Sick's Swift

Small leaf warbler with many extremely similar relatives. Like other “Pallas’s-type” leaf warblers, has olive-yellow upperparts, pale underparts, prominent brow and crown stripes, double wingbars, and a pale rump. Unlike Ashy-throated and Buff-barred Warblers, lacks any white on outer tail edges. Pallas’s averages yellower-headed and brighter overall. Gansu and Chinese Leaf Warblers can be incredibly similar, but Lemon-rumped averages whiter-browed and yellower-bellied than the former, more contrastingly-marked on the head than the latter, and darker-billed than both. As with many other physically similar leaf warblers, best distinguished by voice and habitat. Breeds in coniferous and mixed forests at mid- to high-elevation forests, though may descend into foothills in the winter. Two song types are both highly distinctive; one is a buzzy, descending rattling trill and the other is a series of high-pitched clicking twitters. Call is a loud, strident pair of notes: “pse-tew!”

Spectacular male shows diagnostic maroon sides to head and collar, iridescent metallic blue-green forehead and crown, blue shoulder, moss-green back, and yellow rump. Underside is uniform bright yellow in both sexes, although female is entirely olive above. Juvenile resembles female but with pale legs. Singles and pairs inhabit forest, shrubbery, and plantations in lowlands and lower hills, often joining mixed-species flocks. Female can be separated from female Black and Brown-throated Sunbirds by bright yellow underparts and lack of yellow eyebrow. Gives high-pitched “tzeeet” calls. Song is an undulating trill.

Slender, long-winged plover usually found in relatively dry habitats. Breeding plumage shows black belly and face, white neck sides, and dark back and crown spangled with gold. Note sides and undertail coverts entirely black, but beware females and molting birds can be mottled with some white. Nonbreeding plumage is much drabber; grayish overall with distinct white eyebrow and dark cap. Juveniles are crisp and neatly spangled above, washed with gold on the upperparts. At all seasons, note slender shape and narrow bill to separate from Black-bellied Plover, along with grayish underwing in flight. Extremely similar to Pacific Golden-Plover; American is slightly longer-winged, shorter-legged, and smaller-billed, but these features are difficult to judge. Juvenile American is usually duller than Pacific, especially on the face and neck. Average habitat preferences are important (Pacific Golden and Black-bellied more regular on beaches and mudflats), but much overlap. Range is also important. Breeds on Arctic tundra. Fairly common migrant through central North America, uncommon on East Coast, rare on Pacific Coast. During migration, prefers sod fields, dry mudflats, and pastures; often in small flocks, sometimes mixed with Black-bellied Plover. Winters in South America. Note voice: a plaintive “pleedoo” call.