12 The Food of Some British Wild Birds. 



It is now generally conceded that the majority of birds are 

 beneficial, and, as elsewhere stated, it is only in connection with a 

 small number that any doubt exists, and it is in connection with 

 these few that we are gradually accumulating reliable data that 

 must prove of considerable value. 



The Food of Nestling Birds. 



It is a well-known fact that nestlings consume during the 

 first few days of their life considerably more than their own weight 

 of food per day, making a daily gain in weight of from twenty to 

 even fifty per cent. During this period feeding commences before 

 sunrise and continues until after sunset. The number of meals 

 taken during this period is very large. Weed* records that in the 

 case of the Chipping Sparrow (Spizella socialis) the total number of 

 visits paid by the parent birds, bringing food, in a day amounted to 

 nearly two hundred. Judd (73) writing of the House Wren (Trog- 

 lodytes aedon) states "that nestlings are fed very frequently, and 

 consume an enormous quantity of food, is well known by a half- 

 day's observation," made by him on June 17th, 1899. He watched 

 the feeding of a brood of three. " The family was found housed in 

 a cavity in a locust tree, and was transferred to a baking-powder 

 can, which was nailed to the trunk of the tree four feet above the 

 ground, a convenient height for observation. The young were 

 about three-fourths grown." The mother wren made 110 visits in 

 four hours and thirty-seven minutes. On the following day similar 

 observations were made, and in three hours and five minutes the 

 young were fed 67 times. Newstead (92) has also given details for 

 the starling as follows : 



During fifty-five consecutive minutes ... 20 visits 



Between 3.50 and 7.55 p.m 25 ,, 



During six and a half hours 79 ,, 



,, six and quarter hours 45 ,, 



Thus, " during a total period of seventeen hours, representing 

 approximately the hours of one day during which food was collected 

 for the young, 169 journeys were made to the nest." This is in all 

 probability much under the average. 



Our knowledge of the nature and amount of food consumed 

 by nestling birds is as yet very meagre. The subject is an impor- 

 tant one, for many birds that in the adult condition feed vpon 

 both animal and vegetable matter, feed their young almost entirely 



* Bull. No. 55, New Hampshire Agric. Exp. fitat., 1898. 



