Hypsiglena
Encyclopedia
Hypsiglena is a genus
of small, rear-fanged, colubrid
snake
s commonly referred to as night snakes. The genus consists of two distinct species
, many subspecies
may be considered synonymous depending on the source.
from Texas
and Kansas
, west to California
, north to Washington, and south into Mexico
, as well as islands off the coasts of Mexico. Their preferred habitat is semi-arid desert
regions with rocky and sandy soil
s.
s with vertical pupil
s. Their color varies depending on their locality, often matching the soil color of their native habitat. They are 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.
. Their diet consists primarily of lizard
s, but they will also consume smaller snake
s, and amphibian
s. Their venom is not considered to be dangerous to humans.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of small, 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...
s commonly referred to as night snakes. The genus consists of two distinct species
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...
, many 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...
may be considered synonymous depending on the source.
Species
- Tanzer's Day Snake, Hypsiglena tanzeri (DixonJames R. DixonDr. James Ray Dixon is Professor Emeritus and Curator Emeritus of Amphibians and Reptiles at the Texas Cooperative Wildlife Collection at Texas A&M University. His main research focus has been the natural history of Texas amphibians and reptiles and he has authored numerous field guides and...
& Lieb, 1972) - Hypsiglena torquataHypsiglena torquataHypsiglena 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...
- 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...
, 1865) - 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)
- Boulenger's Night Snake Hypsiglena torquata affinis (Boulenger
Geographic range
Hypsiglena are found throughout the north and eastern United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
from Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
, west to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, north to Washington, and south into 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...
, as well as islands off the coasts of Mexico. Their preferred habitat is semi-arid desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
regions with rocky and sandy soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s.
Description
Night snakes typically do not get much larger than 40 cm. They are slender bodied with a flattened head, and have small eyeEye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
s with vertical pupil
Pupil
The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...
s. Their color varies depending on their locality, often matching the soil color of their native habitat. They are occur in various shades of gray, and brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
, with dark brown, gray or black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
blotches on the back and the sides. Many also have distinctive black markings on the neck region.
Behavior
Hypsiglena are a nocturnal and terrestrialTerrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
. Their diet consists primarily of lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s, but they will also consume smaller 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...
s, and amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s. Their venom is not considered to be dangerous to humans.