Copperhead Snakes and Water Snakes

Copper Head Snakes and Water Snakes

Michael McCarthy flicker sharing 3 copperhead

Copperhead snake (Photo: Michale McCarthy, Flicker sharing)

Identification of the venomous copperhead snake and the harmless northern banded water snake

In the Eastern US one of the biggest fear of homeowners and people who work or play outside, is of venomous spiders and snakes. However, in fear of these creatures, other non-venomous and beneficial species are often misidentified and killed. Today's post is how to tell if a snake is a copperhead snake (Agkistrodon contortorix) or the harmless northern banded water snake (Nerodia sipedon). Both look similar, but they have some key differences.

Let's Begin with Copperheads....

Copperhead snakes are the most common venomous snake in the Eastern US. They are in the pit viper family (Crotalidae). They are also in the genus Agkistrodone, which includes the cottonmouth or water moccasin. It is a shy snake that is usually not aggressive, and its bites are rarely fatal, though they can be painful.

POISONOUS VERSUS VENOMOUS

Animals that inject venom are called venomous, and not poisonous. You might have heard these terms used synonymously. There are no true poisonous snakes, only venomous snakes. Things that are poisonous can make you sick if you eat them. Animals that are venomous inject venom, usually through fangs, stingers, or spines (like lionfish, sea urchins, spiders, and snakes). Venom serves as a way to help animals eat, subdue prey, and sometimes as a means of defense.

Poison, however,  is usually a defensive mechanism that prevents organisms from being eaten. Frogs, toads, salamanders, plants, mushrooms, and poison ivy are all poisonous.  As usual, in nature, there is one exception which is an Asian snake, Rhabdophis tigrinus which eats poisonous toads. By ingesting the toads the snake becomes poisonous to eat. You can read the abstract in the US National LIbrary of Medicine, NIH paper if you'd like to know more.

Copperhead venom is hemolytic, which means that it functions by destroying red blood cells, causing hemorrhaging in animals. However, this same venom is being studied by researchers because it has properties that may be used to "paralyze" cancer cells to stop them from spreading. You can read more from from the Journal of the National Cancer Institute.

Here's a primer on how to tell venomous snakes from nonvenomous snakes.

1. Look at the head shape. Non-venomous snakes, with the exception of brown water snakes, have rounded heads, while venomous snakes have triangular heads.

Tom spinker timber rattler head flicker

Notice the arrow shaped head of this venomous garter snake (Photo: Tom Spinker flicker sharing).

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This nonvenomous garter snake has a rounded head. (Photo: Wiki commons)

2. There is a small and shiny cap of scales between the eyes, and over the nose of venomous snakes. Nonvenomous snakes have a smooth shiny cap that covers most of their head.

David flicker, black rat snake head scales

Nonvenomous snakes like the black rat snake, have caps of large scales on their heads. Look at the image of the rattle snake above, and you will see only a small cap near the nose. (Photo: David Flicker sharing)

3. Venomous snakes have slit-eye pupils, like a cat, while nonvenomous snakes have round eyes. If you don't want to get close enough to the snake to see this, then take a photo with a long lens, and then look at it on your camera. Remember: "Round, safety is found," or "Eyeball is slit, you're gonna get bit (by the venomous snake)."

non venomous snake with head and eye

This is a nonvenomous snake, notice the round head and round pupil. (Photo: Wiki commons).

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Check out the slit pupil and heat sensing pit on this venomous rattle snake. (Photo: Wiki commons).

4.Venomous snakes also have a heat sensing pit between their nostril and eye. Nonvenomous snakes do not.

5. Venomous snakes have undivided scales from their vent (poop chute), down to the tip of their tail. Nonvenomous snakes have divided scales from the vent down. I know you're saying, hey, wait, I'm not getting that close! You don't have to. If you find a shed snake skin you can use it for identification.

Ventral_scales_of_Naja_nivea_around_anal_region_IMG_0886s

In the US (not true in all countries) our venomous snakes one single row of scales just below the vent (poop shoot) on the underside of the snake's tail. Nonvenomous snakes have a split row of scales, like in the picture above (Photo: Wikicommons).

6. Venomous snakes have movable fangs that can retract into their head. Nonvenomous snakes have fixed teeth.

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This is the skull of a constricting snake, that does not use venom. Notice the fixed teeth, and no long central fang (Photo: Wiki commons).

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This venomous snake has retractable fangs (Photo: Wiki commons).

WHERE TO FIND COPPERHEADS

They prefer woodland areas, round rocks or near streams and ponds, because there is plenty of prey and food in these locations. They mainly eat rodents and mice, though they will also eat voles, frogs, lizards, cicadas, birds and other insects if available.

They also tend to favor stones, garden walls, stone fences, compost piles, wood piles, and under building debris. They also like stone ledges and swampy low-lying areas. They may also den in large groups or hibernaculums starting in the fall, and continuing until February or March.

PICTURES OF COPPERHEAD SNAKES AND WHAT TO LOOK FOR

Michael McCarthy flicker sharing 2

This is a good example of a common copperhead coloration. Notice that the "hour glass" pattern does not necessarily meet in the middle of the snake's back (Photo: Michael McCarthy Flicker sharing).

General Characteristics: 

  • See notes above about features of venomous snakes.
  • Different color variations: from blackish to pink.
  • Color varieties all have the characteristic copper head.
  • All of them have bands that go across their bodies that usually look like hour glasses (10-18 bands usually).
  • Cross-bands can look like hour glasses or Hershey kisses. In many cases the hour glass or "kiss" don't meet in the middle.
  • Often the outer edges of the "kiss" are also darker.
  • Adults can be 2-4 ft. long.
  • Thickish stout snakes.
  • Belly is the same color as the ground usually.

TYPES OF COPPERHEADS IN THE EASTERN US

There are two subspecies of copperhead in the Eastern US, the Southern copperhead (Agkistrodon contortrix contortrix) and the Northern copperhead (Agkistrodon contortrix mokasen). The main difference is in their range, from the Northern to Southern US, though there is some overlapping around the Appalachian mountain region.

It's difficult to make any generalizations about color patterns between Northern and Southern, since they are very close.

Agkistrodon_contortrix_mokasen_CDC Northern copper

Northern copperhead snake, A.C. mokasen (Photo: Wiki commons).

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Southern copperhead snake, A.c. contortrix (Photo: Wiki commons).

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Northern copperhead (Photo: Wiki commons).

N. copperhead flicker West Virginia Blue Flicker

Northern copperhead (Photo: West Virginia Blue, Flicker sharing).

Northern copperhead Zack flicker

Northern copperhead (Phoot: Zack, Flicker sharing).

Southern copperhead Patrick Feller

Southern copperhead (Photo: Patrick Feller, Flicker sharing).

PICCTURES OF BABY COPPERHEAD SNAKES

Female copperhead snakes are ovoviviparous, meaning that they carry their eggs in their bodies, until the eggs are ready to hatch, and then they release the eggs and the young hatch out immediately. The young copperheads are easy to tell apart from nonvenomous species because they have a very lemony yellow tail, which they keep until they're over about a year old.

Juvenile copperhead snake cliffanddally flicker 3

This juvenile copperhead has the characteristic lemony yellow tail tip for caudal luring (Photo: Cliffanddally Flicer sharing).

Juvenile copperhead snake cliffanddally flicker 2

This juvenile copperhead has the characteristic lemony yellow tail tip for caudal luring (Photo: Cliffanddally Flicer sharing).

Juvenile_copperhead_snake Wiki

Note the lemony coloring of the tail tip of this juvenile copperhead (Photo: Wiki commons).

Tail coloring, or caudal coloring as it's known to scientists, is thought to be for caudal luring. This means that the juvenile snakes wriggle the little yellow tip in the leaves, making it look like food for insects, birds, mice, or other creatures, that then become food for the snake when they approach. This is not uncommon in pit vipers.

copperhead tongue

Note the long tines of this copperhead's tongue. This is another form of scenting or smelling, using the tongue (Photo: Willik commons).

Not that you ever want to get close enough to tell, but the males have been proven to have slightly longer tongue tines than females during the breeding season. This is because the males have to use their tongues to "scent" where the female is. They literally smell her out. Having a long tongue is helpful for this. Check out the paper in the Journal of Zoology to learn more.

COMPARING WATER SNAKES TO COPPERHEADS

Now that you have a working idea of what a copperhead looks like, I want to defend my friend the common water snake, sometimes called the banded water snake.

Banded water snakes are harmless, nonvenomous fish eaters. Like the copperhead, they hunt along water edges, rocks, under logs, etc. They also have a similar diet, though the water snakes tend to eat more minnows, crayfish, salamanders, etc.  In our region they swim both in fresh and brackish water. Both copperheads and water snakes can swim well.

It's easy to get the two confused, and many, many water snakes have been killed by mistake. Take a look at the pictures below. You can see that the water snake has a wide variation of color patterns, just like the copperhead; however, they do not have hour glass shaped bands, and they have the physical characteristics of nonvenomous snakes (eyes, head scale pattern, vent scales, eye etc.). Their bands go all the way across and are usually much thicker than the hourglass or Hershey kiss of copperheads.

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Banded water snake (Photo: Karen McDonald)

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Banded water snake (Photo: Karen McDonald)

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Banded water snake (Photo: Karen McDonald)

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This is a banded water snake fresh from hibernation. He's been covered in mud, and lost his coloration. As he dries out and get some sun he'll change color (Photo: Karen McDonald)

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This is a juvenile banded water snake, it has smaller stripe patterns (Photo: Karen McDonald)

The main confusion between water snakes and copperheads comes from their head shape and coloration. Unfortunately, they are very close to each other, and there is a great deal of variety. Unlike most nonvenomous snakes the water snake also has a triangular head.

If you're not sure which snake is which, then leave them both alone. If they are not an immediate threat to people or pets, just leave the area, and try to avoid them. These snakes are an important part of the food web, helping to control pest populations and keep the balance of other organisms. They are shy, and really want to avoid you too!

FOR THE CURIOUS: COPPERHEAD BITES

Copperheads are solenoglyphous, meaning that the fang size is directly proportional to the snake's size. The bigger the snake, the bigger the fangs! However, hatchling copperheads do have functioning fangs that can release venom that is just as toxic as the adults.

I'm not going to go into the details of copperhead bites and how to treat them here. If you want to know more, there's plenty of information available through the Center for Disease Control (CDC) and other. Here are a few websites:

  • http://www.cdc.gov/niosh/topics/snakes/
  • http://www.bt.cdc.gov/disasters/snakebite.asp
  • http://www.nlm.nih.gov/medlineplus/ency/article/000031.htm

WATER SNAKE V. COPPERHEAD SNAKE QUIZ

Are you ready to see if you could pass the watersnake v. copperhead quiz? I'll show you pictures below, see if you can guess correctly. Answers are at the bottom of the page.

1024px-NorthernWaterSnake23

A. (Photo: Wiki commons)

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B. (Photo: K. McDonald)

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C. (Photo Wiki Commons)

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D. (Photo: K. McDonald)

Michael McCarthy flicker sharing

E. (Photo: Michale McCarthy, Flicker sharing)

1024px-Northern_watersnake_j

F. (Photo: Wiki commons).

juvenile copperhead snake cliffanddally flicker

G. (Photo: Cliffanddally Flicker sharing).

Answers:

  • A: water snake
  • B: water snake
  • C: copperhead
  • D: water snake
  • E: copperhead
  • F: water snake
  • G: copperhead