Adult Male:
Head, neck, and upper back are grayish-brown. Shoulders are similar to the back, but slightly lighter gray. Lower back and flanks transition to a slightly bluish-gray. Upper tail coverts are white. The foreneck, chest, and belly are pale grayish-brown, occasionally with black markings. The vent and undertail coverts are white. The outer two pairs of tail feathers are white, the central pair is brown with white tips, and the remaining tail feathers transition from white to brown. The flanks are white with pale gray barring. The lesser coverts, the base of the flight feathers, and the primary coverts are pale bluish-gray. The remainder of the wings is brown. Underwing coverts and axillaries are pale bluish-gray.
Adult Female:
Slightly smaller than the male.
Juveniles:
Similar in coloration to adults: head gray, lacking the black markings on the chest. Pale gray flanks. Bill and legs are pale yellow. Eyes are brown. Bill and legs are pale pink.
Measurements:
- Wing (male): 430 – 513 mm
- Wing (female): 395 – 470 mm
- Tail: 126 – 146 mm
- Tarsus: 72 – 82 mm
- Bill: 53 – 70 mm
- Weight: 2.6 – 6 kg
Distribution:
The Greylag Goose nests in Iceland, Northern England, western and southern Scandinavia, and temperate Asia. In winter, it migrates south from the Mediterranean, through Central Asia, India, Myanmar, eastern and southern China, and northern Vietnam.
In Vietnam:
This species is common in the coastal plains (south to Thừa Thiên Province) during the winter.