366 NEW YORK STATE MUSEUM 



The family consists of about 75 species, all confined to the Western Hemi- 

 sphere. Evidently the group is of neotropical origin, but several species 

 have invaded the nearctic region, migrating as far north as Canada. 



Vireos are more sedate in habits than warblers, although like them 

 they are characteristically birds of the forest and feeders among the foliage ; 

 but they do not flit so much among the branches, hanging more with their 

 feet and peering about among the leaves and in the axils of the buds search- 

 ing for caterpillars, plant lice, beetles and all species of insects found among 

 the foliage. They must be reckoned among our most beneficial species. 

 The family is more melodious than the Wood warblers, some of the species 

 being our most persistent musicians throughout the summer, although 

 they can not compete in voice with some of the thrushes, thrashers and 

 finches. They all build pensile nests of delicate construction. The eggs 

 are usually 4 in number, white, sparingly spotted with dark brown. 



For detailed accounts of the food of vireos, see Bulletin 17 (Judd, 

 Birds of a Maryland Farm), Biological Survey, United States Department 

 of Agriculture; also Yearbook for 1906, pages 194-95. 



Vireosylva olivacea (Linnaeus) 

 Red-eyed Vireo 



Plate 91 



Muscicapa olivacea Linnaeus. Syst. Nat. Ed. 12. 1 766. 1 : 327 

 Vireo olivaceus DeKay. Zool. N. Y. 1844. pt 2, p. 124, figs. 79 and 75 

 Vireosylva olivacea A. O. U. Check List. Ed. 3. 1910. p. 298. No. 624 

 vireosylva, forest vireo; olivacea, olive-colored 



Description. Upper parts olive green; the crown ash, bordered on the 

 sides by a blackish line, below this a whitish superciliary line, and below 

 that a dusky line through the eye; under parts white slightly tinged with 

 greenish yellow along the sides; iris red; legs leaden blue; bill dusky, paler 

 below. Sexes alike. 



Length 6-6.25 inches; extent 9.75-10.75; wing 3-3.3; tail 2.35-2.5; 

 bill .66; tarsus .75. 



Range. This vireo breeds from British Columbia, southern Mack- 

 enzie, northern Ontario and Cape Breton, to Montana, eastern Colorado 

 and Florida, and farther south along the Rocky mountains; winters in 



