Beaks and Bills 



237 



a moment. The common Black-crowned Night Heron 

 is abundant throughout most of North America, and he 

 fishes in legitimate heron fashion; but his near relative, 

 the Boat-billed Heron, is a more tropical species. In 

 voice, appearance, and structure there is little to choose 

 between the two birds, — except that the latter has a broad, 

 scoop-like beak, — a pelican's fish-trap in miniature, which 

 seems to answer every requirement of this strange-look- 

 ing bird. From the 

 muddiness of the water 

 in the tropical swamps 

 from which I have 

 flushed these birds, it 

 seems probable that much 

 of their food may be 

 lesser fry than fish. 



Pebbles and shells, 

 which shelter so many 

 toothsome morsels along 

 the shallows of our sea- 

 shore, offer sumptuous 

 feasts to birds furnished with beaks adapted to pr\ang 

 and probing, and we find all sorts of sizes and shapes. 

 A collection of bills of various wading-birds would look 

 like a complete set of surgical tools! There is the stilt, 

 whose bill is almost straight; the ibis, with mandibles 

 curved downward to probe the crevices between the 

 pebbles on which he stands; the avocet has a pair of 

 recurved pliers, which search out the worm or snail in 

 the deepest fissures ahead of him. At the slightest touch 



Fig. 179.— Bill of Great Blue Heron. 



