Quick Answers
Red-eyed and white-eyed vireos are two similar looking songbird species found in North America. The main differences between them are:
- Eye color – Red-eyed vireos have red eyes while white-eyed vireos have white eyes.
- Range – Red-eyed vireos have a wider range across North America while white-eyed vireos are found mainly in the eastern and southeastern US.
- Habitat – Red-eyed vireos prefer deciduous forests while white-eyed vireos like scrubby habitat.
- Song – The songs of the two species are distinct, with the song of the white-eyed vireo being more hurried.
- Nesting – White-eyed vireos nest low in bushes while red-eyed vireos nest higher up in trees.
Naming and Classification
Both the red-eyed vireo (Vireo olivaceus) and white-eyed vireo (Vireo griseus) belong to the vireo family Vireonidae. This family consists of small to medium-sized passerine birds found mainly in North and South America. The genus name Vireo is derived from the Latin word ‘viridis’ meaning green, referring to the predominant greenish color of many vireo species.
The red-eyed vireo was first described scientifically by the American ornithologist Alexander Wilson in 1810. Its specific epithet ‘olivaceus’ is Latin for ‘olive-colored’ referring to its olive-green upperparts.
The white-eyed vireo was given its scientific name Vireo griseus by the English naturalist William John Swainson in 1831. ‘Griseus’ means ‘gray’ in Latin, referring to its gray head and upper breast.
Identification and Field Marks
Despite their similarities, red-eyed and white-eyed vireos can be distinguished by the following key features:
Eyes
As the names suggest, the most obvious difference is eye color – red for the red-eyed vireo and white for the white-eyed vireo. The red-eyed vireo has red irises and dark pupils, while the white-eyed has white irises and pupils. This field mark is diagnostic when seen well.
Plumage
In terms of plumage, the red-eyed vireo has an olive-green crown, back and wings. Its underparts are white with flanks washed in olive-green. It has a white eyebrow stripe and dark lores (region between eye and bill).
The white-eyed vireo has a blue-gray head, greenish back and white underparts. It has a bold yellow spectacle around its white eye and two pale wingbars. The lores are pale yellow.
Bill
The bill of the red-eyed vireo is longer and more curved compared to the shorter stubbier bill of the white-eyed vireo.
Legs
The red-eyed vireo has blue-gray legs, while the white-eyed vireo has pinkish-gray legs.
Distribution and Habitat
The red-eyed and white-eyed vireos occupy different ranges across North America and prefer different habitat types:
Red-eyed Vireo
- Breeding range extends across southern Canada and most of the continental US except for the southwestern deserts.
- Winters in South America as far south as Bolivia and central Argentina.
- Prefers mature deciduous and mixed forests.
- Favors trees like maples, oaks, birches and beeches.
- Avoids dense undergrowth and scrubby habitat.
White-eyed Vireo
- Breeding range restricted to the eastern and southeastern US.
- Winters in Florida, Mexico and down to Panama.
- Inhabits shrubby habitat like scrub, brushy fields and forest edges.
- Prefers habitat with dense vegetation low to the ground.
- More tolerant of disturbed habitat than red-eyed vireo.
The red-eyed vireo has a much wider breeding and wintering range across North America compared to the white-eyed vireo which is limited to the eastern US and southeastern states. The red-eyed vireo prefers mature open forests while the scrubby habitat is prime real estate for the white-eyed vireo.
Migration
Both vireo species are migratory, traveling between their North American breeding grounds and wintering grounds in Central and South America.
Red-eyed Vireo
- Migrates at night using coastal and mountain ridgelines for navigation.
- Spring migration from March to May.
- Fall migration from late August to October.
- Travels over 2500 km between breeding and wintering grounds.
White-eyed Vireo
- Shorter distance migrant compared to red-eyed vireo.
- Northern populations migrate to southeastern US, Mexico and Caribbean.
- Spring migration starts late March to May.
- Fall migration from September to late October.
The red-eyed vireo is a long-distance migrant, traveling thousands of miles between its breeding and wintering grounds twice a year. In contrast, the white-eyed vireo migrates shorter distances since its breeding and wintering ranges have greater overlap in the southeastern US.
Song and Calls
The vocalizations of these two vireos also differ:
Red-eyed Vireo Song
- Sings a series of short phrases separated by pauses.
- Phrases are composed of two to six notes.
- Song has an even, deliberate pace like a plaintive chant.
- Sings persistently from high perches in breeding territory.
White-eyed Vireo Song
- Song is a hurried jumble of short phrases running together.
- Phrases have a distinct nasal quality.
- Song is more hurried, higher-pitched and scratched compared to red-eyed vireo.
- Sings lower in shrubs and scrub rather than high tree perches.
The red-eyed vireo has a more relaxed, crooning song compared to the rushed, scratchy song of the white-eyed vireo. Their songs are so unique that they can be easily told apart once a birder is familiar with them.
Behavior and Ecology
Despite occupying differing habitats, both vireos share some behavioral traits while differing in other aspects of their breeding ecology:
Similarities
- Both are foliage gleaners, picking insects and other arthropods from leaves and branches.
- They are more often heard than seen, staying hidden in foliage.
- Males and females share nest-building, incubation and feeding duties.
- They are persistent singers that stake out breeding territories.
- Their nests are cup-shaped, suspended from forked branches.
Differences
Trait | Red-eyed Vireo | White-eyed Vireo |
---|---|---|
Nest height | 10-40 ft high in trees | 3-10 ft up in shrubs and saplings |
Clutch size | 3-5 eggs | 3-6 eggs |
Incubation period | 12-14 days | 10-13 days |
Fledgling period | 11-14 days | 9-11 days |
The red-eyed vireo nests high in the canopy while the white-eyed vireo nests low in scrubby vegetation. White-eyed vireos also have slightly larger clutches, shorter incubation and quicker fledgling periods compared to red-eyed vireos.
Conservation Status
Both vireo species are common and their populations are considered stable:
- The red-eyed vireo is estimated at 150 million individuals.
- The white-eyed vireo population is estimated at 14 million.
- Habitat loss on wintering grounds is a concern, but overall populations are thriving.
- Predation of eggs and nestlings by jays, crows, squirrels and snakes also occurs.
- Cowbird parasitism affects red-eyed vireos more than white-eyed vireos.
- Neither species is considered threatened or endangered.
The red-eyed and white-eyed vireos remain widespread and common songbirds. Continued protection of their breeding habitats will ensure their populations remain stable into the future. Limiting nest parasitism and predation during the breeding season is also beneficial.
Conclusion
In summary, the red-eyed and white-eyed vireo may appear similar at first glance but can be readily distinguished by differences in eye color, plumage, range, habitat, voice, nesting ecology and behavior. The red-eyed vireo is more widely distributed across North America, preferring mature open forests and deciduous trees for nesting and foraging. It sings slow, deliberate songs in contrast to the hurried scratchy songs of the white-eyed vireo. The white-eyed vireo is restricted to the eastern US and favors scrubby habitat with dense low vegetation. Both species are migratory, traveling to Central and South American wintering grounds each year. While their populations currently seem secure, continued conservation of their breeding and wintering habitat is needed to ensure their numbers remain stable. Careful observation of eye color combined with nuances in plumage, voice and behavior will help birders correctly identify these two similar vireo species.