Bird of the Month: Red-eyed Vireo
By High Jennings
PC: Greg Pasek/Audubon Photography Awards (Red-eyed Vireo)
Scientific Name: Vireo olivaceus
Length 6 in
Wingspan 10 in
AOU Band code REVI
The Red-eyed Vireo (REVI) is about 6” long with a wingspan of 10”. The genus name Vireo (VIH-ree-oh) is from Latin vireo, a kind of bird; according to some , the green finch; virere, to be green. The species name olivaceus (ol-ih-VAY-see-us) is Latin, olive-colored; green obscured with neutral tint. It has two eyebrows - a white one and a black one above it, with a dark eyeline and gray cap. The back is dark olive with darker wings and tail and white under-parts. It does not have any wing bars. The ruby-red eye is visible at close range. The REVI is one of the most numerous summer birds in eastern woods. It is not the most often seen as it tends to stay out of sight in the leafy treetops, searching methodically among the foliage for insects.
During the breeding season it is found in eastern U.S., across the northern states into Washington, and throughout Canada. It breeds in deciduous and mixed forest, sometimes in conifers. Also, well-wooded suburbs, orchards and parks. The REVI is regularly seen locally in Marymoor Park from late May throughout the summer. It winters in lowland tropical forests in Central and South America. Those breeding in the northwest apparently fly east in the fall before turning south. Migration occurs mostly at night. It eats mostly insects, but also eats wild fruits and berries. The nest is made of fine grasses, rootlets, paper, grapevine bark, spider web and decorated with lichens. The nest is place in a horizontal tree or shrub branch from 2-60 ft. above ground. The female does all of the nest building and incubation. There are 3-5 eggs, white with dark marks. Incubation is 11-14 days and the young leave the nest 10-12 days after hatching. There may be two broods in a summer.
The REVI has a persistent song that is sung all day. The song is a series of short, monotonous phrases, as if it were endlessly asking and answering the same question. During incubation, the male sings faster, 50-60 phrases a minutes. When he stops, the female comes off the nest and he feeds her, or they feed together. She then resumes incubation. This species is one of those most frequently parasitized by cowbirds.