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A Checklist of the Snakes of Medina County, Texas


Gerald Keown

This checklist was originally published by the author in 1978. It was a result of extensive field work done by the author in Medina County from 1975 through 1977. The taxonomic status of all species listed have also been updated to reflect common and scientific names currently in use.

Medina County, located west of San Antonio on the edge of the Texas Hill Country encompasses 1352 square miles. The south part of the county consists of fertile valleys and rolling prairies while the north end of the county is scenic hills. The county is between 600 and 1,900 feet above sea level and has an average annual rainfall of approximately 29 inches. Medina Lake is situated in the northeast part of the county, while the Medina River flows through the eastern side of the county. The county has an estimated 40,000 acres in irrigated agricultural use.

The following checklist contains 37 species that are known to occur and unless otherwise noted have been collected in the county by the author. There are an additional 8 species that are known to occur in adjacent counties and that could be expected to possibly occur in Medina County. One species occuring in Medina County is protected under current state law.

South Texas Blind Snake, Leptotyphlops dulcis rubellum

Diamondback Water Snake, Nerodia rhombifer rhombifer

Blotched Water Snake, Nerodia erythrogaster transversa *

Checkered Garter Snake, Thamnophis marcianus marcianus

Eastern Blackneck Garter Snake, Thamnophis cyrtopsis ocellatus

Redstripe Ribbon Snake, Thamnophis proximus rubrilineatus

Texas Garter Snake, Thamnophis sirtalis annectens * * *

Texas Brown Snake, Storeria dekayi texana

Eastern Hognose Snake, Heterodon platirhinos

Rough Green Snake, Opheodrys aestivus

Western Coachwhip, Masticophis flagellum testaceus

Schott's Whipsnake, Masticophis schotti schotti

Central Texas Whipsnake, Masticophis taeniatus girardi

Yellowbelly Racer, Coluber constrictor flaviventris *

Texas Indigo Snake, Drymarchon melanurus erebennus  (Protected Species)

Texas Patchnose Snake, Salvadora grahamiae lineata

Texas Glossy Snake, Arizona elegans arenicola *

Bull Snake, Pituophis catenifer sayi

Western Rat Snake, Elaphe obsoletus

Northern Plains Rat Snake, Elaphe emoryi emoryi x meahllmorum

Baird's Rat Snake, Elaphe bairdi

Mexican Milk Snake, Lampropeltis triangulum annulata *

Desert Kingsnake, Lampropeltis getula splendida

Prairie Ringneck Snake, Diadophis punctatus arnyi

Ground Snake, Sonora semiannulata semiannulata x taylori

Rough Earth Snake, Virginia striatula

Texas Longnose Snake, Rhinocheilus lecontei tessellatus

Flathead Snake, Tantilla gracilis

Plains Blackhead Snake, Tantilla nigriceps

Southwestern Blackhead Snake, Tantilla hobartsmithi

Texas Night Snake, Hypsiglena torquata jani *

Texas Coral Snake, Micrurus tener tener * *

Broad-Banded Copperhead, Agkistrodon contortrix laticinctus * *

Western Cottonmouth, Agkistrodon piscivorus leucstoma * *

Western Diamondback Rattlesnake, Crotalus atrox * *

Northern Black-Tailed Rattlesnake, Crotalus molossus molossus * *

Mottled Rock Rattlesnake, Crotalus lepidus lepidus * *


 *     = Based upon a literature record only.

 * *   = Venomous species.

 * * * = Known in the county from a single voucher specimen (TCWC ID#14883) in the Texas Cooperative
           Wildlife Collection at Texas A & M University. Collected 03 May 1957.


Brown, Bryce C. 1950. An Annotated Check List of the Reptiles and Amphibians of Texas. Baylor University Press, Waco.

Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America, 2nd edition. Houghton Mifflin, Co., Boston.

Dixon, James R. 2000. Amphibians and Reptiles of Texas, 2nd edition. Texas A & M Press, College Station.

Werler, John E., and James R. Dixon. 2000. Texas Snakes, Identification, Distribution and Natural History. University of Texas Press, Austin.

Date submitted 02/28/07

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