THE SONG AND NOTES OF BIRDS. 103 



warble in the air, and become for the moment 

 utterly oblivious to their own safety actions which 

 are seldom observed after the sexual passions have 

 become less fierce and mating is over. I have 

 watched two rival male Chaffinches singing in 

 concert whilst perched in separate trees ; after a 

 little time spent in this musical contest one has 

 flown into the tree containing its rival ; burst after 

 burst of song has been uttered, and finally the two 

 birds have flown at each other in fury, and the 

 stronger male has compelled the weaker to beat a 

 retreat all this happening whilst a female has sat 

 quietly looking on. I have seen Robins get so 

 excited whilst singing that they have been unable 

 to finish their notes, and the song has ended in 

 perfect screams of defiance. In many cases, especi- 

 ally with this species, such contests lead to a battle 

 in which not unfrequently one of the combatants 

 is killed outright or very severely injured. The 

 persistency with which birds will continue to sing 

 when inspired by love is very remarkable. This 

 very winter I noticed a Missel-Thrush perched in 

 one spot for three hours, singing all the time; 

 Sedge Warblers, for instance, seem to sing all the 

 louder and more defiantly if they are irritated. Is it 



