314 HABITS OF MACGILLIVRAY'S WARBLER 



in having white eyelids, and in never showing a decided black patch on the 

 breast, which is conspicuous in highly plumaged males of the other form. 

 Whether we are to regard it as a good species or as a geographical race, 

 seems to have settled into a matter of individual preference in nomenclature. 



IN the United States, the two species or varieties of the 

 Mourning Warbler are separated by a considerable inter- 

 val that of the treeless Plains, where neither occurs. The 

 same is the case, for aught we have learned to the contrary, 

 throughout Mexico, where the Philadelphia has not been found. 

 In Central America, however, the two come together, and both 

 are recorded from Costa Eica. Throughout the wooded and 

 watered regions of the West, from the eastern slopes of the 

 Eockies quite to the Pacific, and north at least to British Co- 

 lumbia, Macgillivray's Warbler is sometimes as common as the 

 Maryland Yellow-throat is in the East, and decidedly outnum- 

 bers the latter in its own region. It appears to breed fairly 

 over the whole of this great extent of country, wherever suita- 

 able shrubbery and underbrush grow. I think it has not been 

 shown to winter over our border, although it may very possibly 

 do so in the warmer parts of Southern California, as suggested 

 by Dr. Cooper, and in corresponding localities in Arizona and 

 New Mexico. It has been traced through Mexico to Costa Eica 

 and Guatemala, where Mr. Salvin found that it was a common 

 bird in certain districts. I observed its arrival about Fort 

 Whipple, where it is a not very common summer resident, during 

 the latter part of April, and occasionally noticed it until late in 

 September. Henshaw has seen it in the same Territory and in 

 each of the three neighboring ones, and found that any patch 

 of shrubbery or tangled growth of bushes may be selected as 

 a summer home by one or more pairs, from the lower valleys 

 up to an altitude of about 9,000 feet. In Eastern Colorado, 



Eidgw. Am. Nat. vii. 1873, 199. Goues, BNW. 1874, 75. B. B. < R. NAB. i. 1874, 301, 

 pi. 15, f. 6. Brew. Pr. Bost. Soc. xvii. 1875, 440. Gentry, Life-Hist. i. 1876, 157. ffinot, 

 B. N. Engl. 1877, fft.-Merr. Trans. Conn. Acad. iv. 1877, 23. 



Fanvette petit-deull, V. 1. c. 1823. 



Mourning Warbler, Mourning Ground-warbler, Authors. 



HAB. Eastern Province of the United States and British America, casually 

 to Greenland. West to Kansas, Missouri, and Dakota. South to Costa Rica 

 and New Granada, but no Mexican nor West Indian quotations. No United 

 States wintering record. Breeds in the northern portions of its habitat, as 

 New England, and very abundantly in Minnesota and Eastern Dakota. 

 Common in the Mississippi Valley, but rare along the Atlantic States. (See 

 "Birds of the Northwest", p. 75, for other items.) 



