WILD BIRDS AND EGGS FOUND IN CROW STOMACHS. 4? 



ing season, or from April to July. It is shown further that during this 

 time, on an average, only 1 Crow in 12 eats any young birds or eggs, 

 and even this proportion is much too high, as will be clear from a con- 

 sideration of the fact that 38 of the stomachs containing remains of 

 birds or eggs were those of Crow nestlings, and 25 of these were from 

 9 nests, containing 2 to 5 young each. Since in most cases a single 

 bird is torn in pieces and divided among all the young in a nest, it 

 is evident that the number of birds destroyed has been greatly over- 

 rated. Furthermore, of the 12 stomachs remaining, several belonged 

 to the parents of the above nestlings, so that the number of Crows 

 actually concerned in destroying the young and eggs found in these 

 50 stomachs could hardly have been more than half of 50, and it seems 

 probable that not more than 1 Crow in 20 ever becomes addicted to 

 this sort of stealing. 



It should not be inferred that birds and eggs are specially sought for 

 as food for nestling Crows. The fact that many more young Crows than 

 old ones were collected during the summer months, and that a single 

 bird is -usually divided among the young of a nest, accounts for the 

 larger number of young stomachs containing such food. As a rule, 

 when feathers, eggshells, or other bird remains occurred in the stomach 

 of one nestling in a brood they occurred in all, and in most such cases 

 the remains in the several stomachs were all referable to a single victim, 

 showing that the parents must have divided the food pretty evenly 

 among the young. In several cases two or three members of a family 

 had received food of a totally different character from that furnished 

 the rest, and occasionally one or two stomachs were well filled while 

 the others from the same nest were but partly filled or almost empty, 

 but this was very unusual. Young and rapidly growing Crows need a 

 larger proportion of animal food than adults, and in case such food is 

 scarce it is possible the parents give a larger share to the young, con- 

 tenting themselves with food more easily obtainable. It is noticeable 

 that of the stomachs containing eggs a large majority were from adult 

 Crows, while the remains of fledgelings occurred most frequently in the 

 young. The probable explanation is that old Crows find it difficult to 

 carry eggs without breaking, especially as they are so often attacked 

 and worried by the birds robbed. 



In the case of eggshells the estimated percentage undoubtedly is too 

 small, for the shell commonly formed only 1 or 2 percent of the stomach 

 contents and the soft parts of the egg had disappeared completely. 



The actual quantity of bird remains found in the stomachs is com- 

 paratively small. In very few cases did it form as much as half of the 

 entire stomach contents, though in one or two stomachs it exceeded 

 that proportion. The average for the 50 stomachs was about 18J per 

 cent, or only 1^ percent for the 616 stomachs taken during the season. 

 The average annual amount in the 909 stomachs was almost exactly 1 

 percent. 



