YOUNG BIRDS IN THE NURSERY 6i 



will be a year hence when, as an adult, it wiU deposit 

 its eggs in the sand after the custom of its ancestors 

 for unnumbered generations. There can be no question 

 of " imitation," or of precept, here. 



Most of what we know of this strange habit we owe 

 to Mr. Butler, and to him we look for the solution of the 

 vexed question — Does the young bury itself at the alarm- 

 note of the parent, or is it buried ? And how is the 

 burying done ? Is the work of excavation carried out by 

 the feet, or is the sand shovelled away by the beak ? 

 Lizards which bury themselves in the sand do so by side- 

 to-side wriggling movements of the body, but this could 

 hardly be the method of the nestling bird. 



Great as has been the vigilance shown by Mr. Butler, 

 he has not yet succeeded in surprising the bird so as to 

 wrest from it these secrets : he has only been able to 

 draw inferences from its behaviour, and to search in the 

 region marked down as the probable area containing the 

 hidden treasure. Quite recently he got a step further 

 when he succeeded in detecting the fact that the eggs 

 were periodically watered and the method of watering ; 

 presently, no doubt, he will witness the burying of the 

 eggs at any rate, which must often be repeated, since 

 they are uncovered and incubated at night. 



The conduct which we have just reviewed, of adults 

 and nestlings in moments of great danger, is undoubtedly 

 instinctive, and we may take it that such instinctive 

 responses are kept alive for the benefit of the race by the 

 elimination of all nestlings where they tend to fall below 

 the safety limit. That selection has played some such 

 part is seen from the fact that the fear of man is not 

 included in the list of responses necessary to salvation 

 in regions where birds have never encountered man. 



