238 



The Bird 



of such a beak, the oysters and other large bivalves 

 close with a snap, defying these birds to penetrate their 

 living armour. Indeed, more than once a gull or wader 

 has rashly pecked at the sweet flesh, when the two tight- 

 fitting doors have suddenly closed, pinning the bird help- 



FiG. ISO. — Boat-billed Heron. 

 Figs. 179 and ISO represent birds with slightly different feeding habits. 



less and holding it captive despite its struggles, until 

 the rising tide has ended its life. 



But along comes a bird, well named Oyster-catcher, 

 and woe to the mollusks now. It allows them to close 

 tightly upon its bill, the mandibles of which are thin 

 like blades, many years antedating man's oyster-knives. 

 The mollusk is wrenched free by the sturdy bird, car- 

 ried from the water still gripping the bird's bill, and is 



