Bulletin No. 15. 45 



3:15. A few birds began to sing. 



3:30. First one left the trees. 



3:31. Ten have left, and small companies of from three to twenty left 

 every few seconds until 4:05, when the last one departed, accompanied 

 by a young one. 352 were counted leaving. At 3:40, robins, and at 

 3:45, cowbirds were seen to leave the trees. The last company of about 

 a dozen cowbirds was driven out by four old grackles at 4:00. All the 

 birds seemed to be singing up to the last ten minutes before the trees 

 were entirely deserted. The cowbirds, however, were not heard at all 

 until 3:45, when but few grackles remained. Robins were heard shortly 

 after the first grackle began to sing, and were heard as long as any re- 

 mained in the trees. None of the birds went far away at first, but 

 seemed to have business close at hand. All but the youngone were 

 old birds. 



In the evening observations were taken from the roof of Spear Library. 

 The sky was almost clear, the air warm and still. 



6:45. Three grackles arrived from the south, but soon flew away 

 again. They were calling. 



6:55. A straggling flight of from one to ten individuals every few 

 seconds began, and ended at 7:15. The birds came in from the south 

 and east in about equal numbers. There was no large flight at any time, 

 nor any concerted action except in the small companies. Nine-tenths 

 came from low down among the trees, the rest at about roo feet elevation 

 above the tree-tops. These had apparently made a much longer flight 

 than the others and came in even smaller companies or singly. A very 

 small proportion arrived singing, or sang immediately after settling in the 

 tree-tops, but there was little noise at any time. The flight of all was 

 rapid and straightforward, and the tail was not carried in the keel-shape, 

 except by those coming in from the neighboring trees. The last small 

 company arrived at 7:20, as darkness settled down. There were no 

 females and only the one young of the morning in the company. As 

 careful an estimate as could be made placed the number occupying the 

 trees at 500. The earlier arrivals remained in the tree-tops for some 

 time before sinking into the foliage, but the later ones usually disap- 

 peared at once. Until some minutes after the arrival of the last company 

 there were always a few birds to be seen in the tree tops. Before it 

 became too dark to see clearly every bird was out of sight. Settling into 

 the foliage and shifting for position occasioned considerable scolding, 

 until darkness brought quiet. 



Cowbirds began to put in an appearance even earlier than the grackles, 



