272 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



over the surface of a pond and feed among the twittering swallows — 

 a common habit of theirs — they are apt to be silent. 



When the birds appear, leisurely drifting up from the south, they 

 often fly in great loops. They turn slowly aside from their northerly 

 course, swinging farther and farther around until they are moving 

 for a time toward the south, then, veering gradually, they resume 

 their journey, but soon turn again and make another sweeping curve, 

 each loop carrying them nearer their destination. 



An hour before dark, in the lengthening evenings of early May, 

 we often see a little gathering of New England swifts that have 

 settled on their nesting grounds but are not occupied as yet with 

 breeding activities, flying about in company, high over their chosen 

 chimney, chattering together. The birds may be so high in the air 

 that the sound of their voices barely reaches our ears. These newly 

 arrived birds pay little attention to each other and do not approach 

 near or chase one another as they will in June, yet they keep in a 

 loose flock, sailing and flickering in a somewhat circular path and 

 sometimes coast down from their high elevation, and climb up to it 

 again. Then, as dusk deepens, at about the time the bat appears, they 

 gather around their chimney and drop into it. 



Although swifts, during their spring migration, often collect, before 

 going to roost, in flocks of considerable numbers, they are less con- 

 spicuous at this season than during their impressive gatherings in 

 autumn. These are described under "Fall." 



GowrtsMp. — In June, here in New^ England, the swifts become very 

 noisy. Even from within doors we hear their voices as the birds 

 hurry past not far from our roof. As we listen their chips appear 

 sharper and faster than they did the week before, more clearly enun- 

 ciated, and they run in a long series that seems to grow in intensity 

 as the birds come nearer, reaches a maximum when they pass over- 

 head, and dies away as they rush on. 



When we watch the birds at this season we notice also a difference 

 in their behavior. There is little of the slow, apparently aimless 

 circling of early spring, when, although the birds gather in small 

 companies and follow similar paths in the air, they are seemingly 

 indifferent to one another's presence. 



The breeding season is here. Purpose has come into the swift's 

 brain, and purpose has brought intensity and speed, and concentration 

 on a mate. Now they fly close together, two birds, three birds, some- 

 times four in a little bunch. The length of a swift's body scarcely 

 separates them as they tear along, ripping through space, following 

 the twists and turns of tlie bird in the lead. 



Soon two birds are left alone, the others circling off for a time. 

 Both of these birds are chipping sharply, flying fast, close together, 



