Tennessee Warbler

How to find it

Check flowering trees, shaded coffee farms and fruit feeders first. It is typically a canopy bird in winter, so look in treetops, second growth and gardens. It tends to travel in small groups with other birds, so go through mixed flocks with honeycreepers, greenlets and other warblers. Late in the dry season many birds climb to at least 3000 m in mountain forests, when oaks bloom and new leaves sprout. During migration it can turn up almost anywhere.

How to recognise it

Think small, plain and constantly moving. It is a sparrow-sized warbler, and winter birds are gray and green-yellow.

They feed in constant motion, so a good view can be brief. Birds seen on a January trip were still in non-breeding plumage, so expect the subdued winter look.

Three marks help:

- a small, sharp, needle-fine bill

- bright white undertail feathers, even when the rest of the underparts look yellowish

- no olive-brown back or dark cap, which Philadelphia Vireo shows in this plumage

In Guanacaste in the dry season, these warblers often have faces stained orange from Combretum pollen, a vivid sign they have been feeding at flowers.

What it sounds like

Recording: Donald Davesne, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

This is a restless forager. In Costa Rica it feeds from the undergrowth up to the canopy, in brushy areas and in mixed flocks. Across its range it forages nervously and quickly, creeps along branches and is found at all levels.

On its wintering grounds it takes nectar and larvae from flowering trees, and it sometimes visits hummingbird feeders and banana fruit feeders. It also visits coffee farms with shade trees, especially trees in flower. At Monteverde it was described as the species with the most flexible diet, using a wide range of foods in winter.

Where it lives

In Costa Rica this warbler winters mostly on the drier Pacific slope and at higher elevations. It also occurs on the Caribbean slope, but it is less common there.

A Costa Rican natural history account calls it common to abundant in winter from sea level to about 2300 m on both slopes. It is more common at middle elevations than in the lowlands, and very abundant in the Central Valley.

In winter it prefers partly open second growth, coffee farms and gardens, and you can expect it in dry forest and many edge habitats. It is regular in the canopy and at forest edges.

When to see it

Birds usually arrive between mid and late September, with big waves from mid October through November, and the wintering season runs to March. Spring migration passes through Costa Rica in April and early May.

Similar birds

Orange-crowned Warbler is the main lookalike. It has a weaker eyeline and yellower feathers under the tail, while Tennessee has whiter undertail feathers. A quick glimpse can also be confused with a Philadelphia Vireo, which has a thicker bill, a bigger head and a wider eyebrow and eyeline. Red-eyed and Warbling Vireos have thicker hooked bills and a stronger pale eyebrow, and a needle-fine bill rules out any vireo.

Names and lore in Costa Rica

The Costa Rican list name is Reinita Verdilla. Local nicknames are Cazadorcita ('little hunter') and, in some lists, Choricilla.

Status and conservation

The AOCR list marks it as a migrant (M), and the IUCN rates it Least Concern because its breeding range is very wide, it adapts to disturbed areas and its population looks stable.

Photography tips

Flowering trees and fruit feeders hold still-ish birds better than open branches. Try shaded coffee farms with trees in bloom, where it feeds in constant motion at nectar.