Snakes

The back half of a snake is visible, with the alternating bands of black and white on the tail, ending in a series of 7 rattles.
Western diamondback rattlesnake tail

NPS/J. Jurado

 
A snake composed of alternating bands of white and rusty red lies comfortably in the grass.
Their venom is mild compared to other venomous snakes

NPS/J. Jurado

Trans-Pecos Copperhead

Agkistrodon contortrix pictagaster
The Trans-Pecos copperhead is a venomous snake, found throughout the park in the proper habitat, which includes springs and the Rio Grande. This subspecies is confined to far West Texas and northeastern Mexico. Newborn copperheads are capable of finding and capturing their own prey at the time of birth. They have a maximum lifespan in the wild of 15-18 years. If threatened, copperheads may vibrate the tip of their tail to mimic a rattlesnake, and will strike if sufficiently threatened. Kingsnakes are reported to be immune to their venom.
 
A pink snake winds in between grasses
Also called a red racer

NPS Photo

Western Coachwhip

Masticophis flagellum testaceus
Preferring desert lowland and scrub lands, the western coachwhip is found from the Rio Grande floodplain to the Chisos Mountains foothills. They are swift and will climb trees and shrubs. One of the fastest snakes in North America, with the ability to turn quickly, coachwhips have few natural predators. When a coachwhip snake bites, they thrash their head from side to side, tearing the skin after puncturing it. Western coachwhips remain active during the middle of the day, which makes them the snake most often seen in the park.
 
a snake with brown diamond-shaped patterns on it back and a black and white banded tail with rattles
Look for the bands of black and white on the tail

NPS/CA Hoyt

Western Diamondback Rattlesnake

Crotalus atrox
This venomous rattlesnake is found in the park from the Rio Grande floodplain up to the foothills of the Chisos Mountains (up to about 4,500 feet). They have a plump body, short tail, and a broad triangular head. Rattlesnakes are good at controlling rodent problems, and will also eat small mammals, birds, fish, and even invertebrates. Western diamondback rattlesnakes are aggressive and easily excitable, and cause more fatalities than any other snake in the United States.
 
A coiled snake with brown diamond patterns on its spine and a white tail with a few thin black bands.
The tail is the key

NPS Photo

Mojave Rattlesnake

Crotalus scutulatus scutulatus
These venomous rattlesnakes are found throughout the park from the Rio Grande floodplain up to about 4,000 feet. Mojave rattlesnakes occupy low, hot deserts, creosote bush flats and grasslands. They are very similar in appearance to western diamondback rattlesnakes, the key difference is in the bands on the tail. Western diamondback rattlesnakes have alternating similiarly-sized bands of black and white, while the Mojave's tail is mostly white with thin black bands.
 
The black tail of a snake with seven rattles on the end.
The solid black tail gives it away

NPS/C. Ballou

Black-tailed Rattlesnake

Crotalus molossus molossus
The black-tailed rattlesnake prefers mountains, canyons, and rock outcrops. They are found park-wide, but are most common in the Chisos Mountains and foothills. This species can climb trees and are also able to swim quickly in water. They communicate threats to their enemies by using three devices. First, they will rattle their tail to startle an aggressor. If this doesn't work, they will then hiss loudly and rapidly flick their tongue, in addition to rattling. Another warning typical of vipers is to puff up and coil their bodies, making them look much larger.
 
A snake with a brown body covered in black blotches
Notice the large triangle-shaped head

NPS/CA Hoyt

Mottled Rock Rattlesnake

Crotalus lepidus lepidus
This venomous snake is found throughout the park, but most commonly in the Chisos Mountains and foothills. They spend most of their lives in rocky outcroppings and talus slopes. Mottled rock rattlesnakes are small compared to other rattlesnakes, rarely exceeding 3 feet in length, but they have a fairly thick body for their size. In general, these rattlesnakes are not aggressive. They tend to rely on their camouflage and will often not strike or even rattle their tails unless physically harassed.
 
A long thin snake of gray coloration with narrow bands of brown.
They can reach 4 feet in length

NPS Photo

Baird's Rat Snake

Pantherophis bairdi
In North America, this snake is found only in portions of central and west Texas, and northern Mexico. Preferring forested uplands, rocky wooded canyons, upland meadows, and shrublands, the Baird's rat snake lives in the Chisos Mountains above 4,000 feet. This rat snake is slow-moving and generally calm, but will hiss and may strike if threatened. It feeds on small mammals, birds and lizards.
 
A thin yellow snake with two parallel black lines running down the back.
Active on hot nights

NPS Photo

Trans-Pecos Rat Snake

Bogertophis subocularis subocularis
This rat snake is a Chihuahuan desert endemic, being found exclusively in New Mexico, the Trans-Pecos region of West Texas, and the state of Chihuahua in Mexico. Within the park, they inhabit the Rio Grande floodplain up to the Chisos Mountains foothills below 5,000 feet. They are non-venomous, instead killing their prey by constriction. Only in rare instances will they defend themselves from humans by biting. Trans-Pecos ratsnakes are usually seen at night crossing roads during the hot months of summer. They retreat to limestone cracks and crevices during the day.
 
A small snake with gray-colored scales on top and red-colored scales underneath near the tail.
Check out the underside of the tail!

NPS Photo

Regal Ring-necked Snake

Diadophis punctatus regalis
This secretive snake inhabits rocky moist areas - under rocks, logs, sotols, and agaves. Within the park it is found mainly in the Chisos Mountains and foothills, rarely seen in other mountains and canyon lowlands along the Rio Grande. When disturbed, it will coil its tail like a corkscrew, exposing the underside which is usually bright red. Small snakes and lizards are probably the most important food sources for this subspecies. Worms, slugs, and insects are also eaten by this species. Its mild venom may help to incapacitate prey, including juvenile California king snakes.
 
A snake with a white belly and alternating bands of red and black on the top.
Has an elongated snout with an upward tilt

NPS Photo

Texas Long-Nosed Snake

Rhinocheilus lecontei tessellatus
Within the park, these snakes are found from the Rio Grande floodplain to the Chisos Mountains and north to the Rosillos Mountains. They prefer desert, creosote and bush flats and can be found resting during the day under rocks, sotol, or in animal burrows. They are active at night, particularly after it rains. The color pattern of the nonvenomous Texas long-nosed snake is vaguely similar to that of a venomous coral snake. In some western localities, the red coloration can be greatly reduced, giving it more of a black and white banded appearance.
 
A long thin snake with dark coloration and white color underneath the head.
One of the most common snakes encountered in the Chisos Mountains

NPS Photo

Central Texas Whipsnake

Masticophis taeniatus girardi
The Central Texas whipsnake is found park-wide except for possibly the highest parts of the Chisos Mountains. Holding its head several inches above the ground to survey its surroundings, the whipsnake glides slowly over the ground, watching intently for prey to dart across its path. This active forager does not restrict its diet to any particular group of animals. It will eat birds and their eggs, lizards, other snakes, and small mammals - even bats! Equipped with a slender, light-weight body, this snake is a proficient climber and can sometimes be found up in trees and bushes, searching for avian prey.
 
A dark snake with small light-colored bands across the top of the body
If attacked they will discharge an odorous musk

NPS/CA Hoyt

Blotched Water Snake

Nerodia erythrogaster transversa
These snakes are semi-aquatic, using both terrestrial and feshwater habitats. Within the park, they are only found along the Rio Grande between Hot Springs and Boquillas Canyon, including the beaver pond at Rio Grande Village. Feeding primarily occurs in or near ephemeral ponds or pools where frogs and toads are abundant. Snakes in this genus will flatten themselves or flee when detected. If cornered, they will strike fiercely. They are known to discharge an odorous musk in self-defense.
 
A thin, but long snake with patches of brown on the spine lies calmly on the ground.
Also known as a bullsnake

NPS Photo

Sonoran Gopher Snake

Pituophis catenifer affinis
The Sonoran gopher snake is found park-wide in desert, shrub lands, and woodland habitats. It is known to sometimes climb trees. When threatened, it can hiss, inflate its body, flatten the head, and shake its tail rapidly, which may sound like a rattle if done in dry leaves. This snake has tough skin on its nose to assist with burrowing into gopher holes. It feeds on small mammals, including gophers; and will eat some birds, as well as lizards. It is a constrictor that kills prey by suffocating them in body coils.

Last updated: August 5, 2020

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