NORTH AMERICAN GULLS AND THEIR ALLIES. 61 
Fall migration. — The most pronounced characteristic of the fall 
migration of Bonaparte's gull is its early date of beginning. At 
Okanogan Lake, British Columbia, the average date of its arrival 
in southward migration is July 21, earliest July 9, 1911 (Brooks); 
this species was noted at Lake Iliamna, Alaska, July 16, 1902 
(Osgood); a flock appeared at Erie, Pa., July 4, 1909 (Simpson); 
one at Ithaca, N. Y., July 24, 1908 (Reed and Wright); Portland, 
Me., July 27, 1908 (Eastman); Chicago, 111., July 15, 1906 (Arm- 
strong); on the Yellowstone River, Mont., July 31, 1905 (Cameron); 
and on the Laramie River, Wyo., July 23, 1857 (Knight). 
Probably the normal beginning of fall migration is represented 
by the numerous birds present at York Factory, Keewatin, July 
17-22, 1900 (Preble), and the continuation of this movement is 
is noted at Baddeck, Nova Scotia, August 4-16, 1886 (Dwight) ; 
Portland, Me., August 9, 1905, and August 4, 1906; Charlestown, 
N. H., August 3, 1897 (Buswell); Monomoy, Mass., August 13, 
1885 (Cahoon); Point Judith, R. L, August 5, 1900 (Hathaway); 
Erie, Pa., August 20, 1890, and August 13, 1902; Atlantic City, 
N. J., August 21, 1892 (De Haven); Charleston, S. C, August 20, 
1909 (Wayne) ; Coronado, Fla., earliest September 16 (Longstreet) ; 
Chicago, 111., average August 21, earliest August 17, 1907; Oberlin, 
Ohio, average September 4, earliest August 11, 1910; Moose Factory, 
Ontario, August 11, 1860 (specimen in U. S. National Museum); 
Toronto, Ontario, August 4, 1890 (Fleming) ; Ottawa, Ontario, Aug- 
ust 24, 1887 (White); Delavan, Wis., August 26, 1892 (Hollister); 
southern Manitoba, average August 31, earliest August 15, 1899; 
and on the coast of Los Angeles County, CaL, common after 
August 20, 1910 (Willett). The foregoing dates are the records of 
a comparatively few individuals, most probably nonbreeders or those 
that lost their eggs or young. The great bulk of the birds move a 
month to six weeks later. They are most numerous along the New 
England coast in October and reach the coast of southern California 
in early November. 
The average date of the last one seen at Montreal, Canada, was 
September 26, latest October 1, 1892 (Wintle); North River, Prince 
Edward Island, average November 20, latest November 25, 1888 
(Bain); Woods Hole, Mass., December 23, 1892 (Edwards); near 
Oberlin, Ohio, December 17, 1906, and January 6, 1908 (Jones) ; 
Toronto, Ontario, November 25, 1898 (Nash), and December 15, 
1897 (Fleming); Birch Lake, Alberta, October 13, 1909 (Brooks 
and Cobb); Fort Good Hope, Mackenzie, as late as October, 1864 
(specimen in U. S. National Museum) ; Margaret, Manitoba, average 
October 19, latest October 24, 1910 (Black); Aitken, Minn., Novem- 
ber 2, 1902 (Lano); Lincoln, Nebr., November 3, 1896 (Bruner) ; 
Pueblo, Colo., November 15, 1895 (Nash); Unalaska Island, Alaska, 
