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and at the same time so prolific that they have as many as ten 
eggs in their nest. 
The process of hatching of suchan unusual clutch for a raptorial 
birdisabnormal. 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 brothersand 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, ¢.g., with the Rough-legged Buzzard, or with the Hawk- 
Owl (Surnia funevea), increased beyond the normal number. 
