Northern Water Snake

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

Habitat Type:
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.

Colorations:
Adults:

  • 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.

Juveniles:

  • Higher contrasting pattern that darkens with age.

Characteristics:

  • Medium-sized, heavy-bodies species.
  • Scales are keeled.
  • The head is distinct from the body.

Scale Counts:

  • 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

Confused with:

  • Milksnake
  • Hognose
  • Copperhead

Coloration/Pattern Photos:
Adults:
Northern Water Snake - By: Wayne Fidler Northern Water Snake - By: Wayne Fidler Northern Water Snake - By: Wayne Fidler
Northern Water Snake - By: Wayne Fidler Northern Water Snake - By: Jason Poston Northern Water Snake - By: Jason Poston
Northern Ringneck Snake - By: Wayne Northern Water Snake - By: Wayne Fidler Northern Water Snake - By: Wayne Fidler Northern Water Snake - By: Wayne Fidler

Juveniles:
Northern Water Snake - By: Jason Poston Northern Water Snake - By: Jason Poston Northern Water Snake - By: Jason Poston

Range Map:
Northern Water Snake Range Map

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.

Photo Credits:

  • Jason Poston
  • Wayne Fidler