56 North ameeican warblers. 



eastern line of migration southward migrants have been noted Jn cen- 

 tral Florida July 20, and by the last week in July the birds are in 

 full tide of migration at New Orleans. Fall migrants have been 

 recorded at the following places on the dates named: Key West, July 



26, 1889; southeastern Nicaragua, August 9, 1892; San Jose, Costa 

 Rica, August 25, 1889, and August 24, 1890; Bonda, Colombia, August 



27, 1898. 



Cherrie says of yellow warblers migrating through Costa E.ica: 

 They made their first appearance in the fall of 1889, August 25, on which date a 

 number were seen. Those taken were very fat. From this date they were com- 

 mon, and by September 17 abundant. Then the numbers seem to have diminished, 

 until during October, November, December, and January they were only tolerably 

 common. During the latter part of January and the first of February they were the 

 most common warbler in the vicinity of San Jos6. From this time they were com- 

 mon until the first of May. None of those taken last showed any signs of breeding." 



The bulk of the birds pass southward soon after the early migrants. 

 Following are some of the records of last-noted migrants: Near lati- 

 tude 64^ north of Fort Rae, Mackenzie, August 10, 1903; Great Falls, 

 Mont., September 13, 1889; Lanesboro, Minn., September 10, 1889; 

 Ottawa, September 7, 1901; North River, Prince Edward Island, 

 August 20, 1889; St. John, New Brunswick, September 2, 1890; 

 Montreal, September 3, 1890; Lewiston, Me., September 5, 1898; 

 Providence, R. 1., September 4, 1901; Englewood, N. J., September 

 1, 1886; Germantown, Pa., September 24, 1887; "Washington, Sep- 

 tember 28, 1890; Raleigh, N. C, August 28, 1888; Asheville, N. C, 

 September 1, 1890; Frogmore, S. C, September 28, 1886; Grin- 

 nell, Iowa, August 24, 1887; Chicago, September 6, 1899; St. Louis, 

 September 3, 1896; Onaga, Kans., August 24, 1894; Bonham, Tex., 

 September 12, 1889; New Orleans, October 27, 1893. 



Though in migration the yellow warbler occurs in Florida as far 

 south as Kej' West and is sometimes fairly common in northern 

 Florida, the numbers that migrate through the southern part of the 

 State must be very small, for not a bird passing north or south has 

 been reported from anj^ of the Florida lighthouses. The migration 

 route of the yellow warblers that breed near the Atlantic coast is evi- 

 dently southwest to northern Georgia and Alabama, and then across 

 the Gulf of Mexico. 



652a. Dendroica aastiva sonorana Brewst. Sonor'a Yellow Warbler. 



This southwestern subspecies of the yellow warbler nests in north- 

 western Mexico, southern Arizona, southern New Mexico, and western 

 Texas, and extends its breeding range northward until it meets the 

 eastern form approximately in central New Mexico. It retires to 

 Mexico and Guatemala for the winter, but its range in these countries 

 has not yet been satisfactorily determined. 



"Cherrie, Auk, VII, 3.35, 1890. 



