Abel — A Winter Robin Roost 169 



i'ortable it seemed advisable to ascertain what effect the 

 weather conditions would have upon the flight. The first 

 Robin flew into the roost at 5 :47 ; they now followed regular- 

 ly at intervals of two or three minutes, at G :06 thirty birds 

 flew in. The watch was now discontinued, as it seemed that 

 the only noticeable change was that the flight started fifteen 

 or twenty minutes earlier than usual. But as there was no 

 cessation in the steady and almost uniform downpour this is 

 attributed to the earlier twilight. 



It was thought desirable to attempt a complete census of 

 the birds arriving from all directions. Accordingly on the 

 evening of Sept. 11, a number of members of the Sioux City 

 Bird Study Club visited the roost and assisted in the count- 

 mg. It was thought that all the birds could be observed by 

 establishing three stations, as follows : the writer undertook 

 to watch the flight from the west ; the southeast quadrant was 

 watched by Dr. Stephens and Mr. Fields ; and the northeast 

 quadrant w^as watched by Mrs. Fields and Miss Hood. Al- 

 together 761 Robins were counted as they entered the roost 

 from all directions. 



The following table sho^\s the only complete census that 

 we made : 



Time West Northeast Southeast Total 



6:04 2 2 



6 :08 2 2 



6:15 3 2 5 



6:16 2 2 



6:17 5 5 10 



6:18 1 1 2 



6 :19 2 2 4 



' 6 :20 16 1 17 



6:21 6 6 



6 :22 19 1 20 



6 :23 2 2 



6 :24 7 7 



6 :2.5 3 3 



6 :26 15 15 



6 :27 2 2 



6 :28 4 4 



