1914 J Strong, Habits of the Herring Gull. 35 



They observed much repairing of the nest with green grass or weeds 

 during incubation. 



There is a description ^ of a nest placed 60 feet above the ground 

 and composed of "long, firm, flexible grasses, evidently gathered 

 when green from the salt marshes, and carefully woven into a 

 circular fabric." It is stated that this nest could be handled with- 

 out coming to pieces. 



Herrick - also speaks of the habit of pulling grass " all summer 

 long," which is sometimes carried to the nest, and he gives an inter- 

 esting description of a mid-July revival of the nesting instinct. 



3. Brooding. — According to data given by Dutcher and Baily,* 

 which was reported to them by a resident of the island where their 

 work was done, the period of incubation is a little less than four 

 weeks, usually. The following is taken from their account: "The 

 first egg was found May 15, and the first completed set of three eggs 

 on May 22. The last set of eggs hatched August 3-5. Fifteen 

 nests were marked and watched in order to determine the time occu- 

 pied in incubation, which proved to be as follows : 1 in 24 days; 2 in 

 25 days; 5in-26days; 4 in 27 days; 3 in 28 days." 



As the males cannot be distinguished from females by their 

 plumage, ordinarily, it is difficult to get data concerning the relative 

 parts taken by the two parents in brooding. Dutcher and Daily 

 obtained evidence that both parents take part in brooding the eggs. 

 They state ^ that: " On one occasion, while photographing gulls on 

 nests, it was noted that the first bird that occupied the nest, after 

 the camera was focussed, had a number of dark feathers on its 

 breast; after it had left the nest a bird with a pure white breast 

 occupied it. That this was a mated pair there is no reason for doubt, 

 for they were together, and both exhibited the greatest solicitude for 

 the nest and its contents." They also observed that the stage of 

 incubation could be determined by the increasing anxiety of the 

 parents as the end of the period drew near. On the same page the 

 following occurs : " During the last few hours before the pipping or 



» Baird, Brewer, and Ridgway, Vol. II. The Water Birds of North America, 

 p. 239. 



» Herrick, F. H. Home Life of Wild Birds, p. 163. 

 ' op cit., p. 431. 

 * op. cit., p. 426. 



