74 RIVERBY 



The yellowbird becomes active and conspicuous 

 after the other birds have nearly all withdrawn from 

 the stage and become silent, their broods reared and 

 flown. August is his month, his festive season. 

 It is his turn now. The thistles are ripening their 

 seeds, and his nest is undisturbed by jay-bird or 

 crow. He is the first bird I hear in the morning, 

 circling and swinging through the air in that pecul- 

 iar undulating flight, and calling out on the down- 

 ward curve of each stroke, " Here we go, here we 

 go ! " Every hour in the day he indulges in his 

 circling, billowy flight. It is a part of his musical 

 performance. His course at such times is a deeply 

 undulating line, like the long gentle roll of the sum- 

 mer sea, the distance from crest to crest or from 

 valley to valley being probably thirty feet; this 

 distance is made with but one brief beating of the 

 wings on the downward curve. As he quickly opens 

 them, they give him a strong upward impulse, and 

 he describes the long arc with them closely folded. 

 Thus, falling and recovering, rising and sinking like 

 dolphins in the sea, he courses through the summer 

 air. In marked contrast to this feat is his manner 

 of flying when he indulges in a brief outburst of 

 song in the air. Now he flies level, with broad ex- 

 panded wings nearly as round and as concave as two 

 shells, which beat the air slowly. The song is the 

 chief matter now, and the wings are used only to 

 keep him afloat while delivering it. In the other 

 case, the flight is the main concern, and the voice 

 merely punctuates it. 



