LIFE HISTORIES OF NOliTH AMERICAN GULLS AND TERNS. 117 



October 12 to April 7. The bird was fed regularly with boiled pork 

 and fish. It would fly close to the vessel and would respond to calls 

 or waving of the hand at mealtimes, and it jealously drove off all 

 other gulls. Morris (1903) records another individual that was ob- 

 served for at least 30 years. 



Fall. — The fall migration from the breeding grounds at the Duck 

 Islands, Maine, has been observed by the lightkeepers to begin about 

 August 8, and by the 20th three-quarters of the birds have left. At 

 Ipswich I have noted a decided diminution in the summer birds and 

 a migration past the beach of adults by the 20th of August. As the 

 herring gull is found in summer as well as in winter to the south of 

 the breeding range, it is diificult to set exact limits in time for the 

 migrations. 



The usual explanation given for the occurrence of the herring gull 

 in summer south of its breeding grounds is that these birds are 

 immature or. if adults, barren individuals. On the coast of Essex 

 County, Massachusetts, especially at Ipswich, is a place where non- 

 breeding smnmer birds can be studied to good advantage. Here, 

 on the sandy beaches, they collect in numbers, wliich have notice- 

 ably increased of late years, since adequate protection has been ex- 

 tended to the breeding colonies farther north. As a large proportion 

 of the summer birds at Ipswich are in immature plumage, it is 

 probable that immaturity is the cause for nonbreeding to a con- 

 siderable extent. A certain proportion, however, sometimes as many 

 as 5 or even 10 per cent of the flocks, are in adult pliunage. This fact 

 and the fact that the number of gulls varies greatly from day to 

 day, and that their numbers are greatest at the times when the 

 beaches are covered with stranded fish, suggests that a certain 

 proportion, perhaps only a small one, may be daily excursionists from 

 their breeding places, the nearest of which. No Mans Land, is 111 

 miles northeast of Ipswich Light. Confirming this supposition are 

 some observations made by me in June, 1904. on the Maine coast, 

 where I found flocks of gulls fl.ying southwest in the morning and 

 northeast at night. The following from Dutcher and Bailey (1903) 

 in the study of the gulls at No Mans Land and Great Duck Island, 

 also bears this out : 



At dayliglit large numbers of gulls Icavo the island and go to sea for food ; 

 and the length of tin)e they remain away is governe<l probably by the distance 

 they have to go to find fish. Some days they return quite early and on others 

 much later. The manner of flight when returning from one of these food trips 

 is entirely different from that of the ordinary excursions made from the 

 breeding grounds; it is made close to the surface of the water, very direct, 

 one bird following another, and is quite rapid. Sometimes the birds show 

 marked evidences of fatigue. 



