

 on plant lice from birches in Massachusetts, that were 

 seen to eat 89 insects in one minute. Continuing eating 

 at this rate for forty minutes it was estimated that over 

 7,000 plant lice were consumed. The small size and soft 

 bodies of the insects which made them easily compressed 

 in the stomach, and the rapid digestion of the birds 

 made it possible for them to eat this amount. These 

 Yellow-throats were seen to come daily to these birches 

 and feed upon the plant lice. Making a conservative 

 estimate of the amount eaten, Mr. Forbush believes 

 10,500 aphids were consumed daily, or 73,500 a week. 

 Surely, this sort of highway robbing has our most hearty 

 approval. 



Besides plant aphids, the Yellow-throat is fond of 

 many injurious insects. Leaf hoppers, which occur in 

 some pastures to the number of a million to an acre, and 

 eat as much grass as one cow, are preyed upon by these 

 Warblers. In the orchards they hunt out the canker- 

 worms for their young, as well as caterpillars of the 

 gipsy moth, one bird having eaten 52 of these pests in a 

 few minutes. Beetles, flies, the western cucumber beetle, 

 and the black olive scale are also relished by these 

 birds. 



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