How Animals Work. 



at a point well concealed by overhanging plants, the 

 Duckbill digs a long and often very winding tunnel, 

 which generally passes in a slightly upward direction 

 until it opens into the subterranean nest, which is a 

 somewhat oval-shaped chamber, and generally carpeted 

 with a plentiful supply of dry weeds and grasses. There 

 is a second opening in this chamber, which leads to a 

 tunnel that descends and has its opening well beneath 

 the surface of the water, so that the Duckbill, if alarmed, 

 can enter or leave its nest unobserved. The many 

 turns and twists of the upper gallery are probably not 

 altogether intentional, but are rather due to various 

 obstacles such as roots and stones, for no two burrows 

 ever have exactly similar curves and windings. 



The graceful Sand Martin that reaches our shores 

 from distant Africa, a slender-winged messenger carry- 

 ing the promise of the coming of spring, though so 

 small and delicate a bird, is yet a wonderfully expert 

 miner, digging in an incredibly short time a shaft of 

 relatively considerable dimensions in the face of the 

 vertical sand cliffs that it always frequents. Working 

 away with its short, delicate bill and slender feet, the 

 Sand Martin scrapes away at the sand and gradually 

 digs out a more or less cylindrical, slightly upward- 

 sloping burrow, which may extend inwards for a distance 

 of from two to four feet. The end of this burrow is 

 slightly enlarged to form the nesting chamber, in which 

 a soft, loose nest is built of straws, lined with feathers. 

 The indefatigable way in which the birds labour at 

 their task is truly wonderful, and one would think 

 that their little feet and beaks would be worn to shreds 

 in the process. They do not generally begin their 



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