Philadelphia Vireo
Philadelphia Vireo
Vireo philadelphicus
At a Glance
This bird of the treetops is rather uncommon and often overlooked, or passed off as another vireo species. The Philadelphia Vireo looks somewhat like an Eastern Warbling Vireo or a Western Warbling Vireo, and its song of short phrases sounds much like that of a Red-eyed Vireo. In some places where it overlaps with the Red-eyed Vireo, the two species will even defend territories against each other. Despite its name, the Philadelphia Vireo is only an uncommon migrant around Philadelphia, and does not nest in that region.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Perching Birds, Vireos
IUCN Status
Least Concern
Habitat
Forests and Woodlands, Shrublands, Savannas, and Thickets
Region
California, Eastern Canada, Florida, Great Lakes, Mid Atlantic, New England, Plains, Rocky Mountains, Southeast, Southwest, Texas, Western Canada
Behavior
Direct Flight, Flitter, Rapid Wingbeats
Population
4.000.000
Range & Identification
Migration & Range Maps
Migrates mostly at night. In spring, most fly north across the Gulf and then spread out as they continue northward. Along the Atlantic Coast, more likely to be seen in fall than in spring.
Description
Sexes similar — Length: 5-6 in (12-14 cm); wingspan: 7-8 in (18-20 cm); weight: 0.4-0.5 oz (11-14 g). The Philadelphia Vireo is smaller than either an Eastern Warbling Vireo or a Western Warbling Vireo, with variable yellow below, distinct dark lores (between eye and bill), different song. The yellow is brightest on the central upper chest (Eastern Warbling Vireo and Western Warbling Vireo may show yellow mainly on sides). See Tennessee Warbler.
Size
About the size of a Robin, About the size of a Sparrow
Color
Black, Brown, Gray, Green, White, Yellow
Wing Shape
Rounded
Tail Shape
Notched, Square-tipped
Songs and Calls
Like the Red-eyed Vireo but higher and slower, See-me? Here-I-am! Up-here. See-me?
Call Pattern
Falling, Flat, Undulating
Call Type
Buzz, Chirp/Chip, Whistle
Habitat
Second growth; poplars, willows, alders. Breeds in deciduous and mixed woodlands, especially near their edges, or in the young growth of overgrown pastures. Also nests in willows and alders along streams, lakes, and ponds. In winter in the tropics, often in fairly dry forest in lowlands and foothills.
Sign up for Audubon's newsletter to learn more about birds like the Philadelphia Vireo
Behavior
Eggs
A Philadelphia Vireo generally lays 4 eggs, sometimes 3-5. The eggs are white with brown or black spots near large end. Incubation is by both parents, about 14 days.
Young
Nestlings are fed by both parents. The young leave the nest about 12-14 days after hatching.
Feeding Behavior
Forages mostly in deciduous trees and shrubs, moving about actively as it searches for insects. Often hovers to take items from foliage, or hangs upside down at the tips of twigs to take insects from underside. Sometimes flies out to catch insects in mid-air.
Diet
The Philadelphia Vireo feeds mostly on insects, including caterpillars, moths, beetles, wasps, bees, ants, ichneumons, true bugs, and many others; also some spiders. Eats many berries in late summer and fall, including those of bayberry and dogwood.
Nesting
Male sings to defend nesting territory. In courtship display, male faces female and sways from side to side, fluffing plumage and spreading tail; both members of pair vibrate wings rapidly. Nest site is 10-90 ft above the ground in deciduous tree such as aspen, willow, alder, or maple. Nest is a compact, basket-like cup, its rim woven onto a horizontal forked twig. Nest (built by both sexes) made of grass, strips of birch bark, lichen, weeds, spiderwebs, and cocoons, lined with pine needles, grass, and feathers.
Conservation
Conservation Status
The Philadelphia Vireo could be vulnerable to loss of habitat, especially on wintering grounds. Current populations seem stable.
Climate Threats Facing the Philadelphia Vireo
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.
