Plain-bellied Watersnake

Nerodia erythrogaster, also known as the plain-bellied water snake or plainbelly water snake, is a common species of semi-aquatic, non-venomous colubrid snake endemic to the United States.

Description

The plain-bellied water snake is a large, thick-bodied, mostly patternless snake, with a generally beige underside. Some snakes display a thin, white line between the pale belly and their darker top scales. Subspecies can range from dark brown, gray, and olive-green to greenish-gray or blackish in color. Some lighter-colored individuals have dark dorsal patterns. Plain-bellied water snakes can be distinguished from other water snakes by their "plain", patternless undersides, which vary in color from light reddish hues to beige; this is where they get the common name "plain-bellied", as they typically have no notable markings on their bellies. There used to be recognized subspecies of the plain-bellied water snake, although scientists often had a hard time differentiating between them. This has led to these subspecies no longer being recognized.

The scientific name erythrogaster comes from the Greek word "erythros" (meaning 'red') and "gaster" (meaning 'belly'). This species exhibits geographically-distinct, phenotypic variations which result in a number of unique subspecies. Adults vary in size from 24 to 40 inches (76–122 cm) in total length. Juvenile snakes feature patterns similar to banded water snakes, but can be identified by their unmarked bellies.

Distribution and habitat

Plain-bellied water snakes are found in every southeastern state of the U.S., except for the higher elevations in the Appalachian Mountains (thus excluding them from eastern Tennessee and western North Carolina). On the east coast, they are found across Florida, north to southeastern Virginia, as well as western Tennessee. They are found at lower elevations from Georgia and west across the Gulf States, extending as far west as Oklahoma and Texas. The snakes are almost always found near a permanent freshwater source, usually several feet deep, and not necessarily clear or fast-moving waters, either. They can often be observed resting on branches or foliage directly over the water, for an easy escape route. In their natural geographic range, the snakes are adapted to a wetland lifestyle, often found at or near creeks, rivers, swamps, floodplains, lakes, and ponds, as well as man-made reservoirs, dams, and canals.

Behavior and diet

Plain-bellied water snakes are active in the warmest months of the year. During the hottest months of summer, they will be active both during the day and at night. In warmer months, they are typically found basking on logs or near bodies of water, swimming, or traveling over land. During hot, humid weather, they will travel long distances away from water. Nerodia erythrogaster is found no further than (approximately) 318 feet (97 m) away from a freshwater source, but do travel over dry land, around 98–108 feet (30–33 m) in a single day. Unfortunately, their migration leads to high mortality rates on roads, with mortality rates reaching up to sixty percent. They tend to spend more time in terrestrial habitats than other species of Nerodia. They hibernate during the coldest months of the winter.