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 })ecked 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 1<S() represent bird.s 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 

 tightl}' 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 grij)ping the bird's bill, and is 



