Is the Chihuahuan Nightsnake venomous?

The Chihuahuan Nightsnake (Hypsiglena jani) is rear-fanged and only mildly venomous. It is not considered dangerous to humans (its venom is weak and its fangs sit at the back of the mouth) but a bite can cause local swelling or irritation, so it should not be handled.

Is the Chihuahuan Nightsnake poisonous?

Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Chihuahuan Nightsnake is neither poisonous nor venomous.

Is the Chihuahuan Nightsnake dangerous?

The Chihuahuan Nightsnake is not dangerous to humans. It has no medically significant venom and bites only defensively if cornered or handled.

Where does the Chihuahuan Nightsnake live?

The Chihuahuan Nightsnake has verified records in 2 countries, including United States of America, Mexico. See the distribution section below for its full range.

How do I identify the Chihuahuan Nightsnake?

Pale gray with dark blotches, vertical pupils, and dark neck blotches.

Nightsnake

Chihuahuan Nightsnake

Harmless

Hypsiglena jani

Chihuahuan Nightsnake — Hypsiglena jani, © Reid Hardin

6 photographs of the Chihuahuan Nightsnake. © Reid Hardin.

The Chihuahuan Nightsnake (Hypsiglena jani) is a rear-fanged, mildly venomous snake in the Colubridae family, recorded in 2 countries.

Also called: Nightsnake
Family: Colubridae
Size: Small, 12–26 in.
Habitat: Arid and semi-arid rocky areas.
Behavior: Nocturnal; rear-fanged but harmless to humans.
Identify: Pale gray with dark blotches, vertical pupils, and dark neck blotches.

About the Chihuahuan Nightsnake

Hypsiglena jani, commonly known as the Texas night snake or the Chihuahuan night snake, is a small species of mildly venomous snake in the subfamily Dipsadinae of the family Colubridae. The species is native to the southwestern United States and adjacent northeastern Mexico.

Etymology

The epithet, jani, is in honor of Italian taxonomist Giorgio Jan.

Description

H. jani grows from 10 to 16 inches (25 to 41 centimetres) in total length (including tail), record 20 inches (51 cm). It is typically a light gray or tan in color, with dark brown or dark gray blotching down the back, and has an unmarked underside. It has smooth dorsal scales. The eye has a vertically elliptical pupil. H. jani is rear-fanged, and is considered to be venomous, though it is not dangerous to humans.

Behavior

As the common names imply, H. jani is a primarily nocturnal snake.

Diet

The diet of H. jani consists of primarily lizards, but it will also eat smaller snakes and occasionally soft bodied insects.

Habitat

H. jani prefers semi-arid habitats with rocky soils.

Reproduction

H. jani is an oviparous species that breeds in the spring rainy season, laying 4–6 eggs that take approximately 8 weeks to incubate before hatching. The eggs average 27 mm (1.1 in) long by 10 mm (3⁄8 in) wide. The hatchlings are about 15 cm (5.9 in) in total length.

Geographic range

H. jani ranges from southern Kansas to southern Colorado, and south throughout New Mexico, the western half of Texas to central Mexico.

Subspecies

Three subspecies are recognized as being valid, including the nominotypical subspecies.

Hypsiglena jani dunklei Taylor, 1938

Hypsiglena jani jani (Dugès, 1865)

Hypsiglena jani texana Stejneger, 1893

Nota bene: A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than Hypsiglena.

Adapted from Wikipedia, available under CC BY-SA.

Frequently asked: Chihuahuan Nightsnake

Is the Chihuahuan Nightsnake venomous?: The Chihuahuan Nightsnake (Hypsiglena jani) is rear-fanged and only mildly venomous. It is not considered dangerous to humans (its venom is weak and its fangs sit at the back of the mouth) but a bite can cause local swelling or irritation, so it should not be handled.
Is the Chihuahuan Nightsnake poisonous?: Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Chihuahuan Nightsnake is neither poisonous nor venomous.
Is the Chihuahuan Nightsnake dangerous?: The Chihuahuan Nightsnake is not dangerous to humans. It has no medically significant venom and bites only defensively if cornered or handled.
Where does the Chihuahuan Nightsnake live?: The Chihuahuan Nightsnake has verified records in 2 countries, including United States of America, Mexico. See the distribution section below for its full range.
How do I identify the Chihuahuan Nightsnake?: Pale gray with dark blotches, vertical pupils, and dark neck blotches.
How big does the Chihuahuan Nightsnake get?: Small, 12–26 in.
What does the Chihuahuan Nightsnake eat?: The diet of H. jani consists of primarily lizards, but it will also eat smaller snakes and occasionally soft bodied insects.
Why is it called the Chihuahuan Nightsnake?: The epithet, jani, is in honor of Italian taxonomist Giorgio Jan.

Where it is found

United States of America Mexico

By U.S. state

Texas New Mexico Oklahoma Arizona Colorado Kansas

More Colubridae snakes

Classification

How scientists group this snake, from the broadest category down to the exact species. Each step narrows to its closest relatives.

OrderThe broad group of scaled reptiles: all snakes and lizards: Squamata
FamilyA group of related snakes that share key traits: Colubridae
GenusA close-knit group of very similar species: Hypsiglena
SpeciesThis exact snake, named in the two-part scientific name: Hypsiglena jani

Keep learning

Distribution from GBIF & iNaturalist. Venom status per CDC. Background: Wikipedia. Informational only. Never handle a snake to identify it.