° 1914 ] Strong, Habits of the Herring Gull. 43 



to attain the beautiful adult plumage. What appears to be a dark 

 tip to the tail, so prominent in young birds of a certain age, is often 

 retained after increasing whiteness has set the stamp of years, but 

 it is entirely absent in the snowy white tail of the fully matured 

 bird. Birds with pure white tails with the exception of a slight 

 central sprinkling of dusky brown and with a few faint gray streaks 

 in the upper breast, are not uncommon." 



My gulls acquired a yellow iris in the second winter, but they still 

 in their third fall have the bill colored as in the first year. Accord- 

 ing to Astley,^ the bill does not become yellow until the fourth year, 

 although a nearly complete adult plumage appears at the third 

 autumnal molt. Sharpe's account indicates that the adult colora- 

 tion of the beak is not acquired until after the fourth autumn. 



Very meagre data are available as to when breeding begins. A 

 case is described by Dutcher ^ of a gull which apparently began 

 breeding when two years old, and I quote the evidence given for 

 this conclusion as follows. "In response to the question whether 

 the dark colored birds ever mated with the white birds, Mrs. 

 Stanley said that they did when they were two years old. Her 

 reason for this belief was as follows : On one occasion a young gull 

 had lost one of its legs just above the knee. The wound healed 

 but the bird was a cripple and had to hop and stand on the perfect 

 leg. They fed the bird, and it became very tame. In the fall it 

 left with the other gulls and returned with them the next spring, 

 exhibiting its old familiarity. That season when the bird was only 

 one year old it did not mate. It remained on and about the island 

 all the season, departing with the others on their southward migra- 

 tion. The following season it returned again and was still partially 

 dark colored. It secured a white mate and raised a brood of young." 



It is my judgment that Herring gulls rarely breed this early. I 

 saw a few with a very small amount of the immature coloration in 

 their plumage, which were certainly at least two yeajs old. I 

 obtained no evidence that these birds were breeding except the 

 fact of their occurrence with breeding birds at a breeding place. 



> Astley, H. D. My birds in Freedom and Captivity, p. 160. E. P. Button 

 and Co., London, New York, J. M. Dent and Co. 



s Dutcher, "W. Results of Special Protection to Gulls and Terns Obtained 

 through the Thayer Fund. Auk. Vol. XVIII, 1901, No. 1, p. 98. 



