How to Identify the White-lipped Keelback (Identification Guide)

Key identifying features

As the name suggests, the White-lipped Keelback's most distinctive feature is a pale, often bright white or cream stripe running along the upper lip (supralabial scales), sharply contrasting with a darker head and body. This clean facial stripe, combined with rough keeled dorsal scales, is the quickest way to identify this semi-aquatic colubrid in the field.

Coloration & pattern

The dorsal body color ranges from dark olive to blackish-brown or deep gray, sometimes with a faint pattern of darker crossbars or speckling that is difficult to see against the dark background. Some individuals show a subtle greenish or bronze sheen in good light. The most eye-catching pattern element remains the crisp white or pale yellow lip line that traces the edge of the jaw from behind the eye toward the snout, standing out clearly against the darker head color.

Head, eyes & scales

The head is moderately distinct from the neck and typically as dark as or darker than the body, making the white lip stripe especially conspicuous. Eyes are of moderate size with round pupils. Dorsal scales are keeled in longitudinal rows, producing a slightly rough texture, and the anal scale and subcaudals follow typical natricine keelback arrangement. The keeling tends to be most obvious toward the rear half of the body.

Size & body shape

This is a small to medium-sized snake, with adults commonly measuring between roughly 30 and 60 cm in total length, occasionally longer. The body is slender and cylindrical, with a moderately long tail, built for moving through wet vegetation and shallow water rather than aquatic swimming in open water.

Range & habitat where you'll see it

The White-lipped Keelback favors damp lowland habitats including marshes, flooded grassland, pond edges, and slow streams, often in disturbed or agricultural landscapes such as rice paddies. It is typically active during the day and is frequently found hunting frogs and small aquatic prey at the water's edge.

How to tell it apart from look-alikes

While several keelbacks and natricine snakes occur in similar wetland habitats, the combination of an overall dark body color with a sharply defined pale lip stripe is comparatively distinctive. Species with striped or blotched dorsal patterns, such as the buff-striped keelback, differ by having a pale vertebral line rather than relying on facial contrast. Checkered keelbacks show a bold checkerboard dorsal pattern instead of a uniform dark body. When the lip stripe is faded or the snake is viewed only briefly, checking the keeled scale texture and dark, unmarked dorsum in combination with any visible facial contrast is the best way to confirm identification.