BREEDING COLONIES. 
361 
The busy hum and noise of the birds on these rocky 
nesting-places only reach their maximum when the 
young are hatched, and they announce their hunger to 
the world at large,—a hunger, by the way, peculiar to 
themselves in its intensity, and never satiated. As they 
clamour for their dues the whirl of sound is increased by 
new notes, and the unceasing rustle of the parent birds 
flying to and fro on their behalf. These have to work 
very hard to keep up a constant supply of food for their 
greedy youngsters; but, strive as they may, they never 
succeed in silencing the young screamers. 
As soon as the nestlings are able to fly, and even 
earlier with the Guillemots, a new page is opened in the 
life of Rock-birds, as we may collectively call the different 
species: they have so far approached maturity as to be 
ready to exchange their airy home for the bosom of the 
ocean. This change of residence is sudden, and not unat¬ 
tended with danger, as is shown by the anxious shuffling 
of the parent birds to and fro, when the time approaches 
for the youngster to take its first and most important 
flight out into the world,—its real entrance into life. 
With one desperate spring the young Guillemot launches 
itself from the giddy height, where it first saw the light, 
into the sea beneath: if the start miscarries the bird is 
hurried to certain destruction. On this account expe¬ 
rienced old birds take great care that the irrevocable step 
is not taken when the tide is out, and the rocks below are 
exposed to view, but only at high water. Anxiously they 
look after the youngster, hound on its perilous voyage, 
and follow it with the swiftness of an arrow to the billows, 
which, in the case of success, receive the frightened 
nestling in their soft embrace. It soon returns to the 
surface, complaining to its parents, who followed it, of 
3c 
