Official Site of the Aransas National Wildlife Refuge Complex

Amphibians and Reptiles of Aransas NWR Complex

AMPHIBIANS

Amphibians have moist, glandular skins, and their toes are devoid of claws. Their young pass through a larval, usually aquatic, stage before they metamorphose into the adult form. Belonging to the Class Amphibia are the salamanders, frogs, and toads.

Salamanders
	Rio Grande Lesser Siren (Siren intermedia siren). These black, eel-like salamanders are usually seen in ditches and shallow ponds during warm spring rains.
	Small-mouthed Salamander (Ambystoma texanum). This, and the species below, occur underground or beneath leaves or logs as adults. The small-mouthed salamander has been collected only once, in 1981.
	Eastern Tiger Salamander (Ambystoma tigrinum tigrinum). Beautifully marked in black and orange stripes, this salamander is seldom reported at Aransas.
Toads and Frogs
	Blanchard’s Cricket Frog (Acris crepitans blanchardi). Though members of the treefrog family, cricket frogs are non-climbers. The call of this species resembles the clicking of pebbles.
	Green Treefrog (Hyla cinerea). Sucker-like discs on their toes enable them to climb and cling to almost any surface. Despite the name, this species can change to solid brown depending on its immediate environment. These frogs can often be seen clinging to cattails. Calls include a harsh, barking sound.
	Squirrel Treefrog (Hyla squirella). Like the former species, the squirrel treefrog can change color from brown to green and from plain to spotted. Its name comes from its harsh, squirrel-like croak.
	Spotted Chorus Frog (Pseudacris clarki). When you hear what sounds like a comb when someone runs a finger down its teeth, you are hearing the mating call of this small, green-spotted frog.
	Strecker’s Chorus Frog (Pseudacris streckeri). Fairly common, heard most often in mid-winter. This frog has a high, clear, whistled call note, often in chorus. Heard, among other places, at Thomas Slough and Jones Lake.
	Couch’s Spadefoot (Scaphiopus couchi). Spadefoot toads use the black “spades” of their hind feet to burrow underground where they may stay for weeks at a time. Damp weather brings them out, when their bleating sheep-like calls may be heard. Call notes last for ½ to 1 second.
	Hurter’s Spadefoot (Scaphiopus hurteri). This spadefoot has a “boss,” or hump, between the eyes and elongated, sickle-shaped spades. Its shorter call note lasts for less than ½ second.
	Texas Toad (Bufo speciosus). This chubby gray toad has yellow-green or brown spots and pink, orange, or greenish warts.
	Gulf Coast Toad (Bufo valliceps valicepts). Probably our most common toad, it is readily identified by a dark, lateral stripe.
	Eastern Narrow-mouthed Toad (Gastrophryne carolinensis). Narrow-mouthed toads can be identified by their pointed heads and plump bodies. They often run, rather than hop, when making an escape, and their calls resemble an electric buzz. This one can be distinguished by its highly mottled underside.
	Great Plains Narrow-mouthed Toad (Gastrophryne olivacea). Favoring ants, this toad is sometimes called the “ant-eating toad.” It has a plain underside.
	Bullfrog (Rana catesbeiana). Its loud, groaning call (“jug-o’-rum, jug-o’-rum”) can be heard around Thomas Slough and Jones Lake both day and night. This is the largest amphibian at Aransas.
	Southern Leopard Frog (Rana utricularia). You may be familiar with this common species from biology class, because leopard frogs are often used as study specimens. Listen for the chuckle-like call of this dark, spotted frog, and look for it along Heron Flats trail.

REPTILES

Reptiles are clad in scales, shields, or plates, and their toes bear claws. To this class belong the crocodilians, lizards, snakes, and turtles.

Crocodilians
	American Alligator (Alligator mississipiensis). A native of the Texas coast and resident of lakes, rivers, and marshes, the alligator is common throughout the Refuge. Once endangered in Texas, the status of this large reptile is now “threatened,” and the animal is making a comeback in many areas of the state. Although it lives in fresh water, the alligator can sometimes be seen feeding in the bays. In the spring, the males can often be heard “bellowing” their mating calls.
Turtles
	Common Snapping Turtle (Chelydra serpentina serpentina). Habitats preferred are freshwater ponds but may enter brackish water. When on land, they become aggressive.
	Yellow Mud Turtle (Kinosteron flavescens flavescens). Mud turtles prefer ponds or lakes with muddy bottoms and often appear along roadsides foraging for food. When handled, they give off a strong, musky odor.
	Texas Diamondback Terrapin (Malaclemys terrapin littoralis). Usually associated with salt water and characterized by a black mustache on the upper jaw and raised centers to its scutes (back scales). This turtle is sometimes seen along the bay shores or in the shallow waters by fishermen.
	Ornate Box Turtle (Terrapene ornata ornata). Yellow lines radiate down the sides of the dark carapace of this land turtle. Box turtles appear after rainstorms.
	Red-eared Slider (Trachemys scripta elegans). Our most commonly seen turtle, it is characterized by a reddish-orange stripe on the side of its face. Many are seen in the spring and summer when the turtles mate and the females bury their eggs. These species are “basking turtles,” and can sometimes be seen along the Rail Trail, sitting in the sun on the bank or on logs.
	Guadalupe Spiney Soft-shell Turtle (Apalone spiniferus guadalpensis). White spots and a white border on the dark leathery back identify this pointy-nosed, freshwater species.
	Loggerhead (Caretta caretta). The back of the shell of the species is reddish-brown and heart shaped while the bottom is a cream yellow. Coastal bays, lagoons, estuaries, and open waters are preferred.
	Atlantic Green (Chelonia mydas mydas). These turtles have an olive to brown, oval shaped shell. Shallow waters with plenty of vegetation as cover is preferred.
	Atlantic Hawksbill ( Eretmochelys imbricata imbricata). Found in shallow waters, the hawksbill has a greenish-brown shell with a mottled pattern. It also has a keel down the middle and overlapping scutes.
	Atlantic Ridley (Lepidochelys kempi). This highly endangered species has a heart shaped, keeled shell that is grayish-green in color. They prefer shallow coastal waters and are extremely carnivorous.
	Leatherback (Dermochelys coriacea). The largest living turtle today, adults can weigh between 600 and 1,600 pounds. These turtles have an elongated oval shell that is covered in a slate blue skin and has 7 ridges. They inhabit open seas, bays and estuaries.
Note on Sea Turtles:
Five species, the Green, Hawksbill, Atlantic Ridley, Loggerhead, and Leatherback, occur in the Gulf of Mexico, and occasionally are found in the bay system. Since all five species are endangered, any sea turtle observed, dead or alive, should be reported to Refuge personnel. Identification brochures are available at the Refuge visitor center.
Lizards
	Mediterranean Gecko (Hemidactylus turcicus turcicus). An introduced species which is apparently found only in and around buildings on the Refuge. Can sometimes be found in the restrooms at the visitor center! This species can be distinguished from other lizards by the lack of eyelids.
	Texas Horned Lizard (Phyrnosoma cornutum). Commonly associated with the arid sections of the U.S., horned lizards are insect eaters, especially ants, and need high temperatures to stimulate their diets. Suited to more upland, dry habitats than generally exist at Aransas, they are thus rather restricted in their occurrence.
	Northern Fence Lizard (Sceloporus undulatus hyacinthinus). This is a rather common, tree-climbing lizard.
	Green Anole (Anolis carolinensis). An arboreal insect eater, the anole is often sold in pet shops as a “chameleon” because of its ability to change from green to brown as its surroundings change. Males often respond to territorial threats by expanding their pinkish throat pouches.
	Ground Skink (Scincella lateralis). Its legs are quite reduced, giving this lizard a snake-like appearance, though it is usually less than four inches long. It is deep brown in color, and found in decaying leaves and other plant matter in woodland areas.
	Texas Spotted Whiptail (Cnemidophorus gularis gularis). This lizard is not numerous at Aransas, being restricted mainly to the drier upland areas in the west portions of the Refuge. Similar to the former species, except that rows of spots occur between the back stripes.
	Six-lined Race Runner (Cnemidophorus sexlineatus sexlineatus). Also known as whiptails, racerunners are often found in open areas at ground level (never in trees). These are commonly observed dashing in quick spurts ahead of you on the trail, where you may get a glimpse of the boldly-striped back.
	Western Slender Glass Lizard (Ophisaurus attentuatus). Unique among North American lizards, this reptile is legless and is often mistaken for a snake. Glass lizards, however, have closable eyelids, whereas snakes at Aransas do not. An unusual defense mechanism enables the glass lizard to disjoint all or part of its tail (hence the name “glass”), gaining it an opportunity to escape a confused captor. Glass lizards are fairly common at Aransas; look for these snake-like creatures, with a series of longitudinal brown stripes, sunning themselves on the road pavement.
Snakes
	Texas Blind Snake (Leptotyphlops dulcis). So small is this subterranean dweller that it is seldom noticed. Pinkish in color and with only vestigial eyes, it is sometimes found in overturned earth or under logs.
	Texas Scarlet Snake (Cemophora coccinea lineri). Here is another species that resembles the coral snake, but it has a red snout, while the coral’s is black. It is seldom seen above ground and feeds on young mice, lizards, and snakes.
	Eastern Yellow-bellied Racer (Coluber constrictor flaviventris). A long, slender, fast-moving snake often seen foraging during the day. It is grayish green on the back, and yellowish on the belly. Young are often seen, and they are whitish with a series of large, brownish blotches.
	Mexican Racer (Coluber constrictor oaxaca). This subspecies of the eastern yellow-bellied can be distinguished mainly by the number of its labial (lip) scales.
	Southwestern Rat Snake (Elaphe guttata meahllmorum). This species is smaller than the one above, and it has a patterned head, with one patch of brown forming a spear point between the eyes. It is primarily nocturnal, but like many other species can sometimes be seen on the roads after rains and/or during the evening or morning hours.
	Texas Rat Snake (Elaphe obsoleta lindheimeri). One of the largest snakes at Aransas, the Texas rat snake can attain the length of almost six feet. It is notorious for robbing nests of eggs. It can be distinguished from the species below by its blackish head.
	Western Mud Snake (Farancia abacura reinwardti). It is by far the most beautiful snake in our area, with its shiny black dorsum and salmon-pink belly. Mud snakes feed chiefly on the lesser siren. Famed as the “hoop snake” and the “stinging snake,” its reputation comes from folklore, not fact. When alarmed, the snake often turns its head toward its body and becomes rigid—it does not roll into a hoop and travel in that manner. It also has a point on the end of its tail, and although somewhat sharp, does not have a stinger.
	Eastern Hognose Snake (Heterodon platirhinos). To bluff intruders, the harmless hognose or “puff adder” puts on quite a show to make its target think otherwise. First, it flattens its head and hisses, and if that doesn’t work, it goes into convulsions. Finally, it rolls over on its back and pretends to be dead. This ruse hides the fact that the snake is actually very docile.
	Dusky Hognose Snake (Heterodon nasicus gloydi). Look for the sharply unturned snout on hognose snakes. The mainstay of this and the above species is toads. This species is generally lighter in color than the eastern.
	Prairie King Snake (Lampropeltis calligaster calligaster). A grassland resident, this kingsnake may be troublesome to identify because of its resemblance to (especially) the Southwestern rat snake. However, the prairie kingsnake has smooth scales, while the rat snake’s are keeled (like the middle of a boat hull).
	Speckled Kingsnake (Lampropeltis getula holbrooki). Yellow spots on a black background (a “salt and pepper” pattern) make this species easy to identify. Kingsnakes are noted for feeding on other snakes, including poisonous species.
	Desert Kingsnake (Lampropeltis getula splendida). This large dark snake favors arid areas near a reliable water source. Adults range in size from 36 to 45 inches in length, with the record for this species at 60 inches. This species is extremely rare on the Refuge; the only known sighting was in 2004.
	Desert King Snake (Lampropeltis getula splendida). This variety of the speckled kingsnake is similar but the yellow spots form distinct, lateral stripes on the back.
	Louisiana Milk Snake (Lampropeltis triangulum amaura). Color patterns of this kingsnake are similar to those of the poisonous coral snake. However, the milk snake has black bordering red in the color pattern rather than red bordering yellow as in the coral snake.
	Western Coachwhip (Masticophis flagellum testaceus). This unicolored to blotched snake has a braided, or whip-like, appearance. It is an extremely fast-moving snake and can be very aggressive.
	Gulf Salt Marsh Snake (Nerodia clarki clarki). This striped water snake occurs almost exclusively in salt-water habitat. Its markings are similar to those of the garter snake.
	Green Water Snake (Nerodia cyclopion cyclopion). General coloration is green or brown with a belly marked by light half-moon-shaped spots.
	Broad-banded Water Snake (Nerodia fasciata confluens). A single specimen of this snake was found along the Refuge tour road in 1981.
	Diamond-backed Water Snake (Nerodia rhombifer rhombifer). This large, rough-scaled water snake is much maligned because of its similarity to the poisonous cottonmouth. It will usually take to water immediately after being approached or threatened.
	Rough Green Snake (Opheodrys aestivus). This fragile-looking, pale green snake is a good climber and is often mistaken for a vine or tree branch. Green snakes prefer wooded areas, but are often seen on Refuge roads.
	Bullsnake (Pituophis catenifer sayi). The status of this species at Aransas is not well known, but one specimen was found in 1974. It is a distinct, often very large snake, with a pattern of dark brown blotches over a cream-colored background. Its tail also has dark brown rings.
	Graham’s Crayfish Snake (Regina grahami). A dark back, usually black and lighter longitudinal stripes on the sides give this snake a distinctive color pattern. Prey consists of crayfish and other crustaceans.
	Texas Brown Snake (Storeria dekayi texana). Its small size, brown coloration, and two rows of black spots on the belly make this snake distinctive. Brown snakes are often found in populated areas around cemeteries, flower beds, etc.
	Flatheaded Snake (Tantilla gracilis). Eight inches is usually the maximum length of this brown, worm-like snake, which is normally found living under logs or other debris.
	Checkered Garter Snake (Thamnophis marcianus marcianus). Markings include a checkerboard pattern superimposed on faint, longitudinal stripes. Crayfish, tadpoles, minnows, and frogs constitute the bulk of its prey.
	Gulf Coast Ribbon Snake (Thamnophis proximus orarius). Found around marshy areas, this snake is probably our most commonly seen species, often seen sunning itself on the roadways. It is olive with yellow longitudinal stripes.
	Red-sided Garter Snake (Thamnophis sirtalis parietalis). This snake is similar to our ribbon snake, but has a considerably broader orange stripe along its back.
	Eastern Garter Snake (Thamnophis sirtalis sirtalis). Back and side stripes usually well-defined. Red blotches or a double row of alternating black spots often present between stripes.
	Rough Earth Snake (Virginia striatula). Its length rarely exceeds 10 inches. This secretive, nondescript reptile is usually found under boards and logs. The head is cone-shaped and the color is solid light brown.
Poisonous Snakes
NOTE: Many species of snakes will bite, but usually only in circumstances in which they are threatened. This includes when they are handled, if they are cornered, threatened, or all of the above. The best way to avoid snake-bites is to watch where you step and to not handle them. Otherwise, by keeping a distance from them, snakes can be fascinating creatures to watch. If you think you have been bitten by a poisonous snake, the best treatment is to remain calm and at rest, and then to get to a medical facility as soon as possible. You will have a few hours as a buffer zone before the wound becomes critical. If you are bitten at Aransas, proceed immediately to the headquarters so that Refuge personnel can quicken your trip to a medical facility. If you are not sure what kind of snake has bitten you, it is best to play it safe and assume the snake was poisonous.
	Texas Coral Snake (Micrurus fulvius tenerx). “Red and yellow is a venomous fellow” is the best way to remember the color pattern of this snake, which is a pretty series of black, yellow, and red bands. None of the “mimic” snakes mentioned earlier have the red and yellow bordering each other. Coral snakes are highly poisonous, but are rather docile and shy. They are not often seen, spending most of their time below the surface, and can reach more than two feet in length. Coral snakes are members of the cobra family.
	Broad-banded Copperhead (Agkistrodon contortix laticinctus). The color pattern is coppery, and this species is rare at Aransas. Copperheads, cottonmouths, and rattlesnakes are termed “pit vipers” because of special heat-sensing organs, or “pits,” located between the nostrils and eyes. These organs are valuable in detecting the presence of prey.
	Western Cottonmouth (Agkistrodon piscivorus leucostoma). This is our most commonly seen poisonous snake. When alarmed, the cottonmouth will threateningly open its mouth wide, exposing white mouth parts, hence its name. Older specimens are often almost solid brownish-black on the back.
	Western Massasauga (Sistrurus catenatus tergeminus). This rattlesnake of the swamps and bogs has a pattern of large, black blotches down the back. It is not seen very often at Aransas.
	Western Diamondback Rattlesnake (Crotalus atrox). A well-known and often feared snake, this rattlesnake is seen occasionally around higher areas, such as dunes and shell mounds. This snake usually lets you know it’s there by its rattle (actually more like a buzz). It is named for the prominent pattern of diamond-shape blotches on its back, and it feeds primarily on rodents.

Although a positive sighting or identification has not happened, the following list of species could possibly occur on Refuge land due to recent land acquisitions.

Frogs
	Gray Tree Frog (Hyla versicolor)
	Upland Chorus Frog (Pseudacris triseriata feriarum)
	Eastern Green Toad (Bufo debilis debilis)
	Woodhouse's Toad (Bufo woodhousii woodhousii)
	Rio Grande Leopard Frog (Rana berlandieri)
Turtles
	Mississippi Mud Turtle (Kenosternon subrubrum hippocrepis)
	Stinkpot (Sternotherus odoratus)
	Three-toed Box Turtle (Terrapene carolina triunguis)
Lizards
	Southern Earless Lizard (Holbrookia lacerate subcaudalis)
	Keeled Earless Lizard (Holbrookiia propinqua propinqua)
	Texas Spiny Lizard (Sceloporus olivaceus)
	Southern Prairie Lizard (Sceloperus undulates consobrinus)
	Five-lined Skink ( Eumeces fasciatus)
	Southern Prairie Skink (Eumeces septentrionalis obtusirostris)
Snakes
	Texas Glossy Snake (Arizona elegans arenicola)
	Texas Indigo Snake (Drumarchon corais erebennus)
	Schott's Whip Snake (Masticophis schotti schotti)
	Blotched Water Snake (Nerodia erythrogaster transversa)
	Texas Long-nosed Snake (Rhinocheilus lecontei tessellatus)
	Texas Patchnosed Snake (Salvadora grahamiae lineata)
	Plains Blackheaded Snake (Tantilla nigriceps nigriceps)
	Canebrake Rattlesnake (Crotalus horridus atricaudatus)
	Western Pygmy Rattlesnake (Sistrurus miliarius streckeri)

Revision June 2006

Reference:
Dixon, James R. Amphibians and Reptiles of Texas. College Station: University Press, 2000.

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