■546 



FROJI NORTH POLE TO EQUATOR. 



entirely, but the bitter war of species against species gives place gradu- 

 ally to conditions which are at least endurable. The birds become 

 accustomed to each other, and make use of the capabilities of their 

 adversaries as far as may be. It may even happen, indeed, that 



Fig. 80.— Rooks and their Nests. 



those who have been plundered follow those who have robbed them 

 when the latter find it necessary to change their brooding-places. 



The spectacle of a mixed heronry is fascinating in the highest 

 degree. " There is hardly anything ", writes Baldamus, " more 

 ^-aried, more attractive, more beautiful, than these Hungarian 

 marshes with their bird-life, which is remarkable both for the 



