174 bulletin: museum of comparative zoology. 



Vireo gilvus swainsoni (Baied). 



Western Warbling Vireo. 



Vireosylvia gilva swainsoni BEi,D\SG,'Proc. U. S. Nat. Mus., V. 1883, 549 (Miraflores). 

 Vireo gilvus swainsoni Bryant, Proc. Calif. Acad. Sci., 2d ser., IL 1889, 307 (Mira- 

 flores). 



Although of Late denied recognition by many ornithologists, the form 

 swainsoni is, in my opinion, a good subspecies. Of the several characters 

 which have been claimed for it the be.st are those relating to the bill, which is 

 almost invariably smaller, more depressed, and darker-colored than in true 

 gilvus. The Lower California bird does not appear to differ materially from 

 that of California, Ore^ion, and Washington, but all my specimens from the 

 Pacific slope north of Mexico are smaller than those from the Rocky Mountains, 

 while the latter, in turn, are very decidedly inferior in size to some breeding 

 examples in my collection obtained by Mr. Frazar among the Sierra Madre 

 Mountains of Chihuahua, Mexico. 



Mr. Frazar found the Western Warbling Vireo common on the Sierra de la 

 Laguna in May and early June, and at San Jose del Rancho in July. It was less 

 numerous at Triunfo, probably because of the scarcity of trees in that locality. 

 On La Laguna the birds were paired and apparently about to breed by the 

 middle of May, but at San Jose del Rancho and Triunfo none were found 

 nesting until the middle of July. It was an easy matter to discover their 

 nests, for the male, like that of our eastern form, is in the habit of singing 

 while taking his turn at covering the eggs. 



This Vireo may prove to be resident in the Cape Region, for Mr. Frazar 

 shot a male at San Jose del Rancho on December 23. To the northward it 

 has apparently been detected at but two localities on the Peninsula, — Comondu, 

 where a single specimen was taken on April 12, 1888, by Mr. Bryant, and San 

 Fernando, where Mr. Anthony states that it occurs only during migration, and 

 then but rarely.^ 



V. g. swainsoni is a common summer bird in California and northward to 

 British Columbia. It migrates as far southward as the Isthmus of Tehuan- 

 tepec. 



Vireo solitarius lucasanus Beewst. 



St. Lucas Solitary Vireo. 



Vireosylvia solitaria Baied, Rev. Amer. Birds, pt. I. 1866, 347, 348, part (Cape St. 



Lucas). 

 [Vireo] solitarius CouES, Key N. Amer. Birds, 1872, 121, 122, part. 

 Vireo solitarius Coces, Check List, 1873, 25, no. 127, part. 



1 Auk, XII. 1895, 142. 



