The Red-eyed vireo (Vireo olivaceus) is a small American songbird. It is somewhat warbler-like but not closely related to the New World warblers (Parulidae).
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CrepuscularCrepuscular animals are those that are active primarily during twilight (that is, the periods of dawn and dusk). This is distinguished from diurnal...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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InsectivoresAn insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of e...
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ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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TerritorialA territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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CongregatoryCongregatory animals tend to gather in large numbers in specific areas as breeding colonies, for feeding, or for resting.
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MonogamyMonogamy is a form of relationship in which both the male and the female has only one partner. This pair may cohabitate in an area or territory for...
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Partial MigrantPartial migration is when within a migratory species or even within a single population, some individuals migrate while others do not.
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starts withAdult Red-eyed vireos 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 ).
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Red-eyed vireos breed across Canada and the eastern and northwestern United States. These birds are long-distant migrants traveling to South America, where they spend the winter. The Latin American population occurs in virtually any wooded habitat in their range. Most of these are residents, but the populations breeding in the far southern part of their range (e.g. most of its range in Argentina, Uruguay, Paraguay, and Bolivia) migrate north as far as Central America. Red-eyed vireos breed in deciduous and mixed forests and in open wooded areas. In coniferous areas, they usually occur along stream and river edges. These birds can also be found in groves, city parks, and suburban residential areas. On the wintering grounds in South America, Red-eyed vireos inhabit rainforests, mangrove swamps, dry forests, and plantations.
During the breeding season, Red-eyed vireos are solitary and territorial, however, when migrating and on their wintering grounds these birds often gather in groups of up to 30 individuals and may join mixed-species flocks. Red-eyed vireos are most active during dawn and dusk and prefer to migrate at night. They spend much time feeding in the tree foliage and sometimes hovering while foraging. In some tropical regions, they attend mixed-species feeding flocks, moving through the forest higher up in the trees than the bulk of such flocks. They also often acrobatically reach for fruit, and may even hang upside down. Red-eyed vireos are one of the most prolific singers in the bird world. They usually sing high up in trees for long periods of time in a question-and-answer rhythm. Red-eyed vireos hold the record for most songs given in a single day among bird species, with more than 20,000 songs in one day. They have a large repertoire size with one individual singing 73 different song types.
Red-eyed vireos are primarily carnivores (insectivores) and eat insects, favoring caterpillars and aphids. They also consume berries, especially before migration, and in the winter quarters, where trees bearing popular fruit like tamanqueiro or gumbo-limbo will even attract them to parks and gardens.
Red-eyed vireos are serially monogamous and form pairs only for a single breeding season. They typically nest between mid-April and August. The female constructs the cup-shaped nest in a fork of a tree branch. She lays 3-5 eggs and incubates them for about 11-14 days. The chicks hatch helpless, with eyes closed, and are tended by both parents. They stay in the nest for 10-12 days and become independent after an additional 25 days when the parents stop providing food.
There are no major threats to this species at present.
According to IUCN Red List, the Partners in Flight estimate the global population of the Red-eyed vireo to number 180 million mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.
