The Plain-bellied water snake is a nonvenomous snake native to the United States. This species gets its common name because it has no patterning on its underside. These snakes can vary in color from brown to gray, to olive green, with dark-colored blotching down the back, and an underside that is yellow, brown, red, or green.
Plain-bellied water snakes range through much of the southeastern United States, from Michigan to Delaware in the north, and Texas to northern Florida in the south, but they are absent from the Florida peninsula and the higher elevations of the Appalachian Mountains. These snakes are almost always found near a permanent water source, such as lakes, streams, ponds, bogs, shrubby swamps, or marshes.
Plain-bellied water snakes are semi-aquatic reptiles and lead a solitary life. They are active during the day and often bask or rest in vegetation near water or hang on branches above the water. This also helps them to escape danger by quickly dropping in water. These snakes do come out on land, especially during warm days and usually hibernate in crayfish burrows near wetlands, underground or under rock piles. Plain-belied water snakes are excellent swimmers; they hunt mainly in the water and can travel long distances to reach their prey. Although these snakes are not-venomous, they are quick to vigorously defend themselves when threatened by striking repeatedly and flattening their head. They may also release a foul-smelling musk.
Plain-bellied water snakes are polyandrous meaning that females mate with multiple males each breeding season. They breed from April to June, and broods of 5-27 live young are born in August to October. The gestation period lasts 4 to 7 months. Newly born baby snakes measure 19-33 cm (7.5-13 in) at birth; they are completely independent and don't receive parental care. Both males and females become reproductively mature when they are 3 to 4 years old.
Locally, some populations of Plain-bellied water snakes suffer from the loss of their habitat and road mortality.
According to IUCN, the Plain-bellied water snake is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Due to their diet habits, Plain-bellied water snakes help keep prey populations in balance. In turn, they are an important food source for many local predators.