Preliminary List of New Jersey Birds. 71 



identifiable. During- the first three days the food consisted of 

 Geometrid larvje and leaf-hoppers, while the grasshoppers, 

 crickets and ants were brought during the last two days. 



It will thus be seen that with these three species of birds 

 the preference of food for the young seems to be Geometrid 

 larvje. This may be partly due to the greater abundance of 

 this food material as well as to the fact that these larvse are 

 about the right size for feeding birds the size of these, and 

 that they are easily prepared for the young. One would ex- 

 pect the wrens to make use of smaller insects than the spar- 

 rows, and the large number of leaf-hoppers fed by them bears 

 this out. 



There was no evidence that any of these birds fed by re- 

 guritation. In the case of the sparrows this was clearly 

 proved, but what might have happened in the case of the 

 wrens can only be surmised. At any rate, the food was uni- 

 formly brought dangling from the bill and was not swallowed 

 before being delivered to the nestlings. This was the case 

 with the very first feedings of both Song Sparrows and 

 House Wrens. 



Intensive studies of this sort are needed for all of our 

 birds. It is not an exhausting sort of work, and pays large 

 returns for the effort and time spent. Generalizations are in 

 order only after a considerable number of nests of each spe- 

 cies are studied, the nests under as different conditions of 

 environment as possible. As one's experience in this work 

 increases accuracy of observation increases. 



PRELIMINARY LIST OF THE BIRDS OF NORTH- 

 ERN PASSAIC COUNTY, NEW JERSEY. 



BY' LOUIS S. KOHLER. BLOOMFIELD, N. J. 



In preparing the following list of birds, which the author 

 has observed in Upper Passaic County, New Jersey, during 

 the past ten years, all of the species have been included to 

 which may be attached no doubt as to their identification or 

 authenticity of record. The territory covered in these obser- 



