116 CONTROLLED NATURAL SELECTION 



pression of the utility of the theory is thereby 

 obtained, because it appears necessary to so 

 frequently strain it. Theories are usually 

 substantiated by chosen facts. It is well, 

 therefore, to state that 173 birds have been 

 considered, and only a few have required to 

 be reviewed. 



TABLE I. BIRDS OF PREY 



Falconidae - 



Marsh Harrier . . 

 Hen Harrier . . 

 Montague's Harrier 

 Buzzard .... 

 Golden Eagle . . 

 White-tailed Eagle 

 *Sparrow Hawk . 

 Osprey .... 

 Peregrine Falcon . 

 Merlin .... 

 Kestrel .... 



~, .. f Richardson's Skua 



Stercorarimae \ ~ 



I Common JSkua 



Heron . 



Circus seruginosus 

 C. cyaneus 

 C. cineraceus 

 Buteo vulgaris 

 Aquila chrysartus 

 Haliartus albicilla 

 Accipiter nisus 

 Pandion palisetus 

 Falco peregrinus 

 F. sesalon 



Tinnunculus alaudarius 

 S. crepidatus 

 S. catarrhactes 

 Ardea cinerea 



[* Mimicked by cuckoo, Cuculus canorus.] 



TABLE II. NIGHT BIRDS 



f Barn Owl . . 



Long-eared Owl 



Strigidse I Short-eared Owl 



Tawny Owl . . 



v Little Owl 



Strix flammea 

 Asio otus 

 A. brachyotus 

 Syrnium aluco 

 Athene noctua 



