Eastern Warbling Vireo Life History

Habitat

During the breeding season, Eastern Warbling Vireos inhabit open deciduous woodlands with tall trees, especially cottonwoods, poplars, sycamores, willows, and silver maples. They frequently occur along streams, ponds, marshes, and lakes, and often nest around people, including in neighborhoods, urban parks, and orchards. They are rarely found in purely coniferous forests. During the nonbreeding season, Eastern Warbling Vireos use a variety of wooded habitats, including wooded savanna, pine-oak woodlands, and shade coffee plantations.

Food

Eastern Warbling Vireos eat mainly insects, especially caterpillars, moths, butterflies, beetles, and true bugs (Homoptera). In fall and winter they also add some fruit to their diet. Eastern Warbling Vireos forage mainly in treetops, picking insects from leaves and sometimes twigs; they also hunt by hovering, stalking, hawking, and flycatching. To subdue caterpillars and other larger prey, vireos hit items forcefully against a perch. Breeding pairs forage alone during the breeding season; at other times individual Eastern Warbling Vireos forage in mixed-species flocks.

Nesting

Nest Placement

Eastern Warbling Vireos nest in the outer portions of deciduous trees and tall shrubs from 5 to 60 feet above the ground. The female selects the site, sometimes placing nesting material in several locations before making a final choice.

Nest Description

Eastern Warbling Vireos weave a rough, slightly rounded hanging cup, usually suspending the nest from a horizontally forked twig. The nest may consist of plant matter, cobwebs, lichen, animal hair, and rarely feathers. Nests may contain willow down, dry grass, leaves, rootlets, horsehair, cow hair, spider silk, cocoons, cotton, birch bark, paper, thread, and string. Females do most of the building, sometimes stealing material from the nests of neighbors. The nest is about 3 inches across and 2 to 3 inches deep, with an inner cup about 2 inches across and 1.5 inches deep.

Nesting Facts

Behavior

Eastern Warbling Vireos spend most of their time in the treetops of deciduous woods. Males are highly territorial and spend much of their time during the breeding season singing. They usually arrive on their breeding grounds before females, immediately commencing a singing-and-patrolling campaign to establish and defend territory. During courtship, a male approaches his prospective mate head-on, rhythmically weaving his body from side to side. With quivering wings, he closes the gap between them to about an inch, whereupon the female strikes repeatedly at his open bill with her closed one. While their nest is under construction, a male Eastern Warbling Vireo spends about a third of his time guarding the female. During incubation, the female stays on the nest at night while her mate sleeps in a nearby tree. Both sexes help raise their young to fledging stage, but females do the lion’s share. When parents are feeding young, one adult often waits at the nest until the returning partner signals with a call—ensuring that one parent is always with the nestlings. Both sexes ferociously mob jays, grackles, and other birds that approach their nests.

Conservation

In 2025, ornithologists split Warbling Vireo into two species, Eastern Warbling Vireo and Western Warbling Vireo. Prior to this split, Partners in Flight estimated the global breeding population of Warbling Vireo at 53 million and rated Warbling Vireo an 8 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. According to the North American Breeding Bird Survey, Warbling Vireo numbers increased by approximately 0.6% per year between 1966 and 2019, for a cumulative increase of about 29%.

Eastern Warbling Vireos may benefit from new habitat created when coniferous forests are cleared, leaving large deciduous trees near open spaces. Population declines recorded in the mid-twentieth century have been attributed to the spraying of shade trees with chemical pesticides. Eastern Warbling Vireos also die from collisions with communications towers and other tall structures during nocturnal migration. Because Eastern Warbling Vireos crowd into a winter range disproportionately smaller than their breeding range, habitat conservation there is important.

Credits

AviList Core Team (2025). AviList: The Global Avian Checklist, 2025.

Carpenter, A. M., S. G. Mlodinow, T. Gardali, G. Ballard, P. Pyle, and A. J. Spencer (2025). Eastern Warbling Vireo (Vireo gilvus), version 1.0. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.

Gardali, Thomas and Grant Ballard. (2000). Warbling Vireo (Vireo gilvus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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