32 



FORM AND HABIT: THE BILL. 



corolla. In the Tooth-billed Hummer {Androdon) both 



being also hooked, and the bird feeds on insects which it 

 captures on the surface of leaves and other places. 



Among the Woodhewers {Dendrocolaptida) of South 

 America there is fully as much variability, which reflects 



equally variable feeding 

 habits. Some species have 

 short, stout, straight bills, 

 others exceedingly long, 

 slender, curved ones. 

 Mergansers, Gannets, An- 

 hingas, and other birds 

 them under water, have 



Fig. IS. — Serrate bill of Merganser, a 

 eating bird. ('/ a natural size.) 



that catch fish by pursuing 



sharply serrate mandibles 

 their slippery prey. 



Some shore birds (Limicolce) use the bill 



which aid them in holding 

 a probe, 



Fig. 19.— Probelike bill of Woodcock, showing extent to which upper mandi- 

 ble can be moved. (% natural size; 



when it may be six inches in length and straight, or 

 curved downward. It has recently been learned that 



Fig. 20.— Eecurved bill of Avocet. ( 2 /s natural size.) 



several of these probing Snipe, notably the Woodcock, 

 have the power of moving the end of the upper mandi- 



