''Hypsiglena'' is a genus of small,

rear-fanged A snake skeleton consists primarily of the skull, vertebrae, and ribs, with only vestigial remnants of the limbs. Skull The skull of a snake is a very complex structure, with numerous joints to allow the snake to swallow prey far larger than i ...

, colubrid snakes commonly referred to as night snakes. The genus consists of nine species, and

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

have been maintained pending further investigation.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.

Species and subspecies

The following species and

are recognized as being valid. *'' Hypsiglena affinis''

Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858–1 ...

, 1894 - Boulenger's night snake *''

Hypsiglena catalinae ''Hypsiglena catalinae'', the Isla Santa Catalina night snake, is a species of snake in the family Colubridae. The species is native to Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern ...

'' W.W. Tanner, 1966 - Santa Catalina night snake *''

Hypsiglena chlorophaea ''Hypsiglena chlorophaea'', the desert night snake, is a species of snake in the family Colubridae. The species is native to Mexico, Canada, and the United States The United States of America (U.S.A. or USA), commonly known as the Unite ...

'' Cope, 1860 -

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

n night snake **''

Hypsiglena chlorophaea deserticola ''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.Mulcahy DG, Martínez-Gómez JE, Aguirre ...

'' W.W. Tanner, 1966 - desert night snake **''

Hypsiglena chlorophaea loreala ''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.Mulcahy DG, Martínez-Gómez JE, Aguirr ...

'' W.W. Tanner, 1944 - Mesa Verde night snake **''

Hypsiglena chlorophaea tiburonensis ''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.Mulcahy DG, Martínez-Gómez JE, Aguirr ...

'' W.W. Tanner, 1981 - Tiburón Island night snake *'' Hypsiglena jani'' ( Dugès, 1865) -

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

night snake **''

Hypsiglena jani texana ''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.Mulcahy DG, Martínez-Gómez JE, Aguirr ...

Stejneger Leonhard Hess Stejneger (30 October 1851 – 28 February 1943) was a Norwegian-born American ornithologist, herpetologist and zoologist. Stejneger specialized in vertebrate natural history studies. He gained his greatest reputation with reptiles ...

, 1893 - Texas night snake **''

Hypsiglena jani dunklei ''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.Mulcahy DG, Martínez-Gómez JE, Aguirr ...

'' Taylor, 1938 - Tamaulipas night snake *''

Hypsiglena ochrorhynchus ''Hypsiglena ochrorhynchus'', also known commonly as the coast night snake and the spotted night snake, is a species of snake in the subfamily Dipsadinae of the family Colubridae. The species is native to California in the United States and to ...

'' Cope, 1860 - spotted night snake **''

Hypsiglena ochrorhynchus baueri ''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.Mulcahy DG, Martínez-Gómez JE, Aguirre ...

'' Zweifel, 1958 - Cedros Island night snake **'' Hypsiglena ochrorhynchus gularis'' W.W. Tanner, 1954 -

Isla Partida Isla Partida is separated from Isla Espíritu Santo by a shallow, narrow channel. These two islands, in the Gulf of California, are protected by UNESCO as biospheres. They are located a short boat ride from La Paz, which lies on the Baja Califo ...

night snake **'' Hypsiglena ochrorhynchus klauberi'' W.W. Tanner, 1944 - San Diego night snake **'' Hypsiglena ochrorhynchus martinensis'' W.W. Tanner & Banta 1962 - San Martín Island night snake **'' Hypsiglena ochrorhynchus nuchalata'' W.W. Tanner, 1943 -

California night snake The California night snake (''Hypsiglena ochrorhynchus nuchalata'') is a subspecies of small colubrid snake native to California.ITIS (Integrated Taxonomic Information System). www.itis.gov. Description The California night snake grows to a tot ...

**'' Hypsiglena ochrorhynchus tortugaensis'' W.W. Tanner, 1944 - Isla Tortuga night snake **''

Hypsiglena ochrorhynchus venusta ''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.Mulcahy DG, Martínez-Gómez JE, Aguirre ...

'' Mocquard, 1899 - Central Baja night snake *''

Hypsiglena slevini ''Hypsiglena slevini'', the Baja California night snake, is a species of snake in the family Colubridae. The species is native to Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion ...

'' W.W.Tanner, 1943 - Baja California night snake *''

Hypsiglena tanzeri ''Hypsiglena tanzeri'', the Rio Verde night snake or Tanzer's night snake, is a species of snake in the family Colubridae. The species is native to Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in th ...

Dixon Dixon may refer to: Places International * Dixon Entrance, part of the Inside Passage between Alaska and British Columbia Canada * Dixon, Ontario United States * Dixon, California * Dixon, Illinois * Dixon, Greene County, Indiana * Dixon, Indi ...

& Lieb, 1972 - Tanzer's night snake *'' Hypsiglena torquata'' ( Günther, 1860) -

Sinaloa Sinaloa (), officially the Estado Libre y Soberano de Sinaloa ( en, Free and Sovereign State of Sinaloa), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. It is d ...

night snake *''

Hypsiglena unaocularus ''Hypsiglena unaocularus'', commonly known as the Islas Revillagigedo night snake or Clarión night snake, is a species of small colubrid snake endemic Endemism is the state of a species being found in a single defined geographic location, ...

'' W.W.Tanner, 1946 - Islas Revillagigedo night snake '' Nota bene'': A binomial authority or trinomial authority in parentheses indicates that the species or subspecies was originally described in a genus other than ''Hypsiglena''.

Geographic range

''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.

Habitat

The preferred habitat of night snakes is semiarid

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

regions with rocky and sandy soils.

Description

Night snakes typically do not exceed a total length (including tail) of . They are slender-bodied with a flattened head, and have small

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

s 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.

Behavior

''Hypsiglena'' are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

and terrestrial.

Diet

The diet of night snakes consists primarily of

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s, but they will also consume smaller snakes, and

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

Venom

The venom of ''Hypsiglena'' is not considered to be dangerous to humans.

References

External links

* {{Taxonbar, from=Q3022965 Colubrids Vertebrates of Mexico Reptiles of the United States Snake genera Taxa named by Edward Drinker Cope