24 Strong, Habits of the Herring Gull. [jan. 



islands, I thought it best to stay at Ephraim and depend upon small 

 boats for transportation whenever a visit was made to the gull 

 colonies. Unfortunately, boats were not always available and the 

 weather was not favorable on many days. Work was carried on at 

 the Sister Islands on June 26, July 12, and July 15; at Middle 

 Strawberry Island on June 30 and July 29; and at Gravel Island 

 July 18 and 19. Another period was spent at Middle Strawberry 

 Island beginning at 7: 20 P. M., July 7 and ending the next day at 

 7:05 A. M. So much time was taken by preliminary studies that 

 my experimental work at the breeding places was barely begun 

 when the season ended. 



Other experiments were begun with some ju venal gulls which 

 were taken from their nesting places to Ephraim and were kept in a 

 pen (See Plate IV, Fig. 2). These birds were removed to Chicago 

 in August where experiments with them are still in progress. Ref- 

 erences will be made in this paper to observations made on these 

 captive gulls. The work in Chicago has been made possible through 

 the kindness of Professors Angell and Carr of the Department of 

 Psychology, in giving me outdoor cage accommodations. 



The only species of gull discussed in this paper except where 

 otherwise stated, is the Herring Gull. 



II. Methods. 



Like other observers, I found a tent or blind indispensable for the 

 study of the birds at their breeding places. On approaching a 

 breeding colony of gulls a wild panic begins which does not cease so 

 long as the intruder appears to be in the immediate vicinity. 



I had a tent made similar to that described by Sawyer,^ with 

 some modifications. It was about four feet high and six feet long 

 at the bottom. The cover was made from dark green cambric 

 lining cloth, costing seven cents a yard. The entire cover could be 

 folded into a package small enough to go into a coat pocket. 



After the first trip, extra openings were made to facilitate taking 



1 Sawyer, E. J. A Special Bird-Blind. Bird Lore, Vol. XI, no. 2, March-April, 

 1909, pp. 71-73. One page of text figures. 



