174 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



blue sky ; as they darted about or dropped suddenly the effect was that of shoot- 

 ing stars. I lay on my back on the bank for some time watching them. As 

 they reached a point over the lake they descended by a series of sudden down- 

 ward shoots or more frequently by a gentle spiral. 



From the southeast the gulls cam-e in immense flocks, low down, larger than 

 I have seen before. At times the stream seemed to extend for what appeared 

 about a mile and was at places dense and broad, at others thin. But the 

 number of gulls was something beyond calculation; it reminded one of the 

 way wild pigeons used to fly. As they approached the water they dropped 

 near the surface and swept up the lake in great clouds to join the great con- 

 course already assembled. This flight of gulls is something that never ceases 

 to interest me ; they are in such vast numbers, so regular in their habits, and 

 so beautiful. 



October 5. The gulls left the lake this morning going northward between 9 

 and 10. Many flew out in flocks directly, but I noticed a new performance. 

 Over the lake a hundred or more gulls would get together and begin to fly 

 about rapidly in a circle, and, others joining them, there was soon formed a 

 great whirling mass of gulls, the bii'ds moving. in all directions within the 

 globe, but turning about when reaching its limits. It was a curious sight, espe- 

 cially as at times five or six of these great whirligigs would be in view at the 

 same time. It was a great game and presented a spectacle of perfect abandon. 

 Fresh flocks encountering one of these merry-go-rounds either passed directly 

 through it or more often joined at once in the sport. Round and round and 

 up and down they went, forming a great whirling mass, which, as a whole, 

 wound slowly onward away from the lake. Sometimes two of these eddying 

 groups encountered each other, and then they merged to form a single one. 

 They broke up finally by the gulls that tired first steering away in the direction 

 of the flight until all had gone. I lay beside a haystack in the warm sun for 

 an hour watching this gull play. The masses formed directly in front of me 

 and passed over and by me at a height of 75 to 100 feet. It reminded me m-ost 

 of the revolving balls of gnats or other insects one sometimes sees on still 

 evenings. The morning was clear, warm, and only a moderate breeze blowing 

 from the norUi. 



DISTRIBUTION. 



Breeding range. — Prairie regions of the northern interior. East to 

 central Manitoba (Shoal Lake) and western Minnesota (Becker and 

 Jackson Counties, Heron Lake). South to northwestern Iowa (Dick- 

 inson County, formerly), northeastern South Dakota (Brookings, 

 Clark, and Marshall Counties), southwestern Saskatchewan (Crane 

 Lake region), and northern Utah (Bear River). West to southeast- 

 ern Alberta (Many Island Lake). North to central Saskatchewan 

 (south and east of the Saskatchewan River) and central Manitoba 

 (Waterhen Lake). 



Winter range. — A few birds winter in the Gulf of Mexico from 

 the coast of Louisiana to Panama, on the west coast of Mexico 

 (Mazatlan) and Guatemala (Chiapam) ; but the main winter range 

 is on the west coast of South America, from northern Peru (Payta) 

 to Patagonia and southern Chile (Magellan). 



Spring migration. — Northward by the most direct route. Dates of 

 arrival: ISiinnesota, Heron Lake, average April 4 and earliest March 



