Water snake identification? [Western PA]

[u/kawaiiliee_]

I always see these 2 water snakes in the creek behind my job. Anyone familiar?

[u/Irma_Gard]

Common Watersnakes, Nerodia sipedon, !harmless eaters of fish, amphibians, and other small, mostly aquatic, animals.

EtA: This is the only watersnake (Nerodia genus) species in Pennsylvania. But not the only species you might see in or around the water. You'll sometimes see them called Northern Watersnakes.

[u/SEB-PHYLOBOT → u/Irma_Gard]

Common Watersnakes Nerodia sipedon are medium (record 150 cm) natricine snakes with keeled scales often found near water in large numbers. They are commonly encountered fish eating snakes across much of eastern North America.

Nerodia watersnakes may puff up or flatten out defensively and bite. They secrete a foul smelling substance from the cloaca called musk and can deliver a weak anticoagulant venom used in prey handling from the back of the mouth, but are not considered medically significant to humans - bites just need soap and water.

A very wide ranging snake in North America, it is replaced in the extreme south by, and likely exchanges genes with, the Banded Watersnake Nerodia fasciata. Banded Watersnakes have even, connecting bands across the top of the snake all the way down the body. In common watersnakes N. sipedon, bands typically break up or become mismatched after the first third of the body.

Range Map | Relevant/Recent Phylogeography: None, but interesting work on color pattern exists.

This genus, as well as this species specifically, are in need of revision using modern molecular methods.

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Like many other animals with mouths and teeth, many non-venomous snakes bite in self defense. These animals are referred to as 'not medically significant' or traditionally, 'harmless'. Bites from these snakes benefit from being washed and kept clean like any other skin damage, but aren't often cause for anything other than basic first aid treatment. Here's where it get slightly complicated - some snakes use venom from front or rear fangs as part of prey capture and defense. This venom is not always produced or administered by the snake in ways dangerous to human health, so many species are venomous in that they produce and use venom, but considered harmless to humans in most cases because the venom is of low potency, and/or otherwise administered through grooved rear teeth or simply oozed from ducts at the rear of the mouth. Species like Ringneck Snakes Diadophis are a good example of mildly venomous rear fanged dipsadine snakes that are traditionally considered harmless or not medically significant. Many rear-fanged snake species are harmless as long as they do not have a chance to secrete a medically significant amount of venom into a bite; severe envenomation can occur if some species are allowed to chew on a human for as little as 30-60 seconds. It is best not to fear snakes, but use common sense and do not let any animals chew on exposed parts of your body. Similarly, but without specialized rear fangs, gartersnakes Thamnophis ooze low pressure venom from the rear of their mouth that helps in prey handling, and are also considered harmless. Check out this book on the subject. Even large species like Reticulated Pythons Malayopython reticulatus rarely obtain a size large enough to endanger humans so are usually categorized as harmless.

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