Garter snake

Template:Short description {{#invoke:Hatnote|hatnote}} Template:Automatic taxobox

Garter snake is the common name for small to medium-sized snakes belonging to the genus Thamnophis in the family Colubridae. They are native to North and Central America, ranging from central Canada in the north to Costa Rica in the south.

With about 35 recognized species and subspecies, garter snakes are highly variable in appearance; generally, they have large round eyes with rounded pupils, a slender build, keeled scales (appearing ‘raised’), and a pattern of longitudinal stripes that may or may not include spots (although some have no stripes at all). Certain subspecies have stripes of blue, yellow, or red, mixed with black tops and beige-tan underbelly markings. They also vary significantly in total length, from Template:Cvt.

With no real consensus on the classification of the species of Thamnophis, disagreements between taxonomists and disputed sources (such as field guides) are common. One area of debate, for example, is whether or not two specific types of snake are separate species, or subspecies of the same. Garter snakes are closely related to the genus Nerodia (water snakes), with some species having been moved back and forth between genera.

As garter snakes may retain toxins from their amphibian prey in their liver, they are one of the few species of snakes in the world that can be both venomous and poisonous.

TaxonomyEdit

The first garter snake to be scientifically described was the eastern garter snake (now Thamnophis sirtalis sirtalis), by zoologist and taxonomist Carl Linnaeus in 1758. The genus Thamnophis was described by Leopold Fitzinger in 1843 as the genus for the garter snakes and ribbon snakes.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Many snakes previously identified as their own genera or species have been reclassified as species or subspecies in Thamnophis. The Reptile Database currently recognised 37 species in the genus, some with several subspecies.<ref>Template:Cite taxon</ref>

Distribution and habitatEdit

Native to North and Central America, species in the genus Thamnophis can be found in all of the lower 48 United States, and all of the Canadian provinces. They are found from the subarctic plains of west-central Canada east through Ontario and Quebec; from Atlantic Canada and south to Florida, across the southern and central U.S. into the arid regions of the southwest and Mexico, Guatemala and south to the neotropics and Costa Rica.

Garter snakes are not originally native to the eastern Canadian island of Newfoundland, but have been breeding there in the wild and gradually spreading since at least 2010. It is unknown how they reached the island, probably accidentally via hay shipments or as escaped pets.<ref>CBC News, "Think there aren't any snakes in Newfoundland? Think again", June 25, 2024. Accessed on June 27, 2024.</ref><ref>Nature Conservancy Canada, "Snakes, saints and sightings: What you can do to help uncover the mystery of gartersnakes in Newfoundland". Accessed on June 27, 2024.</ref>

Their wide distribution is due to their varied diets and adaptability to different habitats, with varying proximity to water. However, in the western part of North America these snakes are more aquatic than in the eastern portion. Garter snakes live in a variety of habitats, including forests, woodlands, fields, grasslands and lawns, but never far from water, often an adjacent wetland, stream or pond. This reflects the fact that amphibians are a large part of their diet. Garter snakes are often found near small ponds with tall weeds.

BehaviorEdit

File:Garter snake tooth.jpg

The posterior tooth of a garter snake

Garter snakes have complex pheromonal communication systems. They can find other snakes by following their pheromone-scented trails. Male and female skin pheromones are so different as to be immediately distinguishable. However, male garter snakes sometimes produce both male and female pheromones. During the mating season, this ability fools other males into attempting to mate with them. This causes the transfer of heat to them in kleptothermy, which is an advantage immediately after hibernation, allowing them to become more active.<ref>Template:Cite journal</ref> Male snakes giving off both male and female pheromones have been shown to garner more copulations than normal males in the mating balls that form at the den when females enter the mating melee. A snake hatch can include as many as 57 young.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Garter snakes use the vomeronasal organ to communicate via pheromones through tongue flicking, which gathers chemical cues in the environment. Upon entering the lumen of the organ, the chemical molecules will come into contact with the sensory cells, which are attached to the neurosensory epithelium of the vomeronasal organ.Template:Citation needed

If disturbed, a garter snake may coil and strike, but it typically hides its head and flails its tail. These snakes will also discharge a malodorous, musky-scented secretion from a gland near the cloaca. This secretion from North American garter snakes contains seven highly odoriferous volatile components: acetic, propanoic, 2-methylpropanoic, butanoic, and 3-methylbutanoic acids; and trimethylamine, and 2-piperidone.<ref>Template:Cite journal</ref> They often use these techniques to escape when ensnared by a predator. They will also slither into the water to escape a predator on land. Hawks, crows, egrets, herons, cranes, raccoons, otters and other snake species (such as coral snakes and kingsnakes) will eat garter snakes, with even shrews and frogs eating the juveniles.

File:Garter Snake Scales.tif

Close up of the scales on the back of the common garter snake

Being heterothermic, like all reptiles, garter snakes bask in the sun to regulate their body temperature. During brumation (the reptile equivalent of hibernation), garter snakes typically occupy large communal sites called hibernacula. These snakes will migrate large distances to brumate.

Social behaviorEdit

A long-term study by the Ontario Ministry of Transportation has shed light on the social behavior of Butler's garter snakes. The study, conducted in a 250-hectare area near Windsor, Canada, tracked over 3,000 individual snakes over a 12-year period. The findings challenge previous assumptions about solitary snake behavior and suggest that these snakes form social groups and communities. The study revealed that Butler's garter snakes do not wander randomly but instead tend to associate with specific groups of snakes. These groups typically consist of three to four individuals, with some larger groups reaching up to 46 snakes.<ref>Template:Cite news</ref><ref>Template:Cite journal</ref>

DietEdit

File:Garter swallowing frog.jpg

Eating a frog

Garter snakes, like all snakes, are carnivorous. Their diet consists of almost any creature they are capable of overpowering: slugs, earthworms (nightcrawlers, as redworms are toxic to garter snakes), leeches, lizards, amphibians (including frog eggs), minnows, and rodents. When living near water, they eat other aquatic animals. The ribbon snake (Thamnophis saurita) in particular favors frogs (including tadpoles), readily eating them despite their strong chemical defenses. Food is swallowed whole. Garter snakes often adapt to eating whatever they can find and whenever they can find it because food can be either scarce or abundant. Although they feed mostly on live animals they will sometimes eat eggs.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

VenomEdit

Garter snakes were long thought to be non-venomous, but discoveries in the early 2000s revealed that they produce a neurotoxic venom.<ref>Template:Cite news</ref> Despite this, garter snakes cannot seriously injure or kill humans with the small amounts of comparatively mild venom they produce and they also lack an effective means of delivering it. In a few cases, some swelling and bruising has been reported.<ref name=warm/> They do have enlarged teeth in the back of their mouths<ref>Template:Cite journal</ref> but their gums are significantly larger and the secretions of their Duvernoy's gland are only mildly toxic.<ref name=warm>Template:Cite magazine</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Evidence suggests that garter snake and newt populations share an evolutionary link in their tetrodotoxin resistance levels, implying co-evolution between predator and prey.<ref>Template:Cite journal</ref> Garter snakes feeding on toxic newts can also retain those toxins in their liver for weeks, making those snakes poisonous as well as venomous.<ref>Template:Cite journal</ref>

Conservation statusEdit

File:Mating ball of garter snakes.jpg

A mating ball

File:Gartersnake2128.JPG

A young garter snake

Despite the decline in their population from collection as pets (especially in the more northerly regions, in which large groups are collected at hibernation),<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> pollution of aquatic areas, and the introduction of American bullfrogs as potential predators, garter snakes are still some of the most commonly found reptiles in much of their ranges. The San Francisco garter snake (Thamnophis sirtalis tetrataenia), however, has been on the endangered list since 1969. Predation by crayfish has also been responsible for the decline of the narrow-headed garter snake (Thamnophis rufipunctatus).<ref name=IUCN>Template:Cite iucn</ref> Many breeders have bred all species of garter snakes, making it a popular breed.

Species and subspeciesEdit

Arranged alphabetically by scientific name:

Image	Name	Subspecies	Distribution
	Thamnophis ahumadai Template:Small<ref>Template:Cite journal</ref>		Jalisco Mountain, Mexico
File:Thamnophis atratus (1).jpg	Aquatic garter snake, Thamnophis atratus Template:Small	Santa Cruz garter snake, T. a. atratus Template:Small Oregon garter snake, T. a. hydrophilus Template:Small Diablo Range garter snake, T. a. zaxanthus Template:Small	coast of Oregon and California.
	Bogert's garter snake, Thamnophis bogerti Template:Small		Oaxaca, Mexico
	Shorthead garter snake, Thamnophis brachystoma Template:Small		northwestern Pennsylvania and southwestern New York.
File:Thamnophis butleri.jpg	Butler's garter snake, Thamnophis butleri Template:Small		northwestern Ohio, northeastern Indiana, the eastern portion of the Lower Peninsula of Michigan, and the adjacent extreme southern tip of Ontario, Canada.
	Goldenhead garter snake, Thamnophis chrysocephalus Template:Small		Mexico.
	Conant's garter snake, Thamnophis conanti Template:Small		Puebla and Veracruz, Mexico.
	Cope's mountain meadow snake, Thamnophis copei Template:Small		Mexico.
File:Sierra garter snake handled.jpg	Sierra garter snake, Thamnophis couchii Template:Small		California and Oregon in the United States
File:Thamnophis cyrtopsis ocellatus.jpg	Blackneck garter snake, Thamnophis cyrtopsis Template:Small	Western blackneck garter snake, T. c. cyrtopsis Template:Small Eastern blackneck garter snake, T. c. ocellatus Template:Small Tropical blackneck garter snake, T. c. collaris Template:Small	southwestern United States, Mexico and Guatemala
File:Coast Garter Snake.jpg	Western terrestrial garter snake, Thamnophis elegans Template:Small	Arizona garter snake, T. e. arizonae Template:Small Mountain garter snake, T. e. elegans Template:Small San Pedro Mártir garter snake, T. e. hueyi Template:Small Coastal garter snake, T. e. terrestris Template:Small Wandering garter snake, T. e. vagrans Template:Small Upper Basin garter snake, T. e. vascotanneri Template:Small	central British Columbia, central Alberta, and southwestern Manitoba in Canada, central United States
File:Thamnophis eques1.jpg	Mexican garter snake, Thamnophis eques Template:Small	Mexican garter snake, T. e. eques Template:Small Laguna Totolcingo garter snake, T. e. carmenensis Template:Small T. e. cuitzeoensis Template:Small T. e. diluvialis Template:Small T. e. insperatus Template:Small Northern Mexican garter snake, T. e. megalops Template:Small T. e. obscurus Template:Small T. e. patzcuaroensis Template:Small T. e. scotti Template:Small T. e. virgatenuis Template:Small	Mexico and in the United States (Arizona and New Mexico).
File:Thamnophis errans.jpg	Mexican wandering garter snake, Thamnophis errans Template:Small		Chihuahua, Durango, Jalisco, Nayarit, and Zacatecas States of Mexico.
	Montane garter snake, Thamnophis exsul Template:Small		Mexico.
	Fox's mountain meadow snake, Thamnophis foxi Template:Small		Mexico.
	Highland garter snake, Thamnophis fulvus Template:Small		Mexico, Guatemala, Honduras and El Salvador.
File:Giant Garter Snake 1.jpg	Giant garter snake, Thamnophis gigas Template:Small		central California.
	Godman's garter snake,<ref>Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. Template:ISBN. (Thamnophis godmani, p. 102).</ref> Thamnophis godmani Template:Small		southern Mexico
File:Thamnophis hammondii 02.jpg	Two-striped garter snake, Thamnophis hammondii Template:Small		central California to Baja California, Mexico
	Liner's garter snake, Thamnophis lineri<ref>Thamnophis lineri. The Reptile Database. http://www.reptile-database.org.</ref> Template:Small		Mexico.
File:Thamnophis marcianus.jpg	Checkered garter snake, Thamnophis marcianus Template:Small	T. m. marcianus Template:Small T. m. praeocularis Template:Small T. m. bovalli Template:Small	southwestern United States, Mexico, and Central America.
File:Blackbelly Garter Snake imported from iNaturalist photo 162669277 on 15 November 2021.jpg	Blackbelly garter snake, Thamnophis melanogaster Template:Small	Gray blackbelly garter snake, T. m. canescens Template:Small Chihuahuan blackbelly garter snake, T. m. chihuahuanensis Template:Small Lined blackbelly garter snake, T. m. linearis Template:Small Mexican blackbelly garter snake, T. m. melanogaster Template:Small	Mexico.
	Tamaulipan montane garter snake, Thamnophis mendax Template:Small		Mexico.
	Southern Durango spotted garter snake, Thamnophis nigronuchalis Template:Small		Durango, Mexico.
File:Thamnophis ordinoides 071616 A.jpg	Northwestern garter snake, Thamnophis ordinoides Template:Small		California, Oregon, and Washington; in Canada, it is found in British Columbia
	Tepalcatepec Valley garter snake, Thamnophis postremus Template:Small		Mexico.
File:Thamnophis proximus rubrilineatus.jpg	Western ribbon snake, Thamnophis proximus Template:Small	Chiapas Highlands ribbon snake, T. p. alpinus Template:Small Arid land ribbon snake, T. p. diabolicus Template:Small Gulf Coast ribbon snake, T. p. orarius Template:Small Orangestripe ribbon snake or western ribbon snake T. p. proximus Template:Small Redstripe ribbon snake, T. p. rubrilineatus Template:Small Mexican ribbon snake, T. p. rutiloris Template:Small	western United States, Mexico, and Central America
File:Thamnophis pulchrilatus4.jpg	Yellow-throated garter snake, Thamnophis pulchrilatus Template:Small		Mexico.
File:Thamnophis-radix.JPG	Plains garter snake, Thamnophis radix Template:Small		central United States as far north as Canada and as far south as Texas.
	Rossman's garter snake, Thamnophis rossmani Template:Small		Mexico.
	Narrow-headed garter snake, Thamnophis rufipunctatus Template:Small		Arizona and New Mexico, and in the Mexican states of Sonora, Chihuahua and Durango
File:EasternRibbonSnake.jpg	Ribbon snake, Thamnophis saurita Template:Small	Bluestripe ribbon snake, T. s. nitae Template:Small Southern ribbon snake, T. s. sackenii Template:Small Eastern ribbon snake, T. s. saurita Template:Small Northern ribbon snake, T. s. septentrionalis Template:Small	Eastern North America
File:Thamnophis scalaris.jpg	Longtail alpine garter snake, Thamnophis scalaris Template:Small		Mexico.
	Short-tail alpine garter snake, Thamnophis scaliger Template:Small		Mexico.
File:Thamnophis sirtalis annectens.jpg	Common garter snake, Thamnophis sirtalis Template:Small	Texas garter snake, T. s. annectens Template:Small Red-spotted garter snake, T. s. concinnus Template:Small New Mexico garter snake, T. s. dorsalis Template:Small valley garter snake, T. s. fitchi Template:Small California red-sided garter snake, T. s. infernalis Template:Small T. s. lowei Template:Small Maritime garter snake, T. s. pallidulus Template:Small Red-sided garter snake, T. s. parietalis Template:Small Puget Sound garter snake, T. s. pickeringii Template:Small Blue-striped garter snake, T. s. similis Template:Small Eastern garter snake, T. s. sirtalis Template:Small Chicago garter snake, T. s. semifasciatus Template:Small San Francisco garter snake, T. s. tetrataenia Template:Small	North America
	Sumichrast's garter snake, Thamnophis sumichrasti Template:Small		Mexico.
	Madrean narrow-headed garter snake, Thamnophis unilabialis Template:Small		Mexico.
	West Coast garter snake, Thamnophis validus Template:Small	Mexican Pacific Lowlands garter snake, T. v. celaeno Template:Small T. v. isabellae Template:Small T. v. thamnophisoides Template:Small T. v. validus Template:Small	Mexico.

In the above list, a binomial authority or a trinomial authority in parentheses indicates that the species or subspecies was originally described in a genus other than Thamnophis.