6o THE INFANCY OF ANIMALS 



the slightest signs of life, recalling the behaviour of the 

 adult corn-crake. 



The instant response to the alarm-note is unquestionably 

 instinctive, as is shown by the astonishing fact that immedi- 

 ately before hatching, that is to say while still imprisoned 

 within the shell, and before they have seen the light of 

 day, the young birds wiU call vigorously, uttering a plainly 

 audible " cheep, cheep, cheeps If the parents give the 

 alarm-note at this time they secure absolute silence. 



Not the least remarkable of these instances of the 

 behaviour of young birds under the influence of fear is 

 the case of the nestling of the Egyptian plover {Pluvianus 

 egyptianus), which buries itself, or is buried by the parent 

 — it is not clear which — an inch or two under the sand 

 till the danger is overpassed. But in this connection, it 

 is to be noted, the eggs are also buried, and this not as 

 a measure of precaution, but as the normal method of 

 disposal. That this is so is shown by the fact, first 

 demonstrated by Mr. A. L. Butler, the Game-warden of 

 the Sudan, that the area over and around the eggs is 

 kept constantly wet by the parent, water being brought 

 from a neighbouring pool or stream, and regurgitated 

 upon the sand over the eggs. The success of this pecuHar 

 method of lessening, and even abolishing, the danger of 

 detecting the eggs may well have begun in an accident, 

 but it has now become an invariable practice, so that the 

 first act of the young bird's life on wriggling out of the 

 shell is to push its way up out of the grave, so to speak. 



The act of burying seems to have become the instinctive, 

 the natural response in the adult to the stimulus of fear, 

 in regard to both its eggs and young. But it is more 

 than probable that this same instinctive response is as 

 perfect in the nestling at the moment of hatching as it 



