How to Identify the Velvety Green Night Adder (Identification Guide)

Key identifying features

The Velvety Green Night Adder (Causus resimus) stands out among night adders for its smooth, glossy, almost velvet-textured green scales, a marked contrast to the rougher-scaled vipers found elsewhere in Africa. Its stout body, rounded head, and uniform bright green color make it one of the more visually distinctive members of the night adder group.

Coloration & pattern

This species is typically a vivid, uniform grass-green to bluish-green along the back, often without strong patterning, giving it a smooth, almost unmarked appearance. Some individuals show faint darker speckling or a subtle vertebral line, but the overall impression is of a plain, richly colored green snake. The belly is usually pale yellow-green to whitish, contrasting with the brighter dorsal color.

Head, eyes & scales

The head is only moderately distinct from the neck compared to typical vipers, being more rounded and less strongly triangular, and often marked with a dark, V-shaped or chevron marking on top. Eyes are relatively large and round-pupiled for a viperid, an unusual trait among Causus species. Body scales are smooth or only weakly keeled, giving the skin a soft, glossy, velvety texture rather than the rough feel typical of true bush vipers.

Size & body shape

This is a small-to-medium snake, typically reaching 40-60 cm (16-24 inches), occasionally longer. The body is moderately stout and cylindrical rather than laterally compressed, since this species is largely terrestrial rather than arboreal, and the tail is short and non-prehensile.

Range & habitat where you'll see it

The Velvety Green Night Adder ranges across parts of East and Central Africa, including South Sudan, Uganda, Kenya, and Ethiopia, favoring moist savanna, grassland, and marshy edges near water. Unlike the climbing Atheris bush vipers, it is a ground-dwelling species often found near swamps, streams, and damp grassy areas, since its diet centers on amphibians.

How to tell it apart from look-alikes

Its smooth or barely keeled, glossy green scales distinguish it clearly from rough-scaled Atheris bush vipers, which live in similar African forest and shrub habitats but have strongly keeled, textured scales. Compared to other Causus species like the Rhombic Night Adder, which shows a bold dark rhombic pattern, the Velvety Green Night Adder is comparatively plain and uniformly green, with the dark head chevron being one of its few consistent markings.