4 o 



and at the same time so prolific that they have as many as ten 

 eggs in their nest. 



The process of hatching of such an unusual clutch for a raptorial 

 bird is abnormal. We stand by the side of such a nest, which lies 

 on the open mountain, generally in the neighbourhood of moist 

 ground. In the nest lie four half-grown young of the size of a 

 hazel grouse, with well developed wings, which in a fortnight's 

 time will be ready to do service ; in addition the nest contains 

 two young ones, which are considerably smaller, and still half 

 down-clad ; lastly three ditto, which are just hatched, and lie 

 half buried under their bigger brothers and sisters. Under these 

 nine young ones we shall finally find an egg, which is perhaps 

 only half incubated, or nearly ready to hatch. These many 

 stages among the young arise from the fact that an interval of 

 several days may often elapse between the laying of one or a pair 

 of eggs and the next ; so soon as the first young ones have burst 

 the egg shell, the parents are obliged to seek food for them, and 

 the incubation of the remaining eggs is thus given up, altogether 

 or in part, to the elder brothers and sisters. In the incubation of 

 the last egg at any rate the parents take hardly any part. 



Whilst the hen is sitting, the somewhat smaller and nearly 

 snow-white old cock bird sits on guard in the vicinity of the nest, 

 and warns his mate by a strange shriek, if a hunter approaches ; 

 both then circle about him with their peculiar slow wing-strokes, 

 and swoop impetuously straight down upon his dog, which may 

 easily be wounded thereby. The hen however in general takes 

 the affair more calmly ; she is more wary than the male, and 

 fatter, since she is always fed by him. Around the nest lies a 

 rich supply of Lemmings and Rype-chicks, whole or dismem- 

 bered, and always in larger quantities than the young are capable 

 of consuming. 



This successive development of the young may be traced in 

 ordinary years also, in other raptorial birds as well, but is most 

 perceptible during these prolific years, since the clutch of eggs 

 is often, e.g., with the Rough-legged Buzzard, or with the Hawk- 

 Owl (Surnia funerta), increased beyond the normal number. 



