Discover Maryland's Herps

Field Guide to Maryland's Snakes (Order Squamata)

Sub-order Serpentes

Snakes
27 species and sub-species in Maryland

Snakes are limbless reptiles with elongate bodies that are covered with scales. All snakes lack external ear openings and eyelids and have long, forked tongues.

There are twenty-seven different varieties (species and sub-species) in two families of snakes that can be found in Maryland.

Two Maryland species, the copperhead (Agkistrodon contortrix) and timber rattlesnake (Crotalus horridus) are in the viper family (Viperidae). The remaining species are in the family Colubridae, which is the largest snake family in the world.

Click here for a Table that shows whether the scales of each snake species are keeled, weakly-keeled, or smooth and whether the anal plate is single or divided. These characteristics along with the number of dorsal scale rows at the mid-body and the overall coloration and patterning are important characteristics used to differentiate species of snakes (White and White 2002). With a few exceptions, most young snakes resemble adults (Mitchell 1994). Eggs of snakes can be differentiated by species. However, characteristics used to identify species of snakes based on examination of eggs are not discussed in this document.

Snake Anatomy

Snake Family

Number of Species & Subspecies in Maryland

Viper (Viperidae)

2

Colubridae

25

Pit Vipers (Subfamily Crotalinae)

There are two species of pit vipers found in Maryland, the timber rattlesnake (Crotalus horridus) and the copperhead, which includes the subspecies northern copperhead (Agkistrodon contortrix mokasen) and intergrade (Agkistrodon c. contortrix X mokasen). Both of these species are dangerously venomous and should be treated with caution. Do not approach or handle these snakes as a bite could be fatal. As the name implies the pit vipers have a heat seeking pit between each eye and nostril. The pit vipers also differ noticeably from the colubrids by having vertical pupils, and undivided subcaudal scales (Conant and Collins 1998).

Click on a picture or species name for profiles
of each of the 2 species and subspecies of Maryland’s pit vipers.

  Common Name Scientific Name State Status

Northern Copperhead, photo courtesy of Linh Phu

Northern Copperhead

and

Intergrade
Agkistrodon contortrix mokasen

and

Agkistrodon c. contortrix X mokasen

 

Timber Rattlesnake, photo courtesy of Scott A. Smith

Timber Rattlesnake Crotalus horridus Watchlist

Colubrids (Family Colubridae)

Maryland colubrids differ from vipers by having round pupils in the eyes, no heat seeking pit between each eye and nostril, a complete set of divided sub-caudal scales, and a series of large plates (scales) on the dorsum of the head.

There are 26 different types of snakes (including sub-species) from the family colubridae that can be found in Maryland. Due to the large number of genera (16) and the relatively few species within each genus (no more than two), identification of Maryland colubrids to genus is not discussed here. Species and sub-species descriptions follow.

Click on a picture or species name for profiles
of each of the 25 species and subspecies of Maryland’s colubrids.

  Common Name Scientific Name State Status

Northern Watersnake, photo courtesy of Scott A. Smith

Northern Water Snake Nerodia sipedon sipedon  

Red-bellied Watersnake, photo courtesy of Dave Wilson

Red-bellied Watersnake Nerodia erythrogaster erythrogaster Watchlist

Queen Snake, photo courtesy of John White

Queen Snake Regina septemvittata  

Eastern Smooth Earthsnake, photo courtesy of John White

Eastern Smooth Earthsnake Virginia valeriae valeriae  

Mountain Earthsnake, photo courtesy of Don Forester

Mountain Earthsnake Virginia valeriae pulchra Endangered
Northern Brownsnake, photo courtesy of Scott A. Smith Northern Brownsnake Storeria dekayi dekayi  
Northern Red-bellied Snake, photo courtesy of Mark Tegges Northern red-bellied Snake Storeria occipitomaculata occipitomaculata  
Eastern Gartersnake, photo courtesy of Corey Wickliffe Eastern Gartersnake Thamnophis sirtalis sirtalis  
Common Ribbonsnake, photo courtesy of Corey Wickliffe Common Ribbon Snake Thamnophis sauritus sauritus  
Southern Ring-Necked Snake, photo courtesy of MattClose Northern Ring-Necked Snake and

Southern Ring-Necked Snake and

Intergrade

Diadophis punctatus edwardsii

Diadophis punctatus punctatus


Diadophis p. punctatus X edwardsi

 
Eastern Wormsnake, photo courtesy of Linh Phu Eastern Wormsnake Carphophis amoenus amoenus  
Smooth Greensnake, photo courtesy of Matt Sell Smooth Greensnake Opheodrys vernalis  
Northern Rough Greensnake, photo courtesy of Tony Prochaska Northern Rough Greensnake Opheodrys aestivus aestivus  
Eastern Hog-nosed Snake, photo courtesy of John White Eastern Hog-nosed Snake Heterodon platirhinos  
Common Rainbowsnake, photo courtesy of John White Rainbow Snake Farancia erytrogramma erytrogramma Endangered
Northern Black Racer, photo courtesy of John White Northern Black Racer Coluber constrictor constrictor  
Northern Pinesnake, photo courtesy of John White Northern Pinesnake Pituophis melanoleucus melanoleucus Historical
Red Cornsnake, photo courtesy of Linh Phu Red Cornsnake Pantherophis guttatus  

Eastern Ratsnake, photo courtesy of Linh Phu

Eastern Ratsnake Pantherophis alleghaniensis   

Mole Kingsnake, photo courtesy of Mark Tegges

Mole Kingsnake Lampropeltis calligaster rhombomaculata  

Eastern Kingsnake, photo courtesy of Corey Wickliffe

Eastern Kingsnake Lampropeltis getula getula  

Eastern Milksnake, photo courtesy of Matt Close

Eastern Milksnake Lampropeltis triangulum triangulum  
Coastal Plain Milksnake, photo courtesy of Corey Wickliffe Coastal Plain Milksnake Lampropeltis triangulum elapsoides X triangulum  

Northern Scarletsnake, photo courtesy of John White

Northern Scarletsnake Cemophora coccinea copei Watchlist

A number of documents were used to compile the snake descriptions that follow. The document that provided the most information was The Reptiles of Virginia by Joseph C. Mitchell (1994). Amphibians and Reptiles of Pennsylvania by Arthur C. Hulse, C. J. McCoy, and Ellen Censky (2001) and Amphibians and Reptiles of Delmarva by James F. and Amy Wendt White (2002) were also extremely useful. These books are recommended to anyone seeking more comprehensive information on North American snake ecology and identification.

In addition to physical descriptions of snakes, maps depicting the distribution of each snake species in Maryland are also included. The distribution maps include historical distributional information that was compiled by Harris (1975) and distributional surveys of select species by Thompson (1984). White and White (2002) provided a great deal of distributional information for snakes on Maryland’s eastern shore. Additional recent distribution information was provided by the Maryland Department of Natural Resources, Maryland Biological Stream Survey and Natural Heritage Program, and from additional literature where appropriate.

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and Reptile Atlas Project

"A Joint Project of the Natural History Society of Maryland, Inc. and the Maryland Department of Natural Resources"

For monthly newsletters of the Maryland Amphibian & Reptile Atlas Project click on Recent Newsletters and scroll down to the MARA Newsletters.

The Maryland Herpetology Field Guide is a cooperative effort of the MD Natural Heritage Program and the MD Biological Stream Survey within the Department of Natural Resources and their partners. We wish to thank all who contributed field records, text, and photographs, as well as support throughout its development.