The Red-eyed Vireo, Vireo olivaceus, is a small American songbird, 13-14 cm in length. It is somewhat warbler-like but not closely related to the New World warblers (Parulidae). Common across its vast range, this species is not considered threatened by the IUCN.
Description and systematics
Adults are mainly olive-green on the upperparts with white underparts; they have a red iris and a grey crown edged with black. There is a dark blackish line through the eyes and a wide white stripe just above that line. They have thick blue-grey legs and a stout bill. They are yellowish on the flanks and undertail coverts (though this is faint in some populations).
This bird, not always seen, may sing for long periods of time; it appears to be endlessly repeating the same question and answer. It holds the record for most songs given in a single day among bird species.
The subspecies breeding in South America have a simpler song, a chestnut iris, and different remiges proportions. They are sometimes split as the Chivi Vireo, V. chivi. Some of the races concerned are V. o. chivi, V. o. vividior, and V. o. tobagoensis, the last being a relatively large subspecies endemic to Tobago. Even within the Chivi Vireo, there are distinct variations in measurements, song and ecology, but the possible taxonomic significance of this remains unclear.
In the past, the Yellow-green Vireo (V. flavoviridis) and the Noronha Vireo (V. gracilirostris) have been considered as subspecies of the Red-eyed Vireo.
The breeding habitat is open wooded areas across Canada and the eastern and northwestern United States. These birds migrate to South America, where they spend the winter. The Latin American population occur in virtually any wooded habitat in their range. Most of these are residents, but the populations breeding in the far southern part of this species' range migrate north as far as Central America.
This vireo is one of the more frequent American passerine vagrants to western Europe, with more than one hundred records, mainly in Ireland and Great Britain. In northern Ohio, it seems to return to breed at about the same time as one century ago; intriguingly, it might actually leave for winter quarters one or two weeks earlier at present than it did in the past.
Red-eyed Vireos glean insects from tree foliage, favouring caterpillars and aphids and sometimes hovering while foraging. In some tropical regions, they are commonly seen to attend mixed-species feeding flocks, moving through the forest higher up in the trees than the bulk of such flocks.
They also eat berries, especially before migration, and in the winter quarters, where trees bearing popular fruit like Tamanqueiro (Alchornea glandulosa) or Gumbo-limbo (Bursera simaruba) will even attract them to parks and gardensFoster (2007). Cymbopetalum mayanum (Annonaceae) is visited far less frequently.. Fruit are typically not picked up from a hover, but the birds often quite acrobatically reach for them, even hanging upside down.
The nest is a cup in a fork of a tree branch. The Red-eyed Vireo suffers from nest parasitism by the Brown-headed Cowbird (Molothrus ater) in the north of its range, and by the Shiny Cowbird (M. bonariensis) further south. Parasitism by HaemoproteusHaemoproteus vireonis and perhaps some other species . and trypanosomans might affect these birds not infrequently, as was noted in studies of birds caught in Parque Nacional de La Macarena and near Turbo (Colombia): though only three Red-eyed Vireos were examined, all were infected with at least one of these parasites.Basto et al. (2006), Londono et al. (2007)
(2006): Haematozoa in birds from la Macarena National Natural Park (Colombia). Caldasia 28(2): 371-377 [English with Spanish abstract]. PDF fulltext
(1991): A guide to the birds of Trinidad and Tobago (2nd edition). Comstock Publishing, Ithaca, N.Y.. ISBN 0-8014-9792-2
(2007): The potential of fruiting trees to enhance converted habitats for migrating birds in southern Mexico. Bird Conservation International 17(1): 45-61.
(1906): A preliminary list of the birds of Seneca County, Ohio. Wilson Bull. 18(2): 47-60. DjVu fulltext PDF fulltext
(2003): Birds of Venezuela. Christopher Helm, London. ISBN 0-7136-6418-5
(2007): Blood Parasites in Birds From the Lowlands of Northern Colombia. Caribb. J. Sci. 43(1): 87-93. PDF fulltext
(1999): A composicao dos bandos mistos de aves na Mata Atlantica da Serra de Paranapiacaba, no sudeste brasileiro [Mixed flocks of birds in Atlantic Rain Forest in Serra de Paranapiacaba, southeastern Brazil]. Revista Brasileira de Biologia 59(1): 75-85 [Portuguese with English abstract]. PDF fulltext
(2004): Annotated Ohio state checklist. Version of April 2004. PDF fulltext
(2006): Avifauna dispersora de sementes de Alchornea glandulosa (Euphorbiaceae) em uma area de mata ciliar no estado de Sao Paulo [Seed dispersal of Alchornea glandulosa (Euphorbiaceae) by birds in a gallery forest in Sao Paulo, southeastern Brazil]. Revista Brasileira de Ornitologia 14(3): 291-296 [Portuguese with English abstract]. PDF fulltext
Red-eyed Vireo - Vireo olivaceous - USGS Patuxent Bird Identification InfoCenter
Red-eyed Vireo Species Account - Cornell Lab of Ornithology
Red-eyed Vireo Information and Photos - South Dakota Birds and Birding
Stamps with RangeMap
Red-eyed Vireo videos - on the Internet Bird Collection
Red-eyed Vireo photo gallery VIREO Photo-High Res--(Close-up)
Red-eyed Vireo Bird Sound
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Red-eyed Vireo