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*BLUE-AND-WHITE SWALLOW  Pygochelidon cyanoleuca 11.5–13.5cm.

Common and widespread swallow of highlands and foothills; ranges from cities

and farmland to páramo and forest; nests in holes in banks, buildings, hollow

trees. Locally in flocks, regularly gathering on wires with other swallows. Flight

quick and ‘twinkling’ with brief glides, at times soaring high overhead. Note

black undertail coverts, deeply forked tail. Juv. brownish above with variable

dusky wash across breast, shallower tail fork. Comprises 2 groups that may

represent species: smaller resident Mountain Swallow P. [c.] cyanoleuca (11.5–

12.5cm) with blackish underwing coverts, more extensive black on undertail

coverts, Jun–Oct wing molt; and larger austral migrant Patagonian Swallow P. [c.] patagonica (12.5–

13.5cm) with dusky whitish underwing coverts, slightly deeper tail fork, Mar–Jul wing molt.

SOUNDS: Mountain has downslurred, high burry tzzih and tssiu; varied, high and often rather buzzy

chipping and twittering; Patagonian a lower buzzy dzzzhir and zzhie. STATUS: Mountain is common to

fairly common resident, mainly above 500m, rarely lower. Patagonian is austral nonbr. migrant Apr–Aug

n. regularly to Panama, likely overlooked in Costa Rica; any birds in lowlands should be checked. (Costa

Rica to S America.)

VIOLET-GREEN SWALLOW  Tachycineta thalassina 11.5–12.5cm. Rather compact, short-tailed migrant

swallow found as singles or small flocks that associate with other swallows. Flight rather quick and

‘twinkling,’ often fairly high overhead. Note white ‘saddlebags’ (rarely can appear white-rumped), short tail

(at rest, wing-tips project past tail tip; cf. larger, longer-tailed Tree Swallow), face pattern. SOUNDS: High

chipping chi-chit and variations, higher and drier than Tree Swallow, less burry than Mangrove Swallow.

STATUS: Scarce and irregular Oct–Mar, mainly in nw. lowlands, also rarely in highlands. (Breeds w. N

America and Mexico, winters Mexico to Costa Rica.)

TREE SWALLOW  Tachycineta bicolor 13.5–14.5cm. Rather chunky migrant swallow of varied open

habitats, often near water; singles or small groups often with other swallows. Flight fairly powerful, often

direct, recalling martins rather than smaller, more ‘twinkling’ Violet-green and Mangrove Swallows. Note

notched tail, white underparts, face pattern. 1st-year female dusky gray-brown above with dingy breast

band; male and adult female metallic greenish blue above. SOUNDS: Chirping chrit and chri-chii, lower,

more liquid than Mangrove Swallow. STATUS: Scarce and irregular Nov–Apr in nw. lowlands; could occur

anywhere, mainly below 1500m. (Breeds N America, winters s. US to Panama.)

MANGROVE SWALLOW  Tachycineta albilinea 11–12cm. Small spritely

swallow never far from water, from mangroves and coastal lagoons to larger

rivers well inland; nests in cavities in dead trees, rocks, buildings. Flight fast and

twinkling, often low over water; perches on sticks and rocks in water, and with

other swallows on wires. White rump diagnostic; also note white underwing

coverts (dark on Tree and Violet-green Swallows), small white forehead chevron.

Juv. dusky gray-brown above, attains adult plumage by winter. SOUNDS: High

chipping chrrit and chiri-chrit, at times buzzier notes. Song a varied series of

chirps and burry chips. STATUS: Fairly common to common on both slopes,

locally to 1000m. (Mexico to Panama.)

BANK SWALLOW (SAND MARTIN)  Riparia riparia 11.5–12.5cm. Small,

rather compact migrant swallow of varied open habitats, commonly near water;

often with other swallows feeding over water, resting on wires. Distinctive: note

small size, cleft tail, white throat and neck sides offset by brown breast band. Cf.

imm. Tree Swallow, rough-winged swallows. SOUNDS: Rolled gravelly zzzr, often

doubled; drier and buzzier than rough-winged swallows. STATUS: Sporadically

common mid-Aug to Nov, Mar to mid-May, in lowlands, locally to 1500m;

uncommon to scarce and local in winter. (Breeds Holarctic; winters Mexico to

S America.)