Warbling Vireo
Vireo gilvus

Migratory Status: Neotropical migrant

PIF Population Estimate: 22 000 000

Percent of western hemisphere population breeding in boreal forest: <25%

BAM Effective Detection Radius (m) : 69.59

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: 1.3 (0.6 to 2.1)

Life History

The Warbling Vireo is a common and widespread breeding bird in North America. Its rather complex, warbling song, while sung loudly and frequently, tends to blend in with the songs of other, more familiar species, making it difficult to detect. A drab, gray-olive appearance combined with a preference for thick, dense deciduous forests also makes the Warbling Vireo a difficult species to locate and identify.

The breeding range extends from southeast Alaska, southeast Yukon, and south-western Northwest Territories, east to northern Nova Scotia. The northern border of the breeding range follows the northern deciduous forest boundary, which roughly follows the bottom third of the Prairie provinces, southern Ontario, and southern Quebec. The southern extent of the breeding range includes almost the entire mainland United States, with the exception of the extreme southeast. Breeding populations also exist in Baja California, along with northern portions of the Pacific coast in Mexico. The primary wintering range extends from western Mexico and northern Central America, south to northwestern Nicaragua.

As with most members of the family Vireonidae, the diet throughout the year, especially during the breeding season, consists largely of insects, which are generally caught while in flight, or rarely, taken directly from foliage. During migration and on the wintering grounds, fruit and berries may become an important component of an adult’s diet.

Reference(s)

Gardali, T., and G. Ballard. 2000. Warbling Vireo (Vireo gilvus), The Birds of North America Online, . A. Poole, Ed. Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: http://bna.birds.cornell.edu/bna/species/551