102 JOTTIXGS ABOUT BIRDS. 



third week in April, wlien most other species are 

 overflowing with song. Now the Missel-Thrush 

 begins to pair in the autumn or winter, and sexual 

 instincts inspire the song, these Thrushes congregat- 

 ing for a short period in the former season, when 

 most of the birds begin to pair. It may therefore 

 be laid down as a universal rule, that birds that sing 

 in autumn and winter pair in those seasons. The 

 Hedge Accentor's song is particularly charming 

 about the period of the winter solstice ; the birds 

 pair at this date. Sexual rivalry and song are 

 therefore still seen to be inseparable. Birds, how- 

 ever, do not all begin to nest at the same time, so 

 that song is incessant and prolonged over the 

 entire period covered by the nesting of each par- 

 ticular species. It will also be remarked that single 

 brooded birds are the first to become mute, whilst 

 those that rear two or even a succession of broods 

 remain in voice until their season of reproduction is 

 over. The observant naturalist will also find that 

 the songs of birds lose much of their power and 

 persistency after the laying season is over and the 

 more acute stages of sexual strife are passed. The 

 period of song is also a period of battle and great 

 irritation ; males sing at each other, chase each 

 other, fight fiercely, and often in their excitement 



