RUBY-THROATED HUMMINGBIRD 335 



short and clearly cut, either single or double; sometimes they took 

 on a rhythmic form and were repeated over and over, for example, 

 s, s, 2, z, s, s, zzt, the last note emphasized; and often they came 

 in a long series— single, double, and triple notes all intermixed like 

 a telegraph instrument in action. 



It was difficult, owing to their activity among the dense branches, 

 to see the birds clearly, and impossible to count them accurately, but 

 I believe that most, if not all, of them were males, their throats in 

 the dark shadow of the branches appearing black. 



On the 24th there were fewer birds in the tree — the petals were 

 falling to the ground— and on the 25th only two or three remained. 



Jane L. Hine (1894) reports a similar gathering of female birds. 

 She says : "About nine o'clock one spring morning, when lilacs were 

 in bloom, we discovered that the old lilac bush by the well was 

 'swarming' with Hummingbirds — just come; we knew they were 

 not there a few minutes before. There are five large lilacs on our 

 premises and those of a near neighbor. On investigation I found 

 four of these bushes alive, as it were, with Hummers — all females. 

 The fifth bush, a Persian, they did not favor." 



From these observ^ations, and several more in the literature, we 

 may infer that the sexes do not as a rule migrate together, and 

 according to the opinion of many observers the males always precede 

 the females. 



Courtship. — In his courtship display the male rubythroat makes 

 use of his marvelous proficiency in flight as well as of the brilliantly 

 glowing feathers of his throat. As we watch him performing such 

 flights as are described below, swinging back and forth along the 

 arc of a wide circle, we get the impression of a bird upheld by a 

 swaying wire; his swings are so accurate and precise that they sug- 

 gest a geometric figure drawn in the air rather than the flight of a 

 bird. Carl W. Schlag (1930), speaking of the courtship flight, says: 



It is comparable to the strutting actions of various species of birds. It is 

 performed several times daily during the breeding season. While the female 

 is quietly feeding from flower to flower, the male will go through this perform- 

 ance, calculated no doubt to impress her more fully with all his charms. Ris- 

 ing up about eight or ten feet above and five or six to one side of her, he will 

 suddenly swoop down, wings and tail outspread, right at her, passing within a 

 few inches of her, the wings and tail making a terrific buzz for a bird so 

 small. Passing her, he rises to an equal height on the opposite side, and 

 turning comes down again in the same way, describing an inverted arc, with 

 that surprisingly loud buzz just as he gets nearest to her. He keeps up this 

 continuous swooping, as I term it, as long as half a minute, at times; at the 

 conclusion of which he usually flies to some near-by perch and rests. During 

 this performance the female feeds quietly at the same cluster of blossoms, 

 not moving any distance away, and sometimes resting on a flrwer-slalk until 

 he is through. 



