298 FIELD, FOREST AND FARM 



dinarily keen sense of hearing, on the other hand, 

 advises the bird of all that is going on in the neigh- 

 borhood. Its ears, large and deep, perceive the mere 

 rustle of a field-mouse in the grass. 



"The prey is seized with two strong claws warmly 

 clothed in feathers clear down to the very nails. 

 Each foot has four toes, of which three ordinarily 

 point forward, and one backward ; but, by a privilege 

 common to nocturnal birds of prey, one of the an- 

 terior toes is movable and can point backward, so 

 that the claw becomes divided into two pairs of 

 equally powerful grippers when the bird wishes to 

 seize, as in a vise, the branch whereon it perches or 

 the victim struggling to escape. 



"A blow of the beak breaks the head of the cap- 

 tured rat. This beak is short and hooked, and the 

 two mandibles have great mobility, which enables 

 them, in striking against each other, to make a rapid 

 clacking, a demonstration by which the bird ex- 

 presses anger or alarm. 



"The mandibles open wide in the act of swallow- 

 ing, revealing a mouth of ample proportions and a 

 throat of excessive width. The prey, which has first 

 been well kneaded by the claws, disappears down this 

 throat, bones and all. Nothing is left of the rat or 

 the mouse, not even the fur. 



"Digestion completed, there remains in the stom- 

 ach a confused mass of skins turned inside out and 

 still wearing their fur, and bones stripped as clean 

 as if they had been scraped with a knife. The bird 

 then proceeds to rid itself of this encumbrance of 



