166 The Wilson Bulletin — No. 89 



flocks were seen first as they came over the ridge of the hills. 

 I kept on going northeastward thinking that each hill con- 

 cealed the ravines where the flocks formed. Each time how- 

 ever I was disappointed and was forced to go still farther on, 

 until at last about dark I saw a few flocks fly out of a ravine 

 about one and one-half miles from Newton St. This how-- 

 ever did not prove to be the source of the supply for the next 

 day about noon this ravine was deserted, proving that the 

 flocks stopped only for a brief rest. On the same evening (the 

 30th.) we were surprised to find many kingbirds flying over 

 the same route. The kingbirds, however, flew somewhat earl- 

 ier than the Robins, although part of the time the flight was a 

 mixed one. The last of the flight consisted entirely of robins, 

 which flew until it became dark. 



The Robins flew faster and with more rapid wingbeats than 

 the Kingbirds. The observations of this evening made clear 

 that the flocks gathered over a very large territory, and were 

 formed by additions from the many ravines east of town. A 

 word of explanation might be made as to the use of the term 

 " flocks " in this connection. At the best time of the flight 

 the birds came stringing in almost continuously, sometimes 

 singly or in pairs, and sometimes in groups of from ten to 

 twenty ; often it required alertness to keep the count correctly. 

 On the evening of the thirtieth, at a point about two miles 

 west of where the roost was subsequently found. I counted 

 226 robins and 93 kingbirds. 



On the next evening I went in the opposite direction, and 

 found at some distance southwest of the college, the robins 

 were flying in a direction reverse to that of the night before ; 

 this suggested that the roost might be nearer to the college. 



On the evening of Sept. 1st, the roost was located in a small 

 wooded hollow adjoining the athletic field. The central clump 

 was composed of about fifty rather tall box-elder trees, pretty 

 well crowded together so that the foliage was dense enough 

 and high enough to afiford protection and shelter. To the 

 north there were a good many scattered trees, but on the east 

 there was a large open space occupied by the athletic field, 



