154 Bird -Lore 



male departed at once, leaving the young to spend the night alone. During this 

 long day of fifteen hours and twenty-five minutes the nestling received food 

 130 times, once every seven minutes on an average. The bill-of-fare included 

 fifty caterpillars, eight beetles, three moths, and one grasshopper while the 

 substance of sixty-eight feedings could not be determined. 



We have said nothing of what the male ate. Surely he required as much as 

 the fledging, undoubtedly more. If he ate only as much as his offspring he was 



CHIPPING SPARROW AND YOUNG, AFTER FEEDING 



instrumental, during a single day, in destroying 260 insects or their larvae, 

 taken almost exclusively from the garden. Such a day's work might be con- 

 sidered extraordinary, but not so. Usually the young number three to five, 

 which means that the parents must double the activity of the one under con- 

 sideration, or the nestlings must go without sufiicient nourishment. The 

 latter is undoubtedly the correct assumption; otherwise, with a brood of five, 

 each parent would be obliged to visit the nest 325 times per day, i. e., once 

 every 2.7 minutes, which is hardly probable. In the case of our Chipping Spar- 

 rows the male provided the fledgling with food, on an average, once every 4.5 

 minutes during the first four hours of the morning, a rate which if maintained 

 throughout the day would have totaled 200 feedings. If this be the maximum 

 (a number which the most diligent little Wood Pewee does not exceed) then 

 it follows that even a family of four young are put on short rations or that one 

 or two are nourished abundantly at the expense of the others, which explains, 

 in part, the discrepancy in size so often observed among members of the same 

 brood. 



It is quite evident that a nest of five will keep the two adults busy. How 

 many insects then should a family of seven consume per day? We can answer 

 this only by making a number of assumptions, each or all of which may be far 

 from the truth. Let us assume (i) that each of the old birds will eat as much as 



