The plains garter snake (''Thamnophis radix'') is a species of

garter snake Garter snake is a common name for generally harmless, small to medium-sized snakes belonging to the genus ''Thamnophis'' in the family Colubridae. Native to North and Central America, species in the genus ''Thamnophis'' can be found from the ...

native to most of the central United States as far north as Canada and as far south as

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

. It has a distinctive orange or yellow stripe from its head to tail, and the rest of its body is mainly a gray-green color. The snake is commonly found living near water sources such as streams and ponds, but can also be found in urban areas and vacant lots. Although the IUCN lists the species as "Least Concern", some states have given it their own special status. This species is mildly venomous, although the venom is not toxic to humans.

Description

Physical

The plains garter snake has either an orange or yellow stripe down its back and distinctive black bars on its lip. The stripe normally starts at the head and continues all the way to the tail tip.

Lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction * Lateral cricoarytenoid muscle * Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...

stripes are located on the third and fourth scale rows and are normally a greenish-yellow color. Its belly is gray-green with small dark spots along the edges. Most have distinctive light yellow spots on the top of the head. The snake is described as medium-sized and is on average around .

Behavior

Described as "one of the most cold-tolerant snakes", on warmer winter days, it often comes out of hibernation to bask in the sun. It is most active between April and late October depending on location. Mating normally takes place in April or May and birth takes place between August and October. Courtship usually occurs near the communal hibernation site, and polygynous

mating system A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mate under which circumstances. Recognised ...

s have been observed. The snake's typical diet consists of

earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. T ...

s, slugs, and small amphibians, including the larvae of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s. It has also been observed eating small mammals and birds, such as

bank swallow The sand martin (''Riparia riparia''), also known as the bank swallow (in the Americas), collared sand martin, or common sand martin, is a migratory passerine bird in the swallow family. It has a wide range in summer, embracing practically the ...

s and

eastern meadowlark The eastern meadowlark (''Sturnella magna'') is a medium-sized blackbird (family: Icteridae), very similar in appearance to sister species western meadowlark. It occurs from eastern North America to northern South America, where it is also most w ...

Habitat

The plains garter snake is commonly found in

meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or arti ...

s and

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

s adjacent to water sources, such as

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es, streams, and

pond A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from ...

s. In built-up areas of the

Chicago area The Chicago metropolitan area, also colloquially referred to as Chicagoland, is a metropolitan area in the Midwestern United States. Encompassing 10,286 sq mi (28,120 km2), the metropolitan area includes the city of Chicago, its suburbs and hi ...

, it has been observed in abandoned buildings, trash heaps, and vacant lots. Populations in urban and suburban areas have been greatly reduced due to building activities and pesticide use. Its habitat range overlaps with that of the

common garter snake The common garter snake (''Thamnophis sirtalis'') is a species of thamnophis snake, in the natricine subfamily, which is indigenous to North America and found widely across the continent. Most common garter snakes have a pattern of yellow strip ...

(''Thamnophis sirtalis'') in many areas, and it is thought the two species may hybridize.

Range

The snake ranges across a broad area of North America from as far north as central

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

to as far south as

Northern Texas North Texas (also commonly called North Central Texas) is a term used primarily by residents of Dallas, Fort Worth, and surrounding areas to describe much of the north central portion of the U.S. state of Texas. Residents of the Dallas–Fort Wor ...

and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

. In the United States, it is also found in

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to th ...

, eastern

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

, northern

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...

, eastern

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

, southern

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...

, northwestern

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

, Oklahoma, Nebraska and the northern half of Missouri. A small population is also in Ohio. In Canada, the species is also found in

Manitoba , image_map = Manitoba in Canada 2.svg , map_alt = Map showing Manitoba's location in the centre of Southern Canada , Label_map = yes , coordinates = , capital = Winn ...

. It can be found at elevations from 400 to 7,500 feet, but prefers to stay under 6,000 feet.

Subspecies

Formerly, two subspecies of the plains garter snake were widely recognized, but most authorities have since dropped recognition of them. The first, ''T. r. radix'', was commonly referred to as the eastern plains garter snake, while ''T. r. haydeni'' ( Kennicott, 1860) was commonly referred to as the western plains garter snake. However, the distinction between the two of them is weak, partly based on the number of scales and partly on slight coloration differences, with ''T. r. haydeni'' said to have cleaner markings and more ventral and neck scales. As the two subspecies share the same habitat in many regions of the United States, further complicated by their strikingly similar appearance, many authorities now do not recognize them. The subspecific name ''haydeni'' was in honor of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althoug ...

Ferdinand Vandeveer Hayden Ferdinand Vandeveer Hayden (September 7, 1829 – December 22, 1887) was an American geologist noted for his pioneering surveying expeditions of the Rocky Mountains in the late 19th century. He was also a physician who served with the Union Ar ...

Conservation

The plains garter snake is listed as

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

(IUCN 3.1) by the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

due to the snake's ability to modify its habitat, its wide distribution and its presumed large population. However, the species is considered to be

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

in Ohio and it is on a state list of endangered species. In Wisconsin, it is a species of special concern.

References

External links

Plains Garter Snake
Reptiles and Amphibians of Iowa

Plains Garter Snake, Reptiles of Alberta: Alberta Conservation Association {{Authority control Thamnophis Snakes of North America Reptiles of Canada Reptiles of the United States Fauna of the Great Plains Fauna of the Plains-Midwest (United States) Fauna of the Southwestern United States Reptiles described in 1853 Taxa named by Spencer Fullerton Baird Taxa named by Charles Frédéric Girard Least concern biota of the United States Pliocene reptiles of North America Extant Zanclean first appearances