BIRDS IN THE CALENDAR 



answer, without any thought of irreverence, 

 is " God knows ! " It is most certain that we, 

 at any rate, do not. So far from explaining 

 how it was that rooks came to build their 

 nests in company, we cannot even guess how 

 the majority of birds came to build nests at 

 all, instead of remaining satisfied with the 

 simpler plan of laying their eggs in the 

 ground that is still good enough for the 

 petrels, penguins, kingfishers, and many 

 other kinds. Protection of the eggs from rain, 

 frost, and natural enemies suggests itself as 

 the object of the nest, but the last only would 

 to some extent be furthered by the gregarious 

 habit, and even so we have no clue as to why 

 it should be any more necessary for rooks 

 than for crows. To quote, as some writers do, 

 the numerical superiority of rooks over ravens 

 as evidence of the benefits of communal 

 nesting is to ignore the long hostility of 

 shepherds towards the latter birds on which 

 centuries of persecution have told irreparably. 

 Rooks, on the other hand, though also 

 regarded in some parts of these islands as 

 suspects, have never been harassed to the 

 same extent ; and if anything in the nature 

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