EASTERN ROBIN 35 



pace with the sun, but beginning far in advance of its light, as it 

 moves across the continent from the Atlantic to the Pacific. 



As July advances, the morning chorus, which the robins have been 

 performing since early in April as an almost formal observance in 

 the hush before dawn, begins to fade out and wane. By the middle 

 of the month, if we listen at our window as the sun approaches the 

 horizon, and its light increases to the degree when robins are accus- 

 tomed to awake and sing, there is silence — or at most a single robin 

 singing alone, far away; we hear only the birds of night, the killdeer 

 and the nighthawk. But after half an hour of waiting, as day comes 

 nearer, when the gray of night no longer shuts in our vision, and we 

 look out on a green world again, we may see a robin shoot swiftly 

 past our window, then another, and then others, flying to the trees 

 near the house. Soon we hear them singing, rather freely to be 

 sure, but not in the organized chorus of early summer. 



This delay in the morning singing is doubtless due to the fact that 

 at this season the male robins do not spend the night near their nesting 

 sites but at a roost to which they escort the young birds of the first 

 brood. If we watch the fading sky at evening, we may see the robins 

 of the neighborhood start off toward the roost, trailing along in loose 

 order, after calling restlessly in the trees for a while, and perhaps 

 singing a little. The evening chorus, too, is over for the season. 



Horace W. Wright (1912) and Francis H. Allen (1913) have pub- 

 lished the results of careful studies of "The Morning Awakening" to 

 which the reader is referred. 



Robins sing freely from early in April to the close of the nesting 

 season late in July. In August and September they sing very infre- 

 quently, but later in the autumn and even in winter we hear sporadic 

 songs from the wandering flocks of late migrants and wintering birds. 



Albert R. Brand (1938) gives the approximate mean vibration fre- 

 quency of the robin's song as 2,800, a little lower than that of the 

 red-eyed vireo, 3,600, and of the scarlet tanager, 2,925, birds whose 

 songs resemble somewhat the song of the robin. However, the highest 

 recorded note of the redeye is much higher, 5,850, than the highest 

 note of the robin, 3,300. 



The robin has a variety of notes in addition to his familiar song. 

 Some of these, although as well known perhaps as the song, are not 

 easily suggested by syllables. Many observers have their own set 

 of renderings in phrases and syllables, which represent to them the 

 various utterances of the robin, but these renderings, even for the 

 same note, differ from one another in marked degree. Also, a feature 

 that adds to the difficulty in describing robins' notes is that they 

 resemble one another sometimes rather closely, so that it is hard to 



