142 Summer Studies of Birds and Books CHAP. 



Continent I have counted the number of times this 

 bird will sing his stereotyped song in one minute, and 

 have always found it the same, viz. between six 

 and seven times. Assuming that he begins at 

 daybreak, he should sing it some five thousand times 

 over in one day ; and one fine morning last June I 

 heard him begin it actually before sunrise. 



I might mention other examples of the same 

 indefatigable activity among our common song-birds, 

 notably in the Skylark, which can hardly be accounted 

 for by the theory of sexual selection ; but I must 

 turn to some other facts bearing on the same 

 question. 



Some birds delight in social gatherings, and in 

 these, where there can be no thought of pairing or 

 nesting, their excitement is expressed either by 

 singing or some other kind of loud utterance. It is 

 not often what may be called the true song of the 

 bird, but it is certainly a vocal effort of the same 

 kind, and deserves to be considered under the same 

 head. These social gatherings will take place even 

 in the breeding season ; generally in the evenings 

 after work is over, and when recreation is possible 

 before sunset and roosting. Last June I used to 

 watch and listen at a certain large osier-bed, in 

 which a rare and interesting bird had then taken up 

 its abode ; and every evening the other birds seemed 

 to be quite put to silence by the incessant singing, 



