Plain-bellied Watersnake (Nerodia erythrogaster ssp.)
The general coloration of the Plain-bellied Watersnake can be brown, green, or gray. In Arkansas, the belly color is a plain yellow or cream. Like other nonvenomous watersnakes, it has several dark, vertical lines that outline the upper lip scales. The scales are strongly keeled and the anal plate is divided.
Two subspecies, the Yellow-bellied Watersnake (N. e. flavigaster) and Blotched Watersnake (N. e. transversa), occur in the state. Adults of the Yellow-bellied subspecies usually have a plain-colored back, whereas adults of the Blotched subspecies usually retain more of a juvenile patterning into adulthood. Patterned adults have a series of faint, light colored crossbars bordered in black that run along the backbone. The intergrade zone between these two subspecies in Arkansas is not clearly established.
Juveniles of this species closely resemble that of the Midland Watersnake. A subtle difference can be seen in the patterning near the neck. In juveniles of the Plain-bellied Watersnake, the neck blotches are broken to create a checkered pattern. In the Midland Watersnake, the neck blotches form complete bands. Identification can be confirmed by examining the belly, which is plain in the Plain-bellied Watersnake.
All of the species of watersnakes that occur in Arkansas look similar and it does take some practice to tell them apart (even from the venomous Cottonmouth!). Refer to each species account to learn the subtle differences.
This species can be found living concurrently with other species of watersnakes in and around lakes, ponds, streams, rivers, and drainage ditches. It seems to be more at home in still waters. Due to its behavior, it prefers trees along the edges of waters.
This species can be observed during daylight hours basking along the banks of water. It is known to bask in branches and vines overhanging the water. (Cottonmouth are not known to exhibit this same tree-basking behavior.) It will quickly drop into the water if threatened; sometimes finding itself in a fisherman's boat! Although this species may occasionally forage during the day, it is usually more active at night. The seasonal activity of this species correlates with the temperature of water and, to a lesser extent, ambient temperature. When the water and ambient temperatures reach their highs in late summer, this is also when you can expect the most activity from watersnakes. It is not uncommon to find this species crossing roads after rainfall.
This species breeds in early spring. In late summer or early fall, females will give birth to live young.
This species preys primarily upon frogs. Small fish make up most of the remaining portion of the diet.
This species relies upon its stealth and ability to remain submerged for long periods of time to catch its prey. It will actively search through underwater rock crevices and vegetation for its prey, lunging after what it can grasp. A successful bite usually hooks the fin of a fish or foot of a frog. Larger prey is dragged out of the water and eaten on the bank. If, after the prey has stopped struggling, the snake decides to seek out the head--it goes down easier!--a carefully timed flop or jump can leave the snake without a meal. This species has been observed hanging from a tree with its head in the water and catching fish that would swim by.
When first approached, this species will try to flee with great haste. It may dive under the water, hide under a rock, or dart into a hole near the water's edge. It will go to great lengths to avoid conflict with humans.
If it is unable to escape, it will defend itself by flattening its head, hissing, biting, releasing a foul-smelling musk. I find the musk of watersnakes more "foul" than most other snakes. Due to its aggressive defensive behavior, it is commonly mistaken for the venomous Cottonmouth.
Many people mistake this species for a Cottonmouth and kill it on sight. This is especially true at rural farm ponds and fish farms where people "protect" their fish stock. Despite persecution, populations of this species appear secure.