Plain-bellied Watersnake

Scientific Name: Nerodia erythrogaster

Average Length: 30–40 inches (76–102 cm)

Maximum Length: About 60 inches (152 cm)

Status at Snake Road: Common

Venomous? No

Description

The Plain-bellied Watersnake is one of the largest snakes commonly encountered at Snake Road. Adults are typically olive, brown, gray, or nearly black and often become almost completely patternless with age. Unlike most watersnakes, they lack bold dorsal markings as adults, giving them a clean, uniform appearance.

As their name suggests, the most distinctive feature is the underside. The belly is usually an unmarked yellow, cream, orange, or reddish-orange, without the checkerboard or half-moon markings found on other watersnakes. Although the belly is not always visible in the field, it is one of the best identification features when it can be seen.

Like all members of the genus Nerodia, Plain-bellied Watersnakes have strongly keeled scales and a heavy, muscular build.

Behavior

Plain-bellied Watersnakes are powerful swimmers but spend more time away from the water than many other watersnake species. They are frequently seen basking along the road, resting in low vegetation, or traveling between wetlands and the surrounding bluffs during migration.

When approached, they usually retreat quickly. If cornered or handled, they may flatten their body, strike defensively, and release a strong-smelling musk. Despite their intimidating behavior, they are completely harmless to humans.

Their diet consists primarily of frogs, salamanders, fish, and occasionally crayfish.

Habitat

At Snake Road, Plain-bellied Watersnakes are found throughout the wetlands, drainage ditches, flooded woods, and nearby forest edges. They are particularly common in areas where shallow water meets dense vegetation but are also regularly encountered well away from water during seasonal movements.

Where You're Most Likely to See One

Plain-bellied Watersnakes can be encountered nearly anywhere along Snake Road, though they are especially common near the swamp, roadside ditches, and wooded edges adjacent to wetlands. During migration, they are often seen crossing the pavement in broad daylight, making them one of the more frequently observed large snakes.

Commonly Confused With

Diamond-backed Watersnake (Nerodia rhombifer)

These two heavy-bodied watersnakes are commonly found in the same habitats. Adult Diamond-backed Watersnakes usually retain at least a faint diamond or chain-like pattern across the back, while Plain-bellied Watersnakes are often nearly patternless. If the underside is visible, Plain-bellied Watersnakes have a mostly solid yellow, orange, or cream-colored belly, whereas Diamond-backed Watersnakes have dark checkerboard or half-moon markings.

Mississippi Green Watersnake (Nerodia cyclopion)

Older Mississippi Green Watersnakes may also appear uniformly olive or brown, making them easy to mistake for Plain-bellied Watersnakes. Mississippi Greens typically have more noticeable dark bars on the lips, larger eyes positioned higher on the head, and often retain faint body markings. The plain, unmarked belly of the Plain-bellied Watersnake remains one of the best characteristics for separating the two species.

Fun Fact

Unlike most watersnakes, Plain-bellied Watersnakes regularly forage well away from water. It is not unusual to find one traveling through the forest or crossing dry ground in search of frogs, salamanders, or new wetlands, making them one of the most terrestrial members of the Nerodia genus.