LIFE HISTOBIES OF NORTH AMERICAN GULLS AND TERNS. 175 



27; Manitoba, Aweme, average April 25 and earliest April 8; Sas- 

 katchewan, Indian Head, average May 3 and earliest April 25. Tran- 

 sient dates : Missouri, April 20 to May 15 ; Kansas, April 10 to June 

 9; Iowa, April 6 to June 27. Late dates of departure: Peru, Callao 

 Bay, April 11; Guatemala, Champerico, May 30; Texas, Kerrville, 

 May 17 and Aransas Bay, June. 



Fall migration — A reversal of the spring route, but more erratic. 

 First arrivals reach Chile, Valparaiso, in September. Late dates of 

 departure; Minnesota, Madison, October 8; Iowa, November 6; Ne- 

 braska, Lincoln, November 17 ; Texas, Brownsville, November 10. 



Casual records. — Has wandered on migrations to Hudson Bay 

 (specimen in British Museum from Hayes River) ; Pennsylvania 

 (Philadelphia, October 22, 1911) ; Virginia (Blacksburg, October 24, 

 1898) ; the West Indies (St. Bartholomew Island) ; California (Hy- 

 perion, October 17 and November 24, 1914) ; and many other inland 

 localities. Accidental in Hawaiian Islands (Mauai, winter). 



Egg dates. — Minnesota and North Dakota : Forty-two records, May 

 3 to June 26 ; twenty-one records, May 18 to June 4. Manitoba and 

 Saskatchewan: Twenty-one records, June 5 to 16; eleven records, 

 June 6 to 11. 



LARUS PHILADELPHIA (Ord). 



BONAPAETE'S GULL. 

 HABITS. 



This widely distributed American species is found at some season 

 of the year in nearly all parts of our continent. As it retires to the 

 northern wooded regions of Canada to breed, it is familiar to most of 

 us only as a migrant or a winter visitor, and few naturalists have 

 studied it on its breeding grounds. During the first warm weather 

 in April, when the shad and herring are beginning to run up our 

 rivers, we begin to see the migrating flocks of this pretty little gull 

 moving northward along our coasts or up the valleys of our great 

 rivers in the interior. They proceed in a leisurely manner, drifting 

 along in loose flocks, as if aimlessly wandering, stopping to dip down 

 and occasionally pick some morsel of food from the surface of the 

 water, chattering to each other in soft conversational notes, or 

 coursing over the meadows and marshes to catch the first flying in- 

 sects of spring. The black-headed adults make up the vanguard of 

 the migrating hosts, followed later by the immature birds ; flocks of 

 young birds, however, often have one or two adults with them as 

 leaders. Sir John Kichardson (1851) says: 



This species arrives very early in the season, before the ground is de- 

 nuded of snow, and seeks its food in the first pools of water which form on 

 the borders of Great Bear Lake, and wherein it finds multitudes of minute 

 crustacean animals and larvae of insects. 



