MSU Extension

Field guide to Michigan's 18 species of snakes, including the state's only venomous snake — Eastern Massasauga Rattlesnake. Large color photos and text with easy-to-follow symbols for habitat, temperament, reproduction and distribution make this book useful for all ages. Nontechnical, contains illustrations and key to identifying snakes, as well as sections on biology of snakes, snakes and people, controlling problems caused by snakes and treating snakebites. 

Introduction

Reptiles (an animal group that includes the turtles, crocodilians, lizards and snakes) are fascinating to many people , and snakes, along with the dinosaurs, are perhaps the most fascinating of reptiles. Unlike the dinosaurs, snakes are still living today, so they can be observed, studied and enjoyed. Michigan has 18 species of snakes, only one of which is venomous, and it occurs only in the Lower Peninsula.  

Like all living reptiles, snakes have backbones (an internal bony skeleton) and scaly skin. They breathe air, get their body warmth from their surroundings, and hibernate in winter if they live where the temperature goes below freezing for long periods. Snakes do not have legs, external ears or movable eyelids. They have a transparent, immovable eye covering; a dry, scaly outer skin that is shed in one piece; a single row of wide belly scales; and a skull with movable bones and loosely connected jaws that can spread widely so food can be swallowed whole.

This book is a reference for the identification of Michigan snakes, but other subjects-such as snake behavior, habitats, conservation and snakebite treatment-are included to help you better understand and appreciate snakes. This book is intended for the general public and is not a detailed work for the professional herpetologist. Consult the books on page 72 for additional information on snakes.

One easy way to identify a Michigan snake is to compare it with the pictures in this bulletin. If you find a picture that looks like the snake, then look at the range map to see if the species is known to occur in the area where you observed or caught it. If not, your identification may be incorrect. If the picture and range agree with what your snake looks like and where you found it, then carefully read the "identification" section to confirm your identification. Note that the size range given for each species is the total length for mature (adult) individuals.

The "habitat and habits" section is also useful in snake identification. A thick-bodied snake with an upturned nose ("identification" section) found in a sandy area eating a toad ("habitat and habits" section) can positively be identified as an Eastern Hog-nosed Snake in Michigan, even without the aid of a picture.

If you can look at a Michigan snake closely, another way to identify it is to use the Simplified Key to Michigan Snakes beginning on page 8. To use the key, start at the first set of paired descriptions and compare the two sets of characteristics given. Choose the one ("a" or "b") that better fits the snake and proceed to the next number indicated and compare those two. By this process of elimination, you will eventually arrive at the name of the snake and the page number of its picture, range map and description. Then read the species account and examine the map and picture to verify your identification. The illustrations on page 6 show the identifying characteristics used in the key.

This book will enable you to distinguish Michigan's 17 non-venomous snake species from one another and from the one venomous species. Equally important, this booklet introduces you to an often poorly understood but important, interesting and enjoyable part of our wildlife heritage.

Family Colubridae

Subfamily Natricinae

Kirtland's Snake - Clonophis kirtlandii

Copper-bellied Water Snake - Nerodia erythrogaster neglecta

Northern Water Snake - Nerodia sipedon sipedon

Queen Snake - Regina septemvittata

Brown Snake - Storeria dekayi

Northern Red-bellied Snake - Storeria occipitomaculata occipitomaculata

Eastern Garter Snake - Thamnophis sirtalis sirtalis

Butler's Garter Snake - Thamnophis butleri

Northern Ribbon Snake - Thamnophis sauritus septentrionalis Page 33 4

Subfamily Xenodontinae

Northern Ring-necked Snake - Diadophis punctatus edwardsi

Eastern Hog-nosed Snake - Heterodon platirhinos

Subfamily Colubrinae

 Blue Racer - Coluber constrictor joxii

Black Rat Snake - Elaphe obsoleta obsoleta

Eastern Fox Snake - Elaphe gloydi

Western Fox Snake - Elaphe vulpina

Eastern Milk Snake - Lampropeltis triangulum triangulum

Smooth Green Snake - Liochlorophis vernalis

Family Viperidae

Subfamily Crotalinae

 Eastern Massasauga Rattlesnake - Sistrurus catenatus catenatus