Warbling Vireo

Vireo gilvus

By Hugh Jennings

  • Length          5.5 in
  • AOU Band code    WAVI

The Warbling Vireo (WAVI) is about 5.5” long.  Its genus Vireo is from Latin meaning ‘a kind of bird.’  The species name is also Latin for ‘pale yellow’.  It is the grayest and palest of our vireos with no wing bars, with the only head marking being an indistinct stripe over the eyes.  It has a whitish breast which sometimes has a yellowish wash.

The WAVI nests throughout the U.S.  It arrives in our state in April or May and heads back south about September.  It occurs throughout the state in deciduous and mixed deciduous-coniferous woodlands at low to moderate elevations.  In Western Washington it favors alders and big-leafed maples.  The birds are hard to see as they forage among the yellow-green, but their song is very distinctive.  F. Schuyler Matthews’ “Field Book of Birds & Their Music” describes it as follows:  “A smooth, continuous flow of about nine or more notes of equal value.  The sound does not resemble a song as much as it does a bit of fantasia, caprice, or the somewhat rapid movement of a sonata.  When the bird begins he runs on until he has finished, without break, pause, or any unevenness whatever.”  A famous ornithologist, T. Gilbert Pearson, likened it to the sentence “If I could see it, I would seize it, and would squeeze it, till it squirts.”

Its diet is mostly insects during the breeding season.  It is more likely to eat berries and small fruits in late summer and fall.  In the west its nest is often placed in a shrub or tree within 30 feet of the ground.  The west, built by both sexes, is a compact, deep cup, suspended by its rim from a forked twig.  The nest is made of bark strips, grass, leaves, and plant fibers.  Usually 4, sometimes 3-5, eggs are laid, white with brown or black specks.  Both parents incubate the eggs for 12-14 days.  The male frequently sings from the nest while incubating.  Sadly, the nests are commonly parasitized by cowbirds.  The young are fed and brooded by both parents and leave the nest 12-16 days after hatching.


Photo by Ollie Oliver

Photo by Ollie Oliver

Red-eyed Vireo

Vireo olivaceus

By High Jennings

  • 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.

Photo by Dan Streiffert

Photo by Dan Streiffert

Hutton's Vireo

Vireo huttoni

By Hugh Jennings

  • Length          4.5-5 in
  • Wingspan      8 in 
  • AOU Band code    HUVI

The Hutton’s Vireo (HUVI) is 4-1/2 to 5" long with a wingspan of 8". The genus name Vireo is from the Latin meaning a kind of bird. The species name huttoni was given in 1851 by John Cassin, Philadelphia ornithologist, for William Hutton, a field collector of birds, about whom little is known. It is a small active bird that is very similar to the Ruby-crowned Kinglet but stockier. The bill is thicker than the kinglet’s and has a slight hook. It has an overall drab olive color with a rounded head and heavy bluish legs. The pale lower wing bar does not have a black bar below as does the Ruby-crowned Kinglet.

The HUVI is generally found in oak woods, moving through the trees with flocks of other small birds. Its range is the woods of the Pacific coast and the southwest. In the Pacific states it may be found in the shrubby understory of humid Douglas-fir and redwood forests. It is mostly a permanent resident but a few show up in the fall and winter along lowland streams where the bird is not present in summer.

It feeds mostly on insects, such as beetles, crickets, spiders and even caterpillars. It forages in trees and shrubs by hopping from twig to twig, pausing to look about as it searches for insects. It sometimes hovers to pick an item from the foliage.

The male sings constantly during the breeding season to defend the nesting terrority. The song is a repeated rising or descending ch-weet ch-weet, repeated in paired notes, the second note either higher or lower than the first, sometimes repeated in a continuous series for 781 times in 11 minutes (Bent,1950). The call is a low chit or whit, whit, or kip, kip, kip.

The nest is built 6-25 feet above ground, usually in oak but sometimes in conifer trees. The nest is built by both sexes and made of bark fibers, lichens, moss, and grass held together with spider webs and lined with grass. There are usually 4 eggs, sometimes 3-5, which are white with brown specks at the larger end. Both parents incubate the eggs for 14-16 days. Cowbirds often lay eggs in HUVIs nests. Both parents feed the young which leave the nest from 14-17 days after hatching. Occasionally there are two broods each year.

Photo by Ollie Oliver

Photo by Ollie Oliver