Red-eyed Vireo

How to find it

Numbers change from day to day as waves of migrants pass through, so a quiet morning can be followed by a busy one. Look for scattered groups joining mixed flocks of resident birds and other migrants. Scan higher in the trees, since it feeds above most of the flock. In fall the first migrants often show up with flocks of kites, Eastern Kingbirds and wood-pewees. On the Caribbean slope, mixed flocks held Red-eyed Vireos alongside White-ringed Flycatcher and Lesser Greenlet. The species is mainly visible on the Caribbean side, and in the Central Valley fall numbers build later in the season.

How to recognise it

Adults are olive green above with a gray crown edged in black. A white eyebrow sits between two dark lines, one through the eye and one above the white. The bill is dark.

The iris is red. In adults the red ranges from dull brick to bright crimson, so do not be thrown if the eye looks darker than the name suggests.

Young birds in fall have a brownish iris. It turns red by the end of their first winter, around March. In spring in Costa Rica, second-year birds may still show a brownish tone, and iris color is a reliable age clue only from summer through March.

Immature birds can also show yellow on the flanks and undertail, so check the face first.

What it sounds like

Recording: Christina S. Baer, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It eats insects and spiders taken from foliage, sometimes hanging acrobatically to reach them. It also eats many fruits, such as Trema and Cordia, and arillate seeds.

During migration it forms loose groups, and these may join mixed flocks of resident birds and other migrants. In tropical forests it joins mixed-species feeding flocks and moves through the trees higher up than most of the flock.

Where it lives

It occurs almost anywhere with trees or tall shrubs: canopy, forest edge, secondary growth, suburban gardens and city parks.

It is found mainly in the lowlands and is often common up to about 1300 m in the Central Valley. A few reach at least 2150 m in fall.

It is listed as a passage migrant for the Caribbean lowlands, Tortuguero, Arenal, Guanacaste, Osa, the Pacific Central region, Tempisque, the Central Volcanic range and Isla del Coco.

When to see it

It is an abundant passage migrant in fall, from late August to early November, and passes again in spring, from early April to late May, with April a high time. Stragglers can be a month late either way, and along the Caribbean coast they have been regularly recorded into late November.

Similar birds

The Yellow-green Vireo also has a red iris, so the two are easily confused. Red-eyed shows a dark line through the eye that fully outlines the white eyebrow, plus black edging on the gray crown, and Yellow-green lacks these. Yellow-green has a less bold eyebrow and much more yellow on the sides and flanks. Yellow-green is here from about late January to late October, while Red-eyed is only a passage migrant. The resident Chivi Vireo was once treated as the same species, so compare the two. Black-whiskered Vireo is a rare vagrant, so in October check Red-eyed flocks for a dark malar stripe.

Names and lore in Costa Rica

Costa Rica's standard Spanish name is vireo ojirrojo, and it is also known as Chiguisa. Elsewhere you may hear verderón ojirrojo in Colombia and vireo de ojo rojo in Cuba and the Dominican Republic.

Status and conservation

It is listed as a migrant (M) on the AOCR list, and the IUCN does not consider it threatened.

Photography tips

Scan higher in the trees, where it feeds above most of the flock, and give mixed flocks at forest edges and gardens a slow look.