The Nightingale Reed-warbler is characterized by a horn colored, long and slender bill and overall pale yellowish-buff color (Baker 1951; Pratt et al. 1987). The species is pale yellow-buff below, rufous-brown or grayish olive-brown above, with a pale yellow eyebrow (Baker 1951; Pratt et al. 1987). Head feathers are “shaggy” in appearance and often held erect and the tarsi and feet are light gray (Pratt et al. 1987). Females are similar to the males but are slightly smaller, while immature birds are similar to adults with duller and browner upper-parts and less yellow under-parts (Baker 1951).Juvenile plumage is brown with buff edges, and the breast, belly, vent, thighs, and undertail coverts light yellow to cream, with flanks brownish yellow to buff. Juveniles lack the pale yellow supercilium and black lores that are characteristic of adults. Nightingale Reed-warbler eggs are sub-elliptical in shape, dull white to cream to ivory buff in color. They are spotted, speckled, and blotched with irregular shaped markings over entire shell, typically with overlapping markings around broader end of the egg. The markings are gray, brown, black, and rust in color with pinpoints up to 2.3mm in diameter.