SUPPLEMENT TO BIRDS OF ESSEX COUNTY 39 



their breeding-grounds in Labrador have pale greenish-yellow tarsi and feet. 

 Taverner describes these parts as chrome yellow in breeding birds in Alberta and 

 suggests that "it is not impossible that these prairie birds will be found to be 

 distinguishable from the eastern race on the basis of leg coloration."^ It would 

 be interesting to note the color of the legs in adults seen or taken on our eastern 

 coast, and I regret that my notes on this point are unsatisfactory. 



22 [58] Larus atricilla Linn. 

 Laughing Gull; Black-headed Gull. 



Not uncommon transient visitor. July 19 to August 16. 



The only records of this bird for the County in 1905 were a statement by 

 Mr. C. J. Maynard in the " Naturalist's Guide " published in 1870, that he had seen 

 the bird at Ipswich, and two specimens from the County in the Peabody Academy. 

 I referred to the record of eight Laughing Gulls at Metinic Green Island on the 

 Maine coast, and added, " It ought, therefore, to be seen occasionally on the shores 

 of Essex County as a migrant." In 1907, fifty Laughing Gulls nested at Western 

 Egg Rock near Bristol, Maine, and the colony to the south at Muskeget has greatly 

 increased in numbers. For the last six years I have seen one or more of this 

 species at Ipswich nearly every summer. Thus on July 19, 1914, I saw three 

 adults at the mouth of the Ipswich River, and six more on a sand bar at the mouth 

 of the Essex River. 



In flight and feeding habits the Laughing Gull resembles the Herring Gull. 

 Its cry is distinctive and gives it its name. It is a deep ha ha ha followed by 

 rapidly repeated sounds as of rippling laughter. It also emits complaining cries 

 of ai ai and kai kai. 



In all plumages, but especially in the nuptial stage, its markings are dis- 

 tinctive. The adult in summer wears a black hood and the wing-tips for a quar- 

 ter of their length look as if they had been dipped in ink. Seen from above the 

 wings are dark with a white posterior border. The bill and feet are dark red but 

 look black in some lights. The adults in winter and the young lack the black 

 hood, but their dark wings make identification simple. 



1 Taverner, P. A. Auk, vol. 36, p. 8, 1919. 



