12 NORTH AMERICAK WARBLERS. 



WESTERN MIGRATION ROUTE TO MEXICO. 



The westernmost part of the great migration roate between the 

 Cnited States and the countries to the south is used by the following 

 species that migrate by land to Mexico: 



Lucy warbler {Ilelminihophila lucim). 



Virginia warbler {Helmintliopliila virginise). 



Calaveras warbler [Helminthophila rubricapilla gutturalis). 



Luteacent warbler {Helminthophila celata lutescens). 



Sennett warbler ( Compsothlypis piiiayumi nigrilora) . 



Olive warbler [Dendroica olivacea). 



Sonora yellow warbler (Dendroica eesiiva sonorana). 



Alaska yellow warbler (Dendroica lestiva rubiginosa). 



Audubon warbler (Dendroica auduboni). 



Black-fronted warbler (Dendroica auduboni nigrifrons). 



Grace warbler (Dendroica gracise). 



Black-throated gray warbler (Dendroica nigrescens) . 



Golden-cheeked warbler (Dendroica shrysoparia). 



Pacific yellow-throat (Oeothlypia trichas arizela). 



Townsend warbler (Dendroica lo'umsendi). 



Hermit warbler (Dendroica occidentalis) . 



Grinnell water-thrush (Seiurus noveboracensis nolabilis). 



Macgillivray warbler ( Oeothlypis tolmiei) . 



Western yellow-throat ( Geothlypis trichas occidentalis) . 



Rio Grande yellow-throat ( Oeothlypis poliocephala) . 



Long-tailed chat (Icteria virens longicauda). 



Pileolated warbler ( Wilsoniapusillapileolata). 



Golden pileolated warbler ( Wilsonia pusilla chryseola). 



Painted redstart (Setophaga picta). 



Red-faced warbler ( Cardellina rubrifrons). 



The lines of migration so far given cover the principal routes by 

 which the birds of the United States reach their winter quarters. 

 There is another route which can not be mapped owing to lack of 

 data. Indeed, its existence is largely inferential. Several species 

 that occur in the Mississippi Valley and the Allegheny Mountains 

 rciach Middle America in winter, but are not known regularly in 

 migration in Florida, Cuba, Yucatan, or northeastern Mexico. It is 

 thus certain that these species pass from the Mississippi Valley and the 

 Allegheny Mountains to Middle America, but the point of departure 

 from the United States and the point of arrival in Middle America are 

 not yet known. It seems probable that the birds cross directly to the 

 heavy, damp forests that cover the lowlands of eastern Honduras, the 

 southern parts of Yucatan and Campeche, and the highlands of north- 

 western Guatemala, but not until this region, as yet unvisited during 

 the fall migration, has been thoroughly explored, can any exact knowl- 

 edge on the point be obtained. Species that appear largelj^ to use this 

 route are the following: 



