Red-eyed Vireo

Vireo olivaceus

eBird gives this description for the Red-eyed Vireo:  Plain olive-green above and whitish below with no wingbars. Red eye of adults is not always easy to see; immatures have brown eyes. Dark stripe through and above eye. Larger and thicker-billed than warblers. Breeds in mature deciduous forest. Often sings nearly nonstop throughout the day; listen for repetitive musical phrases coming from the treetops. Often with flocks of chickadees and warblers during migration. Winters in South America, where it could be confused with the very similar Chivi Vireo. Best distinguished by voice.  All About Birds provides this additional descriptive information for the Red-eyed Vireo:  A tireless songster, the Red-eyed Vireo is one of the most common summer residents of Eastern forests. These neat, olive-green and white songbirds have a crisp head pattern of gray, black, and white. Their brief but incessant songs—sometimes more than 20,000 per day by a single male—contribute to the characteristic sound of an Eastern forest in summer. When fall arrives, they head for the Amazon basin, fueled by a summer of plucking caterpillars from leaves in the treetops.

I saw my first Red-eyed Vireo at the Quintana Neotropical Nature Preserve on the morning of April 18, 2021.  On that same birding trip, I saw the Red-eyed Vireo two days later at Sabine Woods.  For my blog post about this birding trip, look here. 

Red-eyed Vireo at Quintana Neotropical Bird Preserve on the morning of April 18, 2021.
Red-eyed Vireo that I watched at Sabine Woods on the afternoon of April 20, 21 (at the central drip blind).


“Cool Facts” About The Red-eyed Vireo From All About Birds:

  • The red iris that gives the Red-eyed Vireo its name doesn’t develop until the end of the birds’ first winter. Then the brown iris the birds were born with becomes dull brick red to bright crimson in different individuals.
  • Some find the Red-eyed Vireo’s song unending and monotonous. Bradford Torrey wrote in 1889, “I have always thought that whoever dubbed this vireo the ‘preacher’ could have had no very exalted opinion of the clergy.” But each male sings 30 or more different songs, and neighbors have unique repertoires. Over 12,500 different Red-eyed Vireo song types have been recorded.
  • On May 27, 1952, Louise de Kiriline Lawrence counted the number of songs sung by a single Red-eyed Vireo seeking a mate on his territory 180 miles north of Toronto. He sang 22,197 songs in the 14 hours from just before dawn to evening, singing for 10 of those hours.
  • From the 1920s to the 1940s Red-eyed Vireos expanded west into Utah and Oregon and northeast into Newfoundland. The most likely cause is new shelterbelts and landscaping, particularly where eastern tree species were planted. Since the 1970s, however, numbers in the Big Basin region of the West seem to have fallen steadily.
  • Several subspecies of Red-eyed Vireos remain resident in South America or migrate only within that continent.
  • The Red-eyed Vireo’s magnetic compass guides migration between continents. But fat stores seem to influence migration paths when the birds encounter the Gulf of Mexico. Fatter birds head across the Gulf, while leaner birds hug the coastline or travel inland around the Gulf. Cloud cover also makes routes near land more likely.
  • The oldest known Red-eyed Vireo was at least 10 years, 2 months old when it was recaptured and rereleased during banding operation in Maryland.