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This site was created by students in the herpetology class at Towson University.  Site last updated: 05/21/07.

Acknowledgements: Herb Harris - Range Maps;  Mark Tegges - Photography; Dan Lapascha & Gigi Forester - TU Herpetology Logo

Northern water snake

Description

The northern water snake is a thick-bodied snake, with an adult length of 24 to 55 inches.  Coloration and patterning of the northern water snake is quite variable.  The dorsal color ranges from gray to brown with reddish-brown to black blotches.  Blotches tend to fade out as adults age, resulting in adults that are often a uniform dark brown or black.  The ventral surface is usually light colored patterned with reddish-brown half moon shapes.  Scales are strongly keeled, the anal plate is divided, and there are 21 to 25 mid-dorsal scales.

Habitat

Northern water snakes occupy most aquatic habitats, such as lakes, rivers, streams, sloughs, ponds, and marshes.  They can often be found basking on rocks, beaver dams, or overhanging logs.  They are skilled swimmers but occasionally venture onto land at the water’s edge.  The diet of northern water snakes includes amphibians, fish, large invertebrates, snakes, small mammals, and turtles. 

Breeding

Courtship and mating typically occur in May or June.  The male will come alongside the female and rub his chin along her back.  He then wraps his tail around hers until there is cloacal contact. Northern water snakes are ovoviviparous, with the female giving live birth to between 20 and 50 young in August or September.  No parental care is provided after birth, and newborns range between 6 and 10 inches long.  Males will be sexually mature after about 21 months, and females will be able to breed at 3 years of age.

Distribution in Maryland

Range map adapted from Harris, 1975. 

Links

http://animaldiversity.ummz.umich.edu/site/accounts/information/Nerodia_sipedon.html

http://www.umass.edu/nrec/snake_pit/pages/nwater.html

http://www.inhs.uiuc.edu/cbd/herpdist/species/ne_sipedon.html