2 Cooke, Routes of Bird Migration. V\^ 



A probable explanation of such sets of records is that these 

 early birds in northeastern Texas, have reached the northeastern 

 coast of Texas by a flight across the Gulf of Mexico, and this long 

 journey, performed in a single night, has carried them north earlier 

 than their fellows which reach southern Texas by a slow land 

 journey from Mexico. 



The Worm-eating Warbler (Helmithcros vermivorus) is a not 

 uncommon migrant in northeastern Texas and is well-known as a 

 winter resident of eastern Mexico, north to Alta Mira. But this 

 species is unknown in southern Texas, though the region from 

 Corpus Christi to the Rio Grande has been carefully searched by 

 competent ornithologists. Here then the birds apparently fly over 

 water to northeastern Texas from the coast of the Gulf of Cam- 

 peche, though the distance to their destination by land through 

 northern Mexico and southern Texas would be but slightly longer. 

 Evidently the birds do not shun a long trip over water. 



The Chestnut-sided Warbler (Deiidroica pensylvanicd) is not 

 uncommon along the whole coast of Texas, but is almost unknown 

 in Mexico; the Mourning Warbler {Geothlypis Philadelphia) is as 

 common on the coast of Texas as anywhere in the United States, 

 but has no certain record for Mexico ; the Green-crested Fly- 

 catcher {Empidonax virescens) breeds in eastern Texas to Corpus 

 Christi, and is known as a migrant south to the Rio Grande, but 

 has only one record in Mexico west of Yucatan ; the Red-eyed 

 Vireo ( Vireo olivaceus) is common in eastern Texas south to Cor- 

 pus Christi, then its numbers become rapidly less, until south of 

 the Rio Grande it has been but twice recorded west of Yucatan. 

 Such records seem to show conclusively that the larger portion of 

 the birds of these species reach the northeastern coast of Texas 

 by a flight across the Gulf of Mexico. 



The above remarks show three different kinds of records, each 

 of which leads to the conclusion that some individuals of the 

 species fly across the Gulf of Mexico to northeastern Texas. 

 More or less strong reasons of a similar nature exist for believing 

 that some individuals of each of the following species, use this 

 same migration route. 



