154 BAHAMA BIRD-LIFE 



the extent of variation would not be so wide ; but this would 

 be counterbalanced by the fact that any dominant character 

 would be far more likely to be preserved through the forced 

 interbreeding of closely related individuals. This would 

 also hasten the consummation of permanent forms ; the rate 

 of divergence among island-inhabiting species being, there- 

 fore, more rapid than among those of the mainland. 



The absence of terrestrial mammalia on oceanic islands 

 greatly simplifies the problem of existence for species whose 

 habits render them subject to attack from predaceous ani- 

 mals. Species which have become extinct on continental 

 areas, therefore, often continue to exist on oceanic islands 

 which thus play the part of protectors as well as creators of 

 species. The Flamingo, for example, is known in Florida 

 only as an increasingly rare winter visitor to the southern 

 coast ; but in the Bahamas, man appears to be its only ene- 

 my, and, in favorable localities, where it is secure from 

 molestation, this bird continues to exist in large numbers. 



Sooty Tern 



