Hypsiglena jani

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 in in total length (including tail), record 20 in. 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 long by 10 mm wide. The hatchlings are about 15 cm 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.