Brown water snakes are found in southeastern North America, along the Coastal Plain from Virginia south through the lowlands of the Carolinas, most of Georgia, all of Florida and southern Alabama.

Biogeographic Regions: nearctic (Native )

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) The range encompasses the Coastal Plain from Virginia to southern Florida, and west to Alabama, and also the piedmont of the Carolinas and Georgia (Mount 1975, Tennant 1984, Mitchell 1994, Palmer and Braswell 1995, Ernst and Ernst 2003).

Nerodia taxispilota ranges in length from 28 to 69 inches (71.1cm-175.3 cm). The record length is 69.5" (176.6 cm). Females are larger; males do not reach the size of the largest females. Brown Water Snakes are relatively heavy-bodied, and have a large head distinctly wider than the neck. This produces a heart- or diamond-headed appearance (if viewed from above) that makes this species easy to confuse with venomous snakes in the Viperidae family (such as cottonmouths (Agkistrodon piscivorous) and rattlesnakes. Nerodia taxispilota is brown to dark brown in color (indicated by its common name). The most distinctive mark is the separation between its large brown (usually light-edged), squarish vertebral blotches that occur along the lengths of its body. These blotches alternate with a row of similar blotches on each side of the body. Many specimens are exceptionally dark, being a deep chocolate brown in gross appearance and with blotches only a little darker than ground color. The belly of -N. taxispilota- is yellow to brown and boldly marked with brown splotches and black crescents. These markings are often arranged in broken rows along its sides. The dorsal scales of Nerodia taxispilota are strongly keeled in 25-33 midbody rows, and its anal plate is divided. The tail tapers abruptly, and its eyes are high and set forward towards the nose.

Length: 175 cm

• Freshwater

Nerodia taxispilota is most common in and around clear, quiet waters, on fallen trees, or even bushes suitable for basking. The species has been collected in lakes, rivers, streams, cypress swamps and waterways, canals, drainage ditches, and ponds, especially where overhanging vegetation is present. It is also common around hardwood hammocks of wet materials, sawgrass prairies, bottomland forests, and near tree-bordered margins of brackish tidal marshes.

Terrestrial Biomes: forest

Aquatic Biomes: lakes and ponds; rivers and streams

Comments: This snake inhabits rivers, large creeks, lakes, ponds, reservoirs, swamps, and marshes, including brackish tidal waters in some areas; it often climbs into woody vegetation overhanging the water, and it also perches on fallen trees, jetties, duck blinds, debris or other object along shorelines (Ernst and Ernst 2003, Gibbons and Dorcas 2004). In South Carolina, is was significantly associated with the steep-banked outer bends of the river and with areas having good perch-site availability; only large individuals crossed a 100-meter-wide river (Mills et al. 1995).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

In South Carolina, seasonal movements may have occurred; relatively large movements were recorded in late summer-early fall (Mills et al. 1995).

Nerodia taxispilota is piscivorous, preying primarily benthic-feeding fish (mostly minnows, some juvenile catfish), and on frogs. Fetal brown water snakes are nourished by fat yolks deposited within their membranous egg shrouds. Thus female Nerodia taxispilota must acquire lipid reserves well in advance of pregnancies. Gravid females are limited in their hunting strategies (because of their weight) and may rely on scavenging.

Comments: Eats mainly fishes, sometimes frogs (Mount 1975; Mills and Hudson 1995, Herpetol. Rev. 26:149).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: This species is represented by a large number of occurrences (subpopulations). Palmer and Braswell (1995) maped well over 100 collection sites in North Carolina alone.

100,000 - 1,000,000 individuals

Comments: Adult population size is unknown but presumably exceeds 100,000. This snake is often locally common to abundant in suitable habitat (Gibbons and Dorcas 2004).

In South Carolina, density was estimated at 43 individuals per km of river habitat; most individuals were found within 250 m of their previous capture location, but a few moved more than 1 km (Mills et al. 1995).

Comments: Mostly diurnal though sometimes active at night.

Average lifespan

Status: captivity: 6.1 years.

This species breeds between late February and early May, with neonates appearing between June and October. Snakes don't have set gestation periods because pregnancy is initiated by the females' ovulation, not by deposition of semen. Viable sperm may be stored for months or even years within the cloaca of inseminated but not-yet-fertilized females. Female Nerodia taxispilota must increase their body's store of lipids by some 50% in order to become pregnant. They give live birth to as many as 60 offspring at once. These offspring range from 7 to 11 inches in length, and their coloring is much brighter than that of their parents.

Gives birth to about 14-45 young in summer and early fall. Larger females have larger litters. In central Georgia, courtship occurred in late April-early May; young were born in late August-early September; males were sexually mature in 2.5 years, females in 3.5 years (Herrington 1989).

Nerodia taxispilota is fairly abundant (so much so that in favorable habitats, 12 or more can be seen in the same area in a small amount of time).

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Global Short Term Trend: Relatively stable (=10% change)

Comments: Currently, extent of occurrence, area of occupancy, number of subpopulations, and population size probably are relatively stable.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: No major declines have been recorded, aside from local reductions in limited portions of the range.

Comments: No major threats are known. Declines may have occurred at the periphery of the range and in areas subject to intense urbanization or pollution (Gibbons and Dorcas 2004). Many watersnakes are killed by people who fear that the snakes are venomous (Mitchell 1994). However, in most areas, this species apparently faces no significant threats.

Global Protection: Very many (>40) occurrences appropriately protected and managed

Comments: Many occurrrences are in protected areas.

Nerodia taxispilota has no economic importance (positive or negative) for humans.

Nerodia taxispilota has no economic importance (positive or negative) for humans.

Comments: Formerly included in genus Natrix.