178 Strong, Habits of the Herring Gull. LApril 



ON THE HABITS AND BEHAVIOR OF THE HERRING 

 GULL, LARUS ARGENTATUS PONT. (Concluded.) 



BY K. M. STRONG. 



Plates XIX-XX. 

 VII. Reactions to Stimuli. 



1. Auditory. — I know of no experimental work on the reactions 

 of gulls to sound stimuli, but I have made numerous observations 

 in the field and with my captive gulls which show that hearing 

 is reasonably keen in these birds, especially under certain circum- 

 stances. The bird shown in Plate VII, Fig. 2,^ was easily startled 

 during the earlier part of my tent studies by the small though sharp 

 noises made by the shutters of my cameras. During the course 

 of the day, this gull became less and less sensitive to such noises 

 and to other slight sounds which came from my tent, though one 

 end of the tent was hardly five feet away. The responses finally 

 consisted of little more than short turns of the head. A pistol shot 

 from a boat fully a quarter mile away from shore caused a wild 

 panic on the island. Little attention had been given to the boat 

 before the shot was fired and boats could come nearer without 

 causing a disturbance so long as no shooting occurred. 



On another occasion, the sharp noise made by a falling timber on 

 the beach caused great alarm among gulls which could hardly have 

 seen the fall. Great excitement was caused during the night of my 

 stay on one of the Strawberry Islands by the noise produced by a 

 falling board which was blown down from a position against my tent. 

 It is improbable that many gulls if any could have seen this board 

 fall. The resemblance of such noises to that made by the firing 

 of a gun undoubtedly explains the intensity of the reactions. 

 Many and perhaps all of the adult gulls had learned the significance 

 of a gun shot. 



My captive gulls when tested by some simple experiments om 

 Sept. 27 and 29, 1913, were not much disturbed by any noises which' 



» See Auk, January, 1914. 



