The nukupu‘u (Maui nukupuu): (14 cm. Medium-sized honeycreeper with strongly downcurved "heterobill" in which mandible is half the length of maxilla. Kaua`i male golden-yellow on head and breast, shading to white on belly and undertail-coverts. Crown, nape, postocular line and posterior edge of ear-coverts slightly tinged greenish, yellowish-green upper-parts. Black lores, eye-ring, and bill. Kaua`i female greenish-grey above, mostly dull white below with yellow restricted to chin, upper throat, and supraloral patch. Maui male similar except greyer dorsally, darker on crown and nape, yellower on belly and undertail. Maui female similar but duller, more dark colouring on head producing prominent yellow superciliary.