How to Identify the Red-necked Keelback (Identification Guide)

Key identifying features

The red-necked keelback (Rhabdophis subminiatus) is identified by its bright green to olive-green body, black crossbars or speckling near the front of the body, and a vivid orange-red to reddish patch on the neck just behind the head, which gives the species its name. This colorful neck patch, most vivid in younger individuals, is the standout field mark.

Coloration & pattern

The body is bright green to olive-green, becoming more uniformly greenish or brownish toward the tail. Just behind the head, a bold orange-red to crimson patch covers the neck region, sometimes extending onto the front third of the body as scattered black-edged scales or crossbars. This coloration can fade somewhat in older adults but is usually still detectable. The belly is pale greenish-yellow.

Head, eyes & scales

The head is moderately broad and distinct from the neck, green with darker markings sometimes present around the eyes. Eyes are moderate to large with round pupils. Scales are strongly keeled, producing a rough, ridged texture typical of keelback snakes, and often catch light with a slightly dull, matte sheen.

Size & body shape

Adults typically range from 70 to 100 cm (28 to 39 inches), occasionally longer, with a moderately slender, elongated body and a long, tapering tail.

Range & habitat where you'll see it

This species is found across South and Southeast Asia, including parts of India, Bangladesh, Myanmar, Thailand, southern China, and Indonesia, inhabiting rice paddies, grasslands, gardens, and areas near ponds and streams. It is diurnal and semi-aquatic, often found near water where it hunts frogs and toads, and is relatively commonly encountered in agricultural and suburban areas within its range.

How to tell it apart from look-alikes

The closely related red-sided keelback shows red coloration along the sides of the body rather than concentrated on the neck. Green vine snakes are much more slender with a pointed snout and lack the red neck patch. Other green colubrids in the region generally lack both the keeled scales and the distinctive red neck marking. The bright red or orange neck patch on an otherwise green, rough-scaled body is the most reliable way to identify this species.