Adult:
- A white ring encircles the eye. The area in front of the eye and the feathers below the eye are black.
- The forehead and crown are yellow. The remainder of the head and the back, including the exposed parts of the wings and tail, are bright yellowish-green.
- The chin, throat, and undertail coverts are pale yellow. The breast and flanks are pale gray. The mid-belly is white. In winter, the belly is more or less tinged with yellowish-brown.
- Eyes are brown. The beak is pale black with a grayish-blue base. Legs are pale blue.
Measurements:
- Wing: 50 – 60 mm
- Tail: 36 – 40 mm
- Tarsus: 15 – 16 mm
- Beak: 10 – 11 mm
Distribution:
- The species is distributed in China and Indochina.
- In Vietnam, it is common throughout the plains and mountainous regions from the northern border to approximately Hai Van Pass in the south. It also occurs on offshore islands such as the Paracel Islands (Hoang Sa Archipelago).