HOME : SPECIES ACCOUNTS : THE SNAKES OF INDIANA

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Snakes are an intriguing group of animals. Often misunderstood, they are an integral part of many natural habitats. Knowing more about them can help us enjoy the outdoors and appreciate the many different kinds of wildlife that surround us. This publication is intended to help people identify the snakes of Indiana, increase the awareness of snake conservation and biology, and correct many misconceptions about snakes.

TOPICS:

A List of Indiana’s Snakes

Snake Facts

Venomous vs. Nonvenomous Snakes in Indiana

Poisonous Snakes and Snake Bite

Snake Conservation

These web pages are based on the publication "Snakes of Indiana" authored by Brian MacGowan and Bruce Kingsbury, cooperatively produced by Purdue University, Indiana-Purdue University, Fort Wayne, and the Indiana Department of Natural Resources, Division of Fish and Wildlife. If you would like a copy of the booklet, you can obtain one for $7.50 (check, money order, or Visa/MasterCard- includes tax and shipping) from the DNR using the following contact information:

Snake Booklet

DNR Customer Service

402 W. Washington St. W160

Indianapolis, IN 46024

(317)232-4180

Snake Facts

Snakes are reptiles, a class of vertebrates that also includes lizards, turtles, crocodiles and the tuatara, a small group of lizard-like animals found in New Zealand. As a group, reptiles share many common characteristics. All reptiles have scales. They grow by literally “crawling out of their skin” two to four times annually- they must regularly shed the outside layer of their skin as they get bigger. Reptiles have a body temperature that is the same as their surroundings. They regulate their body temperature by basking in the sun when cold, or seeking shade and reducing activity when warm. Therefore, ambient temperature influences the daily activities of all snakes. For example, snakes tend to be more active during the middle of the day in the spring and fall when evenings are cool, and more active in the morning and evening during the hot summer months.

What makes a snake a snake? Snakes lack legs, unlike most other reptiles. However, boas have tiny spurs that are remnants of hind limbs, and a few other reptiles, such as worm and glass lizards, also lack limbs. Snakes move by pushing against objects with specialized scales on their bellies called scutes. The scutes act like tire treads, gripping the ground and giving the snake the traction necessary to push itself forward. Also, scutes are hard and protect the snake as it moves along rough surfaces. The scales covering the body prevent excessive dehydration by retaining body moisture and contain pigments that form the color patterns of snakes. Snakes have no moveable eyelids, and therefore can never blink or close their eyes. A single transparent scale covers the eye. They do not have external ears, but can hear by sensing vibrations through the bones in their head. In addition to being able to smell odors as we do, snakes can “taste” the air and ground using their forked tongue. Particles picked up by the tongue are processed by the Jacobson’s Organ in the roof of the mouth.

Most snakes mate in the spring after they emerge from hibernation. Depending upon the species, snakes can reproduce by either laying their eggs (oviparous) or by hatching the eggs internally and bearing live young (ovoviviparous). Some oviparous species in the state are kingsnakes, Black Rat Snakes, bullsnakes, racers, worm snakes, and green snakes. Snake eggs have a tough, leathery shell. Females lay their eggs in rotten logs or leaf litter. The eggs usually hatch in later summer to early fall. Water snakes, garter snakes, brown snakes, copperheads, cottonmouths and rattlesnakes all examples of ovoviviparous species in Indiana. The young of these snakes develop within the female in a sac-like membrane that contains yolk for nourishment. Some snakes break through this membrane before being born while others break through after their birth.

All snakes are carnivores, preying upon a variety of different animals including other snakes, fish, frogs, salamanders, rodents, insects, birds and slugs. Snakes have no claws or chewing teeth – they must eat their prey whole. They are able to eat prey larger than their head by allowing their jaws to disarticulate while swallowing and subsequently rearticulating the jaw when finished. Some snakes actively pursue their prey while others remain motionless and well camouflaged, waiting for unsuspecting prey to wander within striking distance. Snakes’ diets vary among species and depend upon their size and behavior. For example, small snakes typically prey upon small, slow-moving animals like slugs and earthworms. Larger snakes often prey upon larger, more active prey. Snakes lack chewing teeth, and therefore, must eat their prey whole. Also, snakes lack appendages to grip and hold prey. As a result, many species have developed intriguing methods for capturing, immobilizing and killing their prey. Some snakes are able to kill their prey by constriction, thereby suffocating their victim, while others make use of venom that immobilizes their prey.

Snakes have evolved a variety of defense strategies since they are preyed upon by mammals, birds, and even other snakes. Camouflage coloration may conceal a snake’s shape and confuse predators. When threatened, some snakes become immobile or “freeze” when they sense danger. Since many predators (hawks, owls, etc.) hunt by visual cues, they do not notice the motionless snake. Snakes also often employ a variety of bluffing behaviors. Several species vibrate their tail when threatened, making a rattling sound when it strikes dry leaves. Believing the snake to be a venomous rattlesnake, the predator may move on, unwilling to risk a potentially dangerous encounter. The eastern hog-nosed snake makes itself appear larger and more threatening by flattening its neck, and hissing loudly. If this does not work, these snakes will even play dead by lying on their backs and discharging a foul smell from specialized glands.

Venomous vs. Nonvenomous Snakes in Indiana

When someone encounters a snake, the first question that comes to mind for some is whether or not the snake is venomous. Most of Indiana’s snakes are not poisonous. In fact, there are only four venomous snakes in the state, and their distributions are limited (check the maps in the back of this booklet). All of the venomous snakes in Indiana belong to the pit viper family. Members of this family share common physical characteristics that separate them from nonvenomous species. Pit vipers have a sensory pit located between the eye and the nostril on each side of their head. These pits detect heat, thereby helping the snake locate warm-blooded prey, even in the dark. Other snakes lack these sensory pits. Thus, if it looks like your snake has four nostrils, it’s a pit viper. Of course, checking for pits requires getting a good look at the “business” end of the snake – to be safe, don’t get closer than the length of the snake. This brings up a general point: no one should ever attempt to handle a snake that is or may be venomous unless they have undergone extensive training by a professional. Even snake researchers avoid handling their venomous subjects whenever possible.

Because there are so few poisonous snakes in Indiana, we can impose some simple rules to help you to identify them. These rules will not work outside of this state or with exotic species. Indiana’s poisonous snakes are all very heavy-bodied – they look “fat.” They also have broad, spade-shaped heads that are distinctly wider than their narrow necks. The heads of nonvenomous snakes are typically about the same width as their bodies. Such distinctions are not completely reliable, as some species such as water snakes can be rather stout, and many species of snakes will flatten their heads when bluffing, giving the head a spade-like shape as well. Thus, having had a good meal should not be a death sentence for snake (but then, neither should being venomous!). The pupils of the venomous snakes of Indiana are vertical slits rather than round. This distinction may not hold elsewhere, but works in this state.

Do not attempt to handle or kill a snake that you believe may be venomous. Simply keep at a safe distance and move on your way. Snakes do not actively seek out people and bite them. Given the chance, snakes will almost always try to escape an encounter. If you leave them alone, they will make every effort to leave you alone as well. Be very careful to avoid the head when handling dead snakes. A snake’s reflexes can remain functional hours after death, and supposedly “dead” snakes have bitten people.

Perhaps the last point to emphasize regarding Indiana’s poisonous snakes is that most have limited distributions. This fact is discussed in detail in the species accounts later, but consider the following points. First, there is only one poisonous snake (the Eastern Massasauga Rattlesnake) in all of northern Indiana, and it is rare and lives in types of wetlands where people rarely go. Only a few are seen each year. The cottonmouth is restricted to a single small wetland in the southernmost part of the state. They are almost never seen in Indiana, even by specialists who know exactly where they should be. Thus, those water snakes people see while fishing around the state are simply common water snakes – they are not venomous. Timber Rattlesnakes are also rare, restricted to some of the forested hills in south-central Indiana. The most common venomous species is the Northern Copperhead, and even it has a restricted range in the hills of southern Indiana.

Venomous Snakes and Snake Bite

Although thousands of persons are bitten by venomous snakes every year throughout the United States, such bites in Indiana are very rare. Most bites occur when people are trying to kill or handle snakes. Snakes will always flee an area rather than strike, unless they are harassed or startled. While the bite of a poisonous snake is dangerous, it is rarely fatal - more people die from bee stings and lightening strikes annually. Nevertheless, immediate medical help should be sought in case a bite occurs.

Things you can do to prevent being bitten by a snake:

· If you know you will be in areas known to have venomous snakes, wear high-topped, leather hiking boots.

· Do not reach under rocks or logs, and do not step over logs. Step on them, then over.

· Be alert and search the area ahead of you. Do not merely look down at your feet. Be wary of areas containing logs or rocks. Remember that many venomous snakes blend in with their surroundings and may be difficult to see unless you are alert.

What if you are bitten?

In the event of a venomous snakebite, seek medical attention IMMEDIATELY. While it is helpful to identify the snake, do not waste time or risk being bitten again by capturing or killing the snake. The most important things to do if bitten are to stay calm and avoid excessive activity, and seek medical care as soon as possible. Do not make any incisions at the bite. Nonvenomous snakebites should be washed with soap and water to reduce the risk of infection. For the latest information on snakebite first aid, contact your nearest American Red Cross office or ask your physician.

Snake Conservation

Snakes have been declining in numbers throughout the state for many reasons. The primary reason for this is probably habitat loss. The development of wetlands and other critical habitats for human use has had a severe impact on the populations of snakes and other animals in the state. In addition, collection of snakes by hobbyists and reptile dealers has greatly contributed to their decline in the wild. Another contributing factor has been pesticide use. The overuse of pesticides has been detrimental to snakes that eat large quantities of insects and spiders. Finally, some snakes in Indiana were less common to begin with because Indiana represented the farthest extent of their range. Typically, species on the periphery of their range respond more strongly to fluctuations in numbers due to changes in environmental influences such as weather. However, these natural shifts in populations can be elevated by negative factors such as habitat loss and collection.

Like many other states, Indiana is making an effort to protect its reptiles and amphibians (herpetofauna). Thus the collection and possession of herpetofauna in the state requires a hunting or fishing license for all persons 17 years or older (unless you are collecting on your own farm). Bag limits and seasons are in place to regulate the number of reptiles and amphibians collected each year. Typically, in the case of animals such as snakes, the limit is four. These regulations were established due to the drastic declines in populations of snakes and other herpetofauna throughout the state. Without protection, these species would continue to decline. Endangered species may not be collected or possessed without special permits. There are additional requirements for dangerous species, or for having extra animals for breeding or conducting research. If you have any questions regarding the collection of snakes and other reptiles and amphibians, contact the Indiana Department of Natural Resources, Division of Fish and Wildlife at (317) 232-4080 or your local Conservation Officer.

There are many reasons for protecting snakes. They play an important role in controlling many yard and garden pests. Also, snake venom has been used in the development of many human medicines for blood and heart problems. Regardless of their direct benefits to us, all snakes have an important role in nature. They are a link in the chain of life and if one link is destroyed, the whole system may weaken and be jeopardized.

“The first rule of intelligent tinkering is to save all the parts.”

- Aldo Leopold

HOME : SPECIES ACCOUNTS : THE SNAKES OF INDIANA

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Bruce Kingsbury, Director

Center for Reptile and Amphibian Conservation and Management

Science Building

Indiana-Purdue University

2101 East Coliseum Blvd.

Fort Wayne, IN 46805-1499

herps@ipfw.edu