WARBLERS. 



49 



Vegetable food. — The vegetable portion is only about 2J percent. 

 Xearly all of this was fruit pulp contained in a single stomach. 

 This, with one or two seeds and a few accidental bits of rubbish, 

 makes up the whole vegetable contingent, which, therefore, may be dis- 

 missed without further comment. 



FOOD OF NESTLINGS. 



Some idea of the amount of insect food eaten by warblers may be 

 obtained by watching the feeding of their young by the parent birds. 

 A nest of the summer warbler containing two young, about a week 

 old when discovered, was watched for six hours distributed over three 

 days. The nest was situated in a prune tree in an orchard, and it is 

 practically certain that all the food for this family was obtained in 

 the orchard. The results of the observation appear in the following 

 table : 



Forenoon. 



Afternoon. 



Date. 



Hour of obser- 

 vation. 



Number 

 of feed- 

 ings. 



Hour of obser- 

 vation. 



Number 

 of feed- 

 ings. 



June 12 





3. 26-4. 26 



21 



June 14 8.21- 9.21 

 June 14 10.34-11.34 

 June 15 8. 00- 9. 00 



31 

 32 

 36 



4.36-5.36 

 1. 11-2. 11 



31 

 30 



In six hours 181 feedings were observed, an average of 30^ per 

 hour. As there were only two young, it follows that each nestling 

 was fed 15 times per hour, or for a day of fourteen hours 210 times. 

 Both parent birds took part in feeding the young, but it was noted 

 that the female visited the nest most frequently. 



SUMMARY. 



From the above facts it is evident that the presence of a few 

 warbler nests in an orchard goes far to safeguard the trees from 

 attacks of insect enemies. The inference is plain that the presence 

 of insectivorous birds should be encouraged by the orchardist by 

 every means in his power. The summer warbler is, if possible, even 

 more completely beneficial in its food habits than the Audubon 

 warbler. Its animal food in relation to man is almost entirely nox- 

 ious or rieufral, and it eats so little vegetable food that its character is 

 of but slight consequence. 



WESTERN YELLOWTHROAT. 



(Geothlypis trichas snbspp.) 



In California the yellowthroat is an inhabitant of marshes and low, 

 bushy places among tules or willows. While it is an insect eater of 

 9379— No. 30—07 £ 



