158 ANIMAL LIFE IN DESERTS 



Falconers say that as a general rule trained 

 Peregrines and Shahins cannot capture these birds 

 except by chance, and that the ordinary desert 

 Falcons, the Sakers and Laggers, are less swift than 

 the Peregrines. It would seem, then, that the 

 Coursers and Sandgrouse are protected from Falcons 

 more by speed than colour. I know of no other 

 predaceous animals which hunt by day and which 

 may be supposed to chase Sandgrouse or Courser. 



The real enemies of these birds are probably cats 

 and foxes and possibly jackals ; these aU hunt by 

 night and by scent, so that the colour of the bird 

 motionless in a dim light can hardly have a protective 

 value to it. 



Now, let us consider the predaceous birds and 

 animals — first those of diurnal and then those 

 of nocturnal habits. The supporter of protective 

 coloration supposes that they are coloured like the 

 desert in order that they may more successfully 

 stalk and seize their prey, that is to say that their 

 colour effaces them. This ingenious explanation 

 fails to cover the facts. The Merlin is fairly famihar 

 to many of us as a small hawk, widely distributed in 

 Europe and Northern Asia. It feeds largely on small 

 birds and hunts on the wing ; any colour and pattern 

 which is to prevent the small birds from seeing it 

 should therefore be on the imder side of the bird. 

 As a matter of fact, the ordinary western form of 

 Merlin {Falco columharius regulus\ which does not 

 breed in deserts, winters, among other places, in the 

 deserts of Algeria, Tunisia and Egypt. Farther 

 East, however, there is a race {Falco columbarius 



