Herpetofauna: One Life's List

Nerodia sipedon pleuralis
Midland Water Snake

Mingo Swamp, Missouri. May 1984

Other than pattern and color, these are essentially Northern Water Snakes, which they intergrade with on a wide band across the Midwest.  The one in the top right picture is a Northern-Midland intergrade from central Indiana, in what is any sipedon's favorite hangout, a big brushy logjam on the creekbank.  It can be very difficult to spot them in these brush piles, and oftentimes there are more snakes there than the eye can see! 

The bottom right picture is a pleuralis from Pike Co., Illinois, near the Mississippi River.  The picture below is a specimen from the Cache River in southern Illinois.