VOL. VII.] ON INCUBATION. 107 



there being without doubt a tendency for the oldest 

 and strongest to obtain more than its due. 



The condition of affairs prevaihng in the case of the 

 oldest and youngest nestlings, is found only in a lesser 

 degree among the other members of the brood — the 

 older chicks demanding with vigour more than their 

 share of food, and the younger having neither the strength 

 to demand their portion with equal insistence and 

 vigour, nor the bulk to bring themselves into notice 

 when the parent bird is distributing the supplies. 

 Evidently the result of this is that the seniors tend 

 to grow at a greater pace than the juniors, and the 

 disparity in size becomes still more emphasized. 

 Gradually the younger members of the brood are 

 starved, and the larger nestlings, with their greater 

 bulk and strength, tread the smaller under foot, until 

 these unfortunates give up the unequal struggle and 

 perish, doomed, as they were, from the hour when 

 they left the shell. 



A somewhat similar state of affairs prevails in the 

 case of some of the Falconidae. 



The Buzzard is a case in point, the younger members 

 of a family frequently disappearing. The following 

 extracts are illustrative of this. 



Mr. Arthur Brook, writing in the Field of January 

 20th, 1912, says of this species : — 



Should all the eggs be hatched, one of the young birds (always the 

 smallest and youngest) will sometimes disappear. Time and again 

 I have observed this happen. In my opinion the young bird is starved 

 to death by the larger youngsters taking all the food, and when dead 

 is actually devoured by them. I have known this happen in the case 

 of the Sparrow-Hawk. Out of a nest containing six yoiing birds, 

 one^a v^ery young one — disappeared, all except its beak and part of 

 th3 skull. If it were not eaten how came these fragments to be left 

 in the nest ? 



Professor J. H. Salter also writes* of the Buzzard : — 



Incubation'^appears to commence as soon as the first egg is laid. 

 The yoimg are consequently hatched at intervals or one, or perhaps, 

 two days. The nestling which is first hatched is naturally the strongest, 

 and the result is frequently a family tragedy. It appears to be quite 



* Zoologist, 1904, p. 101. 



