Nerodia fasciata - Southern Watersnake

Nonvenomous

Considered harmless to humans, but the snake's saliva may produce inflammatory reactions around the site of a bite.

Size

Adults are generally 22 - 40 inches long (56 - 101 cm) and up to 60 inches (152 cm.)

Appearance

A dark, heavy-bodied snake with heavily-keeled scales. Color is yellowish to reddish-gray with 40 or more dark crossbands on the entire length of the body. Old snakes may be almost entirely solid dark brown. There is a dark stripe extending from the eye to the corner of the mouth. The head has a more acute downward angle than Nerodia sipedon.

Dark spots mark the venter, typically dark square or triangular spots sometimes with wavy cross lines.

Juveniles are paler with a stronger pattern than adults.

Behavior

Active during the day, and also at night. If threatened, may emit a strong-smelling musk and feces from its cloaca, flatten its body and strike repeatedly. Basks in the sun at water's edge on logs or overhanging limbs, moving into dens along banks in cold weather. Will leave the water and travel overland a mile or more in search of food.

Diet

Eats fish, frogs, salamanders, crayfish.

Reproduction

Live-bearing.

Range

Introduced in and around Lake Natoma in the city of Folsom, Sacramento County, and in Harbor City.

According to Michael Fuller of the Nerodia Working Group, a reproducing population of N. fasciata has existed in Harbor City for several years. While the snakes key out to N. f. pictiventris morphologially, preliminary mDNA results (as of 9/08) suggest that they are Nerodia clarkii, or possibly hybrids of N. clarkii and N. f. pictiventris. The habitat is a freshwater lake, typical of that used by N. fasciata, while N. clarkii typically inhabit brackish waters.

Habitat

Occurs in and around permanent bodies of water, especially those bordered by woods.

Conservation Issues

(Conservation Status) Spread of this snake downstream into the Sacramento Valley could possibly threaten populations of the already endangered Giant Gartersnake, Thamnophis gigas. It could also pose a threat to other native fish and wildlife.

It is against the law to capture, move, possess, collect, or distribute this invasive species in California. See: California Department of Fish and Game Restricted Species Regulations