222 THE STORY OF THE BIRDS 



"Whip-poor- Will/' ''Who-are-you?" andso forth. 

 Again, some of the American Wood Hewers 

 (Dendroco]aptid^e) assemble and indulge in a 

 chorus of piercing cries, sounding like shrieks of 

 insane laughter. Another extraordinary cry is 

 that of the Bell-Bird of South America, the 

 solemn tolling note of which, uttered at measured 

 intervals, may be heard at a distance of several 

 miles through the forests. During this perform- 

 ance the bird erects the peculiar appendage on 

 the forehead. This consists of a spiral tube, 

 nearly three inches long, jet black in colour, 

 dotted with minute white feathers, and which by 

 communication with the palate can be inflated 

 with air and raised, but when empty it becomes 

 pendulous. Another species, the Friar Bird of 

 Australia, utters a cry which the colonists render 

 as *' More pork," or ^* Four o'clock." The Bustards, 

 too, emit some strange vocal sounds during 

 courtship ; whilst the love notes of certain Grouse 

 are curious, if not actually impressive. Then 

 we have the call of another Australian species 

 so like the cracking of a whip, that the pro- 

 ducer of it has been named the "Coach-whip 

 bird." Lastly, we may mention the musical 

 trills — usually modulations of the call -note — 

 peculiar to certain Sandpipers and Plovers, 



