Vireo olivaceus
Plate — illustration to come
Summer breederNative · New Jersey

Red-eyed Vireo

Vireo olivaceus

Vireonidae

The most persistent summer singer in the eastern North American forest. Red-eyed Vireos have been recorded singing 20,000+ times in a single day — every 3 seconds through July. Small, olive-and-white, with a bold face pattern and the diagnostic ruby-red eye. Almost always heard before seen; heard constantly.

Arrives in May; departs September for tropical South American wintering grounds.

Identify by

How to spot one.

  • 5 inches, sleek warbler-like build

  • Olive-green back, clean white underparts

  • Distinctive face pattern: gray cap, black eye-line, white eyebrow

  • Ruby-red eye (juveniles have brown eyes)

  • Usually high in the tree canopy

Voice

What it sounds like.

Endless short warbled phrases with a slight pause between each, in a rising-and-falling cadence — described as 'Here I am! Where are you? Up here! In the tree!' Sings continuously through midday when most songbirds go quiet.

Life & behavior

How it lives.

Canopy forager — gleans caterpillars and small insects from the underside of leaves. Nests low in shrubs and saplings (unusual for a canopy bird). Hovers briefly to pluck prey.

At a glance

The spec sheet.

Status
Summer breeder
Size
4.7–5.1 inches
Present in NJ
May – September
Native to NJ
Yes
Conservation status
stable
Family
Vireonidae
Diet

What it eats.

Diet often shifts dramatically between breeding season and the rest of the year — especially for insectivorous birds that pivot to native berries in fall and winter.

Summer / breeding season

  • Caterpillars — dominant summer food

  • Beetles, moths, aphids, small wasps

  • Spiders

  • Some berries late in season

Fall / winter

  • Migrates to Colombia, Venezuela, and Brazil

  • Winter diet: primarily fruit — figs, native tropical berries

Plants it uses

What it needs.

Native plants that feed this bird or provide shelter. Names in hydrangea link to the plant’s Field Guide entry.

  • Mature deciduous forest

    Cover / habitat

  • Native oaks

    Larval host tree (feeds caterpillars)

  • Wild black cherry

    Larval host tree (feeds caterpillars)

  • Arrowwood Viburnum

    Fruit / berry source

  • Native dogwoods, sassafras

    Fruit / berry source

Sources

Audubon Field Guide · All About Birds (Cornell) · NJ Conservation Foundation