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TENNESSEE WARBLER Leiothlypis (Oreothlypis) peregrina 11–12cm. Winter
migrant to varied forest and woodland habitats, especially foothill forest, shade
coffee plantations. Mostly in canopy, often in small flocks at flowering trees.
Face can stain pink from pollen. Note sharp bill, dark eyestripe, whitish under
tail coverts. Fall/winter birds bright greenish above, washed yellow on breast,
often have narrow pale wingbar, adult male crown grayish, tinged olive; spring
adults whiter below, adult male crown blue-gray. SOUNDS: Sharp, high, slightly
smacking chik. STATUS: Fairly common to common Oct–Apr on both slopes,
especially foothills; more widespread in migration, mid-Sep to Nov, Apr–early
May. (Breeds n. N America, winters Mexico to nw. S America.)
BLACK-AND-WHITE WARBLER Mniotilta varia 11.5–12.5cm. Winter
migrant to varied woodland and forest habitats, from mangroves to highland
oak forest. Creeps along trunks and branches like a nuthatch; joins mixed
flocks. Behavior distinctive, plus boldly black-and-white striped back, dark
centers to undertail coverts. Ad. male has black cheeks, attains black throat
Mar–Apr; imm. and female have pale cheeks, variably washed buff on flanks.
SOUNDS: High, slightly liquid spik, at times in fairly rapid spluttering series.
STATUS: Fairly common to uncommon Sep–Mar on both slopes, locally to
2500m; more widespread in migration, late Jul–Oct, Mar–early May. (Breeds
N America, winters Mexico to nw. S America.)
YELLOW-THROATED WARBLER Setophaga dominica 12–13cm. Rare winter migrant to open and
semi-open areas with taller trees (especially coconut palms in coastal lowlands, pines in highlands),
woodland edge; often creeps around balconies and lights, seeking insects. Usually solitary, independent of
flocks. Distinctive, with broad black sideburns, white eyebrow and neck patch, long pointed bill. Ages/
sexes similar but imm. female averages dullest, adult male brightest. SOUNDS: Sharp chik, suggests Yellow
Warbler but averages higher, sharper. STATUS: Rare Aug–Mar on both slopes, mainly on Caribbean slope
and in Central Valley, below 1500m. (Breeds e. N America, winters Mexico to Panama.)
MYRTLE [YELLOW-RUMPED] WARBLER Setophaga coronata 12.5–13.5cm.
Winter migrant to varied open and lightly wooded habitats from scrub and
pastures to dry forest edge, fruiting shrubs. Mainly forages low, often on
ground, but also ranges to canopy; usually independent of mixed flocks. Often
makes fluttering sallies for insects. Note relatively large size, habits, face pattern,
yellow rump (often covered by wings) and variable yellowish patches at sides of
breast; breeding plumage seen rarely in Costa Rica. SOUNDS: Fairly strong sharp
tchek; high sit, mainly in flight. STATUS: Irregular, uncommon to rare Nov–Mar
on both slopes to 1800m; more widespread in migration, Oct–Nov, Mar–early
Apr. (Breeds n. N America, winters US to Cen America.)