235 



628. Vireo flavifrons Vieill. [140.] Yelloiv-throated Vireo. 



In summer this Vireo is dispersed throughout the Mississippi Valley, 

 but it is rare in Manitoba. In winter it is not found north of Florida. 

 In 1881 it must have crossed our border very early, as it appeared at 

 Gainesville, Tex., March 6. Saint Louis was reached April 17. At 

 Manhattan, Kans., where it is rare, it was seen May 3; at La Porte 

 City and Waukon, in Iowa, May 5; and Lanesboro, Minn., May 10. It 

 was first seen at West Depere, Wis., May 7. 



In the fall of 1884 the bulk of Yellow-throated Vireos left Williams- 

 town, Iowa, August 11, and none were seen there after that date. At 

 Mount Carmel, Mo., the last was seen September 21. 



In the spring of 1885 the first came to Gainesville, Tex., April 6, and 

 they were commom there April 17. At Saint Louis, Mo., they appeared 

 April 20. They were seen at Chicago, 111., April 21; at Manhattan, 

 Kans., April 22; Mount Garmel, Mo., April 23; Eockford, 111., May 9; 

 Iowa City, Iowa, May 10; Waukon, Iowa, May 10; and Durand, Wis., 

 May 15. 



In the fall of 1885 the last was seen at Grinnell, Iowa, September 10; 

 at Mount Carmel, Mo., September 20; and at Saint Louis, where they 

 were numerous September 26, the last was seen October 12. 



629. Vireo solitarius (Wils.). [141.] Blue-headed Vireo. 



This Vireo winters below our southern border, and breeds principally 

 in Manitoba and the Northern States, occasionally as far south as the 

 40th parallel, and in a few rare instances still farther south. 



In 1884 it was reported from Saint Louis April 29 ; and from no other 

 station previous to May 10, but on that day it appeared simultaneously 

 at Burlington and Des Moines, Iowa, and at Minneapolis and Elk Eiver, 

 Minn. This same day the last one was seen at Saint Louis, making its 

 stay there only eleven days ; so that not only did the van move rapidly, 

 but the species as a whole must be one of the most rapid migrants in 

 the Mississippi Valley. 



In 1883, when calculating the average speed of migration for more than 

 a hundred species, it was found that the Solitary Vireo had the highest 

 rate. It seemed to advance all at once, and its rate of speed was esti- 

 mated at more than 80 miles a day. In 1884 its rate seemed to have 

 been much the same. 



In the spring of 1885 the record of the migration of the Solitary Vireo 

 was so irregular that, while its character as a rapid migrant was main- 

 tained, no average rate of speed can be calculated from it. The whole 

 record received is as follows : At Mount Carmel, Mo., and La Porte 

 City, Iowa, the first were noted April 26 ; Paris, 111., April 28 ; Saint 

 Louis, Mo., April 30; Waukon, Iowa, May 3; Delaware, Wis., May 7, 

 and Lanesboro, Minn., May 7. 



The record of "lasts" was still more irregular. It is as follows: La 

 Porte City, Iowa, April 27 ; Mount Carmel, Mo., May 3 ; Des Moines, 

 Iowa, May 8 ; Saint Louis, Mo., May 13 ; Waukon, Iowa, May 15. 



