Banded water snakes ( Nerodia fasciata) are non-venomous snakes commonly found in aquatic environments. They are known for their distinctive markings and adaptable nature. This article delves into the specifics of their appearance, habitat, diet, and behavior, also providing insights into their conservation status and care as pets.
Physical Description
Banded water snakes are heavy-bodied aquatic snakes characterized by a series of irregular, wide, and dark bands across a background of cream coloration. Typically, 13 to 17 of these bands are present. Along the top of the body, the dark bands are separated by 3-4 scales of lighter coloration. In some individuals, the bands are so broad that the lighter background coloration is confined to very narrow bands. The side and underside of the head and neck are usually yellow or cream-colored. The belly is light colored with rectangular belly markings that are reddish, tan, or light brown. Sometimes these rectangles are clustered in sets of two, three, or four.
The scales on the dorsal surfaces of the body are heavily keeled. The pupil of the eye is round, and there are no facial pits between the eye and the rostral, as in pit vipers. These snakes can be easily distinguished from plain-bellied and diamondback water snakes by the combination of broad bands on the body and rectangular markings on the ventral surface.
Adult Southern Watersnakes are typically about 22-42 inches (56-107 cm) in total length. These are stout-bodied snakes with broad black, brown, or red crossbands (often bordered with black) down the back. The lighter narrower bands are tan, gray, or reddish. The light bands may be broken by a black strip down the middle of the back. The crossbands may be obscured as the snake darkens with age, and older individuals may become uniformly black. The background color may be gray, yellow, tan, or reddish. A dark stripe extends from the eye to the angle of the jaw.
Large adult broad-banded water snakes can reach more than four feet in total length.
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Coloration is variable: individuals may be light brown, reddish, or nearly black, with darker crossbands that are broad across the back and narrower along the sides. Unlike the hourglass-shaped bands of the copperhead (Agkistrodon contortrix), these bands are more rectangular. Older snakes often darken, with the pattern becoming faint or obscured, and some appear almost uniformly dark.
Habitat and Distribution
Broad-banded water snakes occur in aquatic habitats across southeastern Oklahoma, reaching the central-southern part of the state along the Red River drainage. They can be found in nearly every imaginable aquatic environment, including streams, swamps, rivers, ponds, lakes, and roadside ditches.
Nerodia fasciata is natively found from southern Illinois, south to Louisiana, and east to North Carolina and Florida. Introduced populations exist in Texas and California; other sources include eastern Texas in its natural range. In 1992, its congener Nerodia sipedon (northern or common water snake) and it were found in three sites in California by the US Fish and Wildlife Service (USFWS). In 2009, more than 300 banded water snakes were caught in suburbs of Los Angeles by the Nerodia Working Group of USFWS. Then in May 2016, the species was found in the Colorado River basin near Yuma, Arizona.
Southern Watersnakes are found throughout mainland Florida in every county.
Coastal Plain from southwest Alabama to North Carolina. In our region, banded watersnakes are restricted to the Coastal Plain, where they are replaced by the closely related northern watersnake (Nerodia sipedon) in the Piedmont and mountain regions.
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The Banded Watersnake resides throughout the coastal plain of South Carolina. They can be found in practically every freshwater wetland system in the Lowcountry, from major rivers and lakes, to expansive blackwater swamps, to ephemeral pools and suburban drainage ditches. They are our most abundant Watersnake here on the Sea Islands.
Diet and Feeding Habits
Most feeding occurs at night, and the diet is dominated by fish. They capture fish by holding their mouths open underwater while moving their heads back and forth. They are capable of quick sideways head motions allowing them to capture fish. Nevertheless, broad-banded water snakes eat a wide variety of prey, including amphibians and the occasional bird.
Banded water snakes feed on a variety of prey including fish, frogs, tadpoles, and salamanders.
The species preys mainly on fish and frogs. On occasion, they prey on small turtles, small snakes, birds, earthworms, and crawfish. Juveniles mainly consume fish and shift towards eating frogs as adults.
Being as widespread as they are, the Banded Watersnake’s diet is equally diverse but, like our other Watersnakes, consists primarily of frogs and fish.
Read also: What to Feed a Chinese Water Dragon
Behavior and Habits
Like other water snakes, they frequently bask on vegetation that overhangs water, dropping silently into the water when approached. The activity season is extended, from March through October. Broad-banded water snakes often bask on vegetation overhanging water or on surface objects in water. They can be approached rather easily by boat. At night, they can be observed by searching along the edges of streams, swamps, ponds, and lakes where they are usually observed in shallow water.
Banded water snakes are frequently observed near aquatic habitats and are active both day and night. They bask on logs or branches overhanging the water and forage in the shallows, feeding primarily on fish and amphibians.
Watersnakes, as the name implies, are a genus of aquatic snakes that spend their days in the swamps, rivers, ponds, and bays of the Carolinas hunting fish, frogs, salamanders, and aquatic invertebrates. During the day they can most easily be found sunning or lounging on stumps, fallen logs, shrubs, culverts, rocks, and banks in or along wetlands. Often they are more active at night, hunting croaking frogs and sluggish fish under the cover of darkness.
Reproduction
Females reach sexual maturity at a size of just over 21 inches. Mating occurs in spring. Similar to other water snakes, broad-banded water snakes are live-bearing, and large females can produce many offspring.
The species is ovoviviparous, giving birth to live young. The brood size varies from 15 to 20 young born in late July or August. Newborns are 200-240 mm (about 8.0-9.5 in) in total length.
Conservation Status
The banded water snake remains common throughout much of its range.
Identification and Mimicry
These snakes can be easily distinguished from plain-bellied and diamondback water snakes by the combination of broad bands on the body and rectangular markings on the ventral surface. A dark stripe extends from the eye to the angle of the jaw.
When threatened, banded water snakes flatten their bodies to appear bigger, emit a foul musk from their anal glands, and bite repeatedly.
Watersnakes mimic the venomous Cottonmouth (Agkistrodon piscivorus) when threatened. They flatten their heads into a broad triangle to resemble a Viper and coil their bodies into a threatening posture. Their keeled scales, a trait they share with our Vipers, help them complete their menacing look. Yet, if you look closely, they lack the vertical “cat’s eye” pupils of a Viper. If approached or touched Watersnakes generally bite without hesitation. This is all just a bluff to convince you to let them be. The Banded Watersnake is a particularly good mimic as it is the same size, body shape, and a similar color and pattern to the Cottonmouth, with which it overlaps in range and habitat.
If the head is viewed from above, the eyes of cottonmouths cannot be seen while the eyes of watersnakes are visible. Cottonmouths have vertically elliptical (cat-like) pupils, whereas watersnakes have round pupils.
Banded Water Snakes as Pets
Water snakes make excellent pets for beginner hobbyists because they are small, active during the day, and do not constrict. They are known for their easygoing personalities. On occasion, snakes may mistake human hands as a food source. All reptiles are potential carriers of infectious diseases, including Salmonella bacteria, which is zoonotic (transmittable to people).
Housing
Water snakes are active reptiles that need plenty of space to explore, hide, and exercise. A single water snake should be housed in at least a 40-gallon breeder tank (36” L x 18” W x 16” H). With proper care, water snakes reach their adult size within two to four years.
Temperature and Lighting
Water snakes need a thermal gradient in their enclosure so they can warm up and cool down as needed. The recommended temperature for the warm end of a water snake’s habitat is 85 F, while the cooler end should be no lower than 70 F. Pet parents must check the temperatures of their snake’s habitat daily. Two thermometers-one in the warm area and one in the cool area-should be placed in the enclosure so that both zones can be checked at once.
Pet parents should install an under-tank heater and/or over-the-tank basking lamp with a heat bulb to supply radiant heat in their snake’s habitat. The wattage needed for the heat bulb will vary depending on the size of the enclosure, the distance of the bulb from the snake, and the ambient temperature of the room in which the enclosure is kept.
Lightbulbs should never be placed inside a snake’s habitat and should instead be suspended above the enclosure with a light fixture. White incandescent lights should not be left on continuously, as they will disrupt the snake’s natural sleep cycle and negatively affect their overall health. Studies show that daily exposure to UVA/UVB light can improve reptiles’ immune system function and promote normal behavior.
Humidity
Snakes need humidity in their environment to support their respiratory systems, encourage healthy shed cycles, and stay hydrated. The ideal humidity range for a water snake is 30-60%. A hygrometer (humidity gauge) should be used to measure the enclosure’s humidity.
To help maintain proper humidity levels, a snake’s habitat should include a water dish that’s large enough for the snake to soak in. While water snakes should always have access to water in their enclosure, their habitats should also include a waterless area that's lined with substrate so that the snake can dry out as needed.
Substrate and Furnishings
The substrate layer in a water snake’s habitat should be at least 1 to 2 inches deep to allow for burrowing. Wood shavings, reptile bark, mulch, and coconut husk bedding are all indigestible and can lead to life-threatening gastrointestinal obstruction if eaten.
Pet parents should provide their snake with at least two hideout boxes-one kept on the warmer side of the enclosure and one on the cooler side. Ensure any branches installed in the habitat are sturdy and strong enough to support the snake’s weight. Moist sphagnum moss can be added to the inside of a hideout box on the warm side of a snake’s enclosure to create a humid hide.
Cleaning
A water snake’s habitat needs to be cleaned and disinfected at least once a week with either a commercially available habitat cleaner or a 3% bleach solution. Move the snake to a secure environment. Scrub the empty tank and any furnishings with a reptile habitat cleaner or 3% bleach solution. The bleach solution should stay on the habitat for at least 10 minutes to ensure that the surfaces are properly disinfected.
Diet and Feeding
A nutritious and well-balanced diet for a water snake includes appropriately sized frozen rodents, thawed and warmed. Pet parents should begin juvenile snakes on a diet of “pinkies,” or young and nearly hairless mice. As the snake grows into adulthood, they can be transitioned to a diet of slightly larger immature mice (“fuzzies” and larger “hoppers”). Prey should be around the same size as the snake’s width at mid-body. Feeder fish should only be fed as an occasional treat. Many fish species contain an enzyme called thiaminase, which breaks down thiamine (vitamin B1) in snake’s bodies and can lead to a vitamin deficiency.
Fresh, clean water should always be available and replaced daily. Live rodents should not be given to water snakes. Ideally, feeding sessions should take place in a separate enclosure. That way, the snake will not learn to associate their pet parent’s hand or the opening of their usual habitat with feeding.
Put the frozen food in a sealed plastic bag and place it in a thawing container filled with cold water. Keep the food in the water until it thaws. Place the thawed prey, still in the sealed plastic bag, in the warm water. Remember: Pet parents should never use a microwave to thaw or warm frozen rodents, and never offer food that's still frozen to a pet. Frozen food that is not consumed should never be refrozen for future use, as this encourages bacteria to form in the food. Avoid preparing frozen rodents in the same area that you use to prepare food.
Shedding
Adult snakes shed their skin multiple times a year. Younger snakes that are actively growing tend to shed more frequently than adults. A snake’s eye caps, also called its spectacles, should come off with the rest of its shed skin. Snakes can soak themselves in shallow, open dishes of water to help shed their skin. Damp paper towels and moistened sphagnum moss can also be placed in the snake’s enclosure to encourage healthy shedding.
Veterinary Care
Due to their slow metabolisms, snakes can go weeks and even months without eating. However, they often become ill if they don’t eat for extended periods. Water snakes should be seen by a veterinarian once annually. They can be transported using a ventilated, latched, plastic-lidded bin, contained within a snake bag such as a pillowcase. Take photos of their enclosure, diet, heaters, and lights so your veterinarian can assess your snake’s husbandry as part of the exam.
Common Questions
Is a water snake venomous?
Water snakes are not venomous. They can look similar to other aquatic, venomous snake species such as cottonmouths and defend themselves more aggressively than most other non-venomous snakes.
What happens if a water snake bites you?
Water snakes are not venomous, but their bites can be painful. They have longer teeth and a stronger bite force than many other snake species, which can help them catch fish but can also cause a lot of damage when they bite a human. Despite their lack of venom, always seek medical assistance if you have been bit by a water snake.