250 BIRD BEHAVIOUR 



frequently opens and shuts its bill without pro- 

 ducing a sound that I can hear, at any rate, but no 

 doubt the hen hears it ; and some of the little 

 Eastern Weaver-Finches known as Nuns or Manni- 

 pais. (Munia), go through all the gestures of singing 

 while emitting scarcely any noise audible to us 

 but a faint mew at the finish. As the hens listen 

 very attentively, they no doubt can hear, and 

 evidently like the music, such as it is, though even 

 to them it cannot sound very loud, judging from 

 their close attention. 



The sense of touch in birds is certainly not 

 facilitated by their structure — generally horny 

 beaks and scalcrcased feet, and feather-covered 

 body ; but it is reasonably acute nevertheless. In 

 Ducks, in which the beak is covered, except at the 

 tip and edges, with skin instead of horn, it is no 

 doubt more acute than in most, and the common 

 Sheldrake has the expanded edges of the beak 

 near the tip so soft that it can fairly be said to 

 have lips, while in the Australian Pink-eyed Duck 

 (Malacorhynchus tnembranaceus) these lips are quite 

 large and hang down like the flews of a hound, 

 so that the beak should have much tactile sensi- 

 bility. 



In Snipe and Woodcock, also, the bill is quite 

 soft at the tip, and these birds, like Ducks, feed by 

 feeling in mud ; but hard-billed waders like Storks 

 also grope in mud with much success, and many 

 of these birds also feel in the mud with their feet, 

 though this, like the scratching action often per- 



