Vireo gilvus
(Warbling Vireo)

Physical Description:
4 1/2-5 1/2" (11-14 cm). Dark gray above, pale gray or white below; whitish eyebrow and dark eyes. Immatures tinged yellow below.

Similar Species- Philadelphia Vireo

Song:
Long, continuous warble with no pauses. Call is a raspy pwchee-chee.

Distribution:
Breeds from British Columbia, east across portions of Canada to northern Michigan, further east to Nova Scotia, and south to Baja California, northern Mexico, Texas, and portions of southeastern United States. Winters from northern Mexico to Nicaragua, and casually to Costa Rica.

Habitat:
Found in open, deciduous and deciduous/coniferous woodlands, riparian forests and thickets, pine/oak associations, orchards, and parks. During migration and in winter, found in wide variety of forest, woodland, and scrub habitats; seems to prefer light woodlands and savanna groves in winter. Idaho study found species was associated with dry, tall, willow areas.

Diet:
Primarily insectivorous. Feeds on caterpillars, beetles, grasshoppers, ants, spiders, and some berries.

Ecology:
Forages in trees. Builds cup-shaped nest, usually high in tree, but sometimes in shrub. density figures of 13.4 birds/40 ha have been recorded in flatland aspen; 60.0/40 ha in scrub-meadow; and 5 pairs/40 ha in Douglas-fir forest. Species is common cowbird host.

Reproduction:
Male and female, in turn, incubate 4 eggs (sometimes 3-5), for about 12 days. Nestlings are altricial and downy, are tended by both parents, and leave the nest in about 12-14 days.

Conservation:

Element Code:	ABPBW01210
Status:	Protected nongame species
Global Rank:	G5
State Rank:	S5,NTMB
National Rank:	N5B

Important State References:
Douglas, D.C., J.T. Ratti, R.A. Black, and J.R. Alldredge. 1992. Avian habitat associations in riparian zones of Idaho's Centennial Mountains. Wilson Bull. 104:485-500.