The Migration of North American Birds 



Compiled by Prof. W. W. Cooke, Chiefly from Data in the Biological Survey 



With a drawing by Louis Agassiz Fuertes 



(See Frontispiece) 



THE BUSH-TIT 



All of the forms of Bush-Tits in the United States are non-migratory. The 

 present species, which is better known by the name of the Least Bush-Tit, is 

 confined to the Pacific Coast, where it ranges from northern Lower California 

 to southern British Columbia. This is the range of the typical form {Psaltri- 

 parus minimus minimus), while a subspecies called the California Bush-Tit 

 {Psaltriparus minimus californicus) occurs over much of eastern California 

 east of the Sacramento Valley, from the southern end of the Sierras nearly to 

 the Oregon line. A third form, or sub-species, the Grinda Bush-Tit {Psaltri- 

 parus minimus grindce), is confined to the southern end of Lower California. 



THE LEAD-COLORED BUSH-TIT 



The southern boundary of the range of the Lead-colored Bush-Tit (Psaltri- 

 parus plumbeus) is found in western Texas, northern Mexico, southeastern to 

 northwestern Arizona, and the Providence Mountains, California. Thence it 

 occurs north to central and northwestern Colorado, northern Utah and north- 

 western Nevada. A few individuals have been noted in southwestern Wyoming 

 and southeastern Oregon. 



LLOYD'S BUSH-TIT 



Scarcely coming across the boundary from its real home in northern Mexico, 

 the Lloyd Bush-Tit {Psaltriparus melanotis lloydi) occurs in the southern part 

 of the mountains of western Texas and barely crosses the line in southwestern 

 New Mexico. 



THE VERDIN 



Confined to the borderland of the southwestern United States, the Verdin 

 in its typical form {Auriparus flaviceps flaviceps) is one of the most interesting 

 birds of the desert and semi-arid districts, and is non-migratory. It ranges 

 north to southeastern California, southern Nevada, northwestern Arizona (and 

 extreme southwestern Utah), southwestern and southeastern New Mexico, 

 western and southern Texas, and south into northern Mexico and the northern 

 half of Lower California. The southern half of Lower California is occupied 

 by a subspecies called the Cape Verdin {Auriparus flaviceps Camprocephalus). 



THE WREN-TIT 



The known ranges of the various forms, or subspecies of the Wren-Tit are 

 given in the following paper. All the forms are non-migratory. 



(97) 



