Hypsiglena torquata
Encyclopedia
Hypsiglena torquata is a species
of rear-fanged, colubrid
snake
known as the night snake. They are found through the south and western United States
, as well as Mexico
. The number of subspecies
varies depending on the source, but it is generally accepted that there are 17.
, however the nightsnake's lack of rattles is an easy way to differentiate. Rattlesnakes are, however, born without a rattle. The nightsnake also has a black or dark brown bar behind the eyes that contrast against the white or pale grey upper labial scales. The belly of the nightsnake is white or yellowish and it also has a vertical pupil.
, and as far south as Guerrero, Mexico. The Eastern range of the night snake extends to Texas. Still, not much is known as far as population densities and exact range due to the highly cryptic nature of the night snake.
(most active at dawn and dusk), and nocturnal. Night snakes are usually seen at night while crossing roads, but can be found under rocks, boards, dead branches and other surface litter during the day. Although the night snake poses no threat to humans, it is slightly venomous and uses this venom to subdue its prey. Their main prey is lizards, a study in southwestern Idaho found that the night snakes diet consisted mostly of side-blotched lizard
s (Uta stansburiana) and their eggs. Other prey includes juvenile rattlesnake
s and blind snakes, salamanders, frogs, and large insects.
Night snakes hibernate during the winter months and are known to aestivate during periods of the summer. They are generally most active from April to October, with peaks of activity usually occurring in June. Night snakes are known to be docile and easily handled. If threatened, the night snake may coil up and thrust its coils at the threat while flattening its head into a triangular defensive shape. Female night snakes are usually longer and larger than males.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of rear-fanged, colubrid
Colubrid
A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...
snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
known as the night snake. They are found through the south and western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, as well as Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The number of subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
varies depending on the source, but it is generally accepted that there are 17.
Subspecies
- Boulenger's Night Snake Hypsiglena torquata affinis BoulengerGeorge Albert BoulengerGeorge Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:...
, 1894 - Cedros IslandCedros IslandCedros Island is a Mexican island in the Pacific Ocean....
Night Snake, Hypsiglena torquata baueri (Zweifel, 1958) - Santa CatalinaSanta CatalinaSanta Catalina may refer to:*Argentina**Santa Catalina, Jujuy**Santa Catalina, Córdoba**Santa Catalina, Santiago del Estero*Colombia**Santa Catalina, Colombia**Archipelago of San Andres, Providencia and Santa Catalina*Dominican Republic...
Night Snake, Hypsiglena torquata catalinae (Tanner, 1966) - SonoraSonoraSonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
n Night Snake, Hypsiglena torquata chlorophaea (CopeEdward Drinker CopeEdward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
, 1860) - Desert Night Snake, Hypsiglena torquata deserticola (Tanner, 1966)
- Isla PartidaIsla PartidaIsla Partida is connected to Isla Espíritu Santo by a narrow isthmus. 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 California Peninsula in Mexico...
Night Snake, Hypsiglena torquata gularis (Tanner, 1954) - Texas Night Snake, Hypsiglena torquata janiHypsiglena torquata janiThe Texas night snake is a species of small colubrid snake native to the southern United States and Mexico. The epithet jani is in honor of Italian taxonomist Giorgio Jan.- Description :...
(DugèsAlfredo DugèsAlfredo Dugès ; was a French-born, Mexican physician and naturalist who was born in Montpellier. He was the son of zoologist Antoine Louis Dugès...
, 1866) - San Diego Night Snake, Hypsiglena torquata klauberi (Tanner, 1944)
- Mesa Verde Night Snake, Hypsiglena torquata loreala (Tanner, 1944)
- San Martin Island Night Snake, Hypsiglena torquata martinensis (Tanner & Banta 1962)
- California Night SnakeCalifornia Night SnakeThe California Night Snake is a species of small colubrid snake native to California.- Description :The California Night Snake grows from 12 to 26 inches in length, with hatchlings about 7 inches.The snake has a narrow flat head, smooth scales in 19 rows, and eyes with vertically...
, Hypsiglena torquata nuchalata (Tanner, 1943) - Spotted Night Snake, Hypsiglena torquata ochrorhyncha (CopeEdward Drinker CopeEdward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
, 1860) - Tiburon IslandTiburón IslandTiburón Island is both the largest island in the Gulf of California and the largest island in Mexico, with an area of . It was made a nature reserve in 1963 by President Adolfo López Mateos. Tiburón is Spanish for shark. The etymology of the Seri name is unknown...
Night Snake, Hypsiglena torquata tiburonensis (Tanner, 1981) - Collared Night Snake Hypsiglena torquata torquata (GüntherAlbert C. L. G. GüntherAlbert Karl Ludwig Gotthilf Günther FRS, also Albert Charles Lewis Gotthilf Günther , was a German-born British zoologist, ichthyologist, and herpetologist....
, 1860) - Isla TortugaIsla TortugaIsla Tortuga is an island in the Gulf of California, created relatively recently in geologic terms by the volcanism associated with the East Pacific Rise. It lies east-northeast of the city of Santa Rosalía, in Mulegé Municipality. It has a surface area of 11.374 km² .-References:*...
Night Snake Hypsiglena torquata tortugensis (Tanner, 1944) - Clarion IslandClarion IslandIsla Clarión, formerly called Santa Rosa, is the second largest, westernmost and most remote of the Revillagigedo Islands, west of Socorro Island and over from the Mexican mainland and an area ². It has three prominent peaks. The westernmost and tallest peak, Monte Gallegos, is high...
Night Snake Hypsiglena torquata unaocularis (Tanner, 1944) - Central BajaBaja California PeninsulaThe Baja California peninsula , is a peninsula in northwestern Mexico. Its land mass separates the Pacific Ocean from the Gulf of California. The Peninsula extends from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south.The total area of the Baja California...
Night Snake, Hypsiglena torquata venusta (Mocquard, 1899)
Identification
Length is 12–26 in (30–66 cm). Pale grey, light brown, or beige in color with dark grey or brown blotches on the back and sides. The nightsnake's head is rather flat and triangular shaped and usually has a pair of dark brown blotches on the neck. It is often mistaken as a juvenile rattlesnakeRattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
, however the nightsnake's lack of rattles is an easy way to differentiate. Rattlesnakes are, however, born without a rattle. The nightsnake also has a black or dark brown bar behind the eyes that contrast against the white or pale grey upper labial scales. The belly of the nightsnake is white or yellowish and it also has a vertical pupil.
Distribution
The nightsnake has been found as far north as southern British ColumbiaBritish Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, and as far south as Guerrero, Mexico. The Eastern range of the night snake extends to Texas. Still, not much is known as far as population densities and exact range due to the highly cryptic nature of the night snake.
Habitat
The nightsnake is found in many differing types of habitat including: grasslands, deserts, sagebrush flats, chapparral, woodlands, thornscrub, thorn forest, and mountain meadows. Both rocky and sandy areas are inhabited by night snakes and elevations over 8,500 ft have been recorded. The night snake is also known to inhabit mammal burrows.Behavior
Night snakes are known to be both crepuscularCrepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
(most active at dawn and dusk), and nocturnal. Night snakes are usually seen at night while crossing roads, but can be found under rocks, boards, dead branches and other surface litter during the day. Although the night snake poses no threat to humans, it is slightly venomous and uses this venom to subdue its prey. Their main prey is lizards, a study in southwestern Idaho found that the night snakes diet consisted mostly of side-blotched lizard
Side-blotched lizard
Side-blotched lizards are lizards of the genus Uta. They are some of the most abundant and commonly observed lizards in the deserts of western North America. They commonly grow to six inches including the tail, with the males normally being the larger sex. Males often have bright throat colors....
s (Uta stansburiana) and their eggs. Other prey includes juvenile rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s and blind snakes, salamanders, frogs, and large insects.
Night snakes hibernate during the winter months and are known to aestivate during periods of the summer. They are generally most active from April to October, with peaks of activity usually occurring in June. Night snakes are known to be docile and easily handled. If threatened, the night snake may coil up and thrust its coils at the threat while flattening its head into a triangular defensive shape. Female night snakes are usually longer and larger than males.