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YELLOW-GREEN VIREO  Vireo flavoviridis 14–15cm. Common summer

migrant to varied forested and wooded habitats from gallery forest and

plantations to dry forest, gardens, mangroves; generally not in dense and wetter

forests. Mainly at upper levels in leafy foliage, coming lower to feed at edges and

in fruiting shrubs. Sings tirelessly from canopy; often cocks tail, and raises

crown when agitated. Fairly distinctive, with more diffuse face pattern than

Red-eyed Vireo, bright yellowish neck sides and flanks, bigger bill. Juv. has dark

eyes, duller overall. SOUNDS: Gruff downslurred mewing miehh and soft dry

chatter. Song of varied, burry to slightly nasal chirps given in leisurely, often

hesitant manner, ch-ree, chree, swi ch-ree, chree..., repeated tirelessly; suggests a House Sparrow that’s taken

singing lessons. STATUS: Common to fairly common Feb–Sep on Pacific slope, uncommon on Caribbean

slope, to 1500m; more widespread in migration, late Jan–Mar, Sep–Oct. (Breeds Mexico to S America,

winters S America.)

RED-EYED VIREO  Vireo olivaceus 14–15cm. Transient migrant in varied

wooded and forested habitats, second growth, scrub. Forages low to high, mainly

in canopy and at fruiting trees and shrubs. Note distinctive face pattern, with

neat, thin dark line between broad whitish eyebrow and blue-gray crown;

underparts silky whitish overall, with pale yellowish undertail coverts; flanks

rarely tinged pale yellow on some fall birds. Cf. Yellow-green Vireo. Imm. has

brown eyes. SOUNDS: Mostly silent in migration; rough, downslurred mewing

rrieh, averages more drawn-out, rougher than Yellow-green Vireo. STATUS: Fairly

common to common mid-Aug to Nov, Mar–May; commonest in lowlands and

foothills. (Breeds N America, winters S America.)

*SOUTHERN BROWN-CAPPED VIREO  Vireo leucophrys 11–12cm. Humid

highland forest, adjacent second growth and pastures with taller trees. Mainly

at mid–upper levels, often probing in leafy foliage and at fruiting trees; joins

mixed flocks of warblers, other vireos, bush-tanagers. Note broad pale eyebrow,

contrast between whitish throat and pale yellow underparts, brown crown and

back. Cf. migrant Philadelphia Vireo. Juv. has duller face pattern, paler under­

parts, soon like adult. SOUNDS: High, shrill, slightly hissing, over­slurred ssíih,

recalling a Tolmomyias flatbill. Song a rambling, rather even-paced short warble,

1.5–2 secs, every 6–15 or so secs; slower-paced and mellower than North

American warbling vireos. STATUS: Fairly common on both slopes, 1500–2400m; lower locally in fall after

breeding, to 1200m. (Costa Rica to S America.)

PHILADELPHIA VIREO  Vireo philadelphicus 11–12cm. Rather small, compact

migrant vireo of varied wooded and forested habitats, plantations, second

growth. Mainly at mid–upper levels; often joins mixed flocks and visits fruiting

trees. Note variable yellow wash to throat and breast (some birds extensively

yellowish below), relatively small bill, dark lores (prominence of which varies

with angle of viewing). Cf. Tennessee Warbler. SOUNDS: Low gruff cheh, often in

short series or repeated steadily. STATUS: Uncommon to fairly common Oct–Apr

on both slopes, locally to 2100m; more widespread in migration, Sep–Oct, Apr–

early May. (Breeds N America, winters Mexico to Panama.)

*EASTERN WARBLING VIREO  Vireo gilvus 12–13cm. Rare winter migrant to wooded and forested

habitats, hedgerows, second growth. Forages low to high, often with mixed flocks of warblers, other

vireos, and at fruiting trees. Note broad pale eyebrow, overall drab plumage. Faded Philadelphia Vireo

often mistaken for Eastern Warbling but smaller and more compact, with rounder head, smaller bill,

brighter yellow wash on throat and breast, darker lores; also cf. Red-eyed Vireo, which has stronger face

pattern, bigger bill, longer wings, shorter tail. SOUNDS: Slurred nasal nyeih, at times repeated insistently

when scolding, buzzier and less mewing than Red-eyed Vireo. STATUS: Very rare Oct–Apr; reported on

both slopes but not annual, should be documented carefully. (Breeds N America, winters Mexico to

Nicaragua, rarely to Costa Rica.)