Northern Watersnake

Scientific Name: Nerodia sipedon sipedon
Size: 24-55 in. (61-140 cm) in length
Status: Abundant

Habitat:
Wide variety of aquatic and semi-aquatic habitats. Lakes, ponds, rivers, streams, creeks, canals, swamps, marshes, and wet meadows. May be found under rocks, logs or boards, but are mainly seen in the open basking or swimming.

Description:
Medium-sized, heavy-bodied species with strongly keeled scales. The head is distinct from the body. The background of the upper body is greyish brown, light brown, tan or grey with a series of brown to reddish brown wide saddles on the front third of the body that are wider at the vertebral area and become narrow towards the ventral (belly) margin, and a series of dark brown or gray or orange alternating rectangular blotches along the back and sides. Saddles and blotches number from 25-36. The background of the belly is cream to yellow-brown or red with a bold pattern of many reddish brown to brown crescent blotches bordered with black. The head is greyish brown to brown with variable dark markings. The scales that border the mouth opening along the upper jaw are cream to beige with dark vertebral bars along the sutures. The chin and throat are cream to yellow. Adults and shedding individuals may appear to have a uniform brown to dark grey dorsal. Young are brighter and have a higher contrasting pattern that darkens with age.

Adult Coloration:
  • The dorsal background is greyish brown, light brown, tan to grey.
  • The dorsal pattern has a series of brown to reddish brown wide saddles on the anterior third of the body that are wider at the vertebral area and become narrow towards the ventral margin, and a series of dark brown alternating rectangular blotches along the back and sides.
  • Saddles and blotches number from 25-36.
  • The dorsal background of the head is greyish brown to brown with variable dark markings.
  • The ventral background is cream to yellow-brown or red with a bold pattern of many reddish brown to brown crescent blotches bordered with black.
  • The chin, throat cream to yellow.
  • The supralabials are cream to beige with dark vertebral bars along the sutures.
  • Adults and shedding individuals may appear to have a uniform brown to dark grey dorsal.
Adult Characteristics:
  • Medium-sized, heavy-bodies species.
  • Scales are keeled.
  • The head is distinct from the body.
Juvenile Characteristics:
  • Higher contrasting pattern that darkens with age.
Scale Count:
  • 23 scale rows at midbody
  • 21 scale rows at anterior
  • 17-19 scale rows at posterior
  • 123-155 ventral scales
  • 42-84 subcaudals | 2 rows of subcaudals
  • 1 loreal scale
  • 1 preocular scale
  • 3 postocular scales
  • 1+2-3 temporal scales
  • 6-9 supralabials
  • 10 infralabial
  • Anal plate is divided
Range:

May be Confused With:
References:
  • Hulse, C. and McCoy C. J. and Ellen Censky ,1998. Amphibians and Reptiles of Pennsylvania and the Northeast. 302-305pp.
  • Ernst, Carl H. and Ernst, Evelyn M. ,2003. Snakes of the United States and Canada. 246-254pp.
Credits:
  • Jason Poston
  • Wayne Fidler
  • Bob Ferguson
  • Sebastian Harris
  • Don Becker(psychoticnature.com)
  • Stephen Staedtler

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