Thank you for your question. The snake in your photo is the northern watersnake, scientific name Nerodia sipedon. They are non-venomous.
This species is found in all the eastern states and portions of North and South Carolina and Georgia, Alabama, Mississippi, Louisiana, the panhandle of Florida and from Michigan and Wisconsin south.
Typical length is a little less than 3 feet, and maximum lengths of approximately 5 feet have been recorded. This species has one of the most varied diet of any of our watersnakes. Research studies have documented this snake preying on over 80 fish species and 30 amphibian species. In addition, invertebrates such as insects, earthworms and leeches have also been captured as prey.
They can be found in just about any water body in their range, including rivers, swamps, marshes, lakes, ponds and wetlands. They are often observed basking on rocks and logs near the water or in low hanging branches that extend over the water. If threatened, they immediately dive into the water and disappear below the surface.
If cornered this species will inflate its body and flatten its head to appear bigger. They will also strike repeatedly and bite if you get too close. If you pick them up they will expel a strong-smelling musk from their anal glands and bite repeatedly in an effort to get away.
This northern watersnake and other species of common watersnakes are often mistakenly identified as the venomous cottonmouth (Agkistrodon piscivorus), which does not occur in New York, and needlessly killed.
For more information on these and other snakes of New York, check out the State University of New York College of Environmental Science and Forestry at:
An excellent field guide for snakes in your area is:
Gibbons, Whit. (2017). Snakes Of The Eastern United States. Athens: The University of Georgia Press.
Hope this answers your question, and thank you for contacting Ask an Expert.
Thank you so much Jim for your fast reply. Glad to know this info as I have a dog that chases anything in the yard. Will sure be a little more watchful now
You're welcome. Contact us any time.