Hypsiglena is a genus of small, rear-fanged, colubrid snakes commonly referred to as night snakes. The genus consists of nine species, and subspecies have been maintained pending further investigation.
Species and subspecies
- Hypsiglena affinis Boulenger, 1894 - Boulenger's night snake
- Hypsiglena catalinae W.W. Tanner, 1966 - Santa Catalina night snake
- Hypsiglena chlorophaea Cope, 1860 - Sonoran night snake
- Hypsiglena jani (Dugès, 1865) - Chihuahua night snake
Hypsiglena ochrorhyncha Cope, 1860 - spotted night snake
- Hypsiglena ochrorhyncha baueri Zweifel, 1958 - Cedros Island night snake
- Hypsiglena ochrorhyncha gularis W.W. Tanner, 1954 - Isla Partida night snake
- Hypsiglena ochrorhyncha klauberi W.W. Tanner, 1944 - San Diego night snake
- Hypsiglena ochrorhyncha martinensis W.W. Tanner & Banta 1962 - San Martín Island night snake
- Hypsiglena ochrorhyncha nuchalata W.W. Tanner, 1943 - California night snake
- Hypsiglena ochrorhyncha tortugaensis W.W. Tanner, 1944 - Isla Tortuga night snake
- Hypsiglena ochrorhyncha venusta Mocquard, 1899 - Central Baja night snake
- Hypsiglena slevini W.W.Tanner, 1943 - Baja California night snake
- Hypsiglena tanzeri Dixon & Lieb, 1972 - Tanzer's night snake
- Hypsiglena torquata (Günther, 1860) - Sinaloa night snake
- Hypsiglena unaocularus W.W.Tanner, 1946 - Islas Revillagigedo night snake
Hypsiglena are found throughout the southwestern and western United States, from Texas and Kansas, west to California, north to Washington, and south into Mexico, as well as on islands off the coasts of Mexico.
Night snakes typically do not exceed a total length (including tail) of 40 cm (16 in). They are slender-bodied with a flattened head, and have small eyes with vertical pupils. Their color varies depending on their locality, often matching the soil color of their native habitat. They occur in various shades of gray, and brown, with dark brown, gray or black blotches on the back and the sides. Many also have distinctive black markings on the neck region.
The venom of Hypsiglena is not considered to be dangerous to humans.
- ^ Tanner WW (1944). "A Taxonomic Study of the Genus ' 'Hypsiglena ". Great Basin Naturalist 5 (3 & 4): 25-92.
- ^ Mulcahy DG (2008). "Phylogeography and species boundaries of the western North American nightsnake (Hypsiglena torquata): Revisiting the subspecies concept". Molecular Phylogenetics and Evolution 46 (3): 1095–1115.
- ^ Mulcahy DG, Martínez-Gómez JE, Aguirre-León G, Cervantes-Pasqualli JA, Zug GR (2014). "Rediscovery of an endemic vertebrate from the remote Islas Revillagigedo in the eastern Pacific Ocean: The Clarión Nightsnake, with conservation and systematic implications". PLOS ONE 9 (5): e97682.