The article is about North American garter snakes.
For the unrelated venomous snakes of Africa also called garter snakes, see Elapsoidea.
|Scientific classification Thamnophis|
Garter snakes vary in length from 46 to 137 cm (18 to 54 in), and weigh approximately 140 g (5 oz).
With no real consensus on the classification of species of Thamnophis, disagreement between taxonomists and sources such as field guides over whether two types of snakes are separate species or subspecies of the same species is common.
Garter snakes are closely related to the genus Nerodia (water snakes), with some species having been moved back and forth between genera.
The genus Thamnophis was described by Leopold Fitzinger in 1843 as the genus for the garter snakes and ribbon snakes.
Many snakes previously identified as their own genera or species have been reclassified as species or subspecies in Thamnophis.
There are currently 35 species within the genus, with several subspecies within some of them.
Garter snakes are present throughout most of North America.
They have a wide distribution 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 populate a variety of habitats, including forests, woodlands, fields, grasslands, and lawns, but never far away from some form of water, often an adjacent wetland, stream, or pond.
This reflects the fact that amphibians are a large part of their diet.
Garter snakes have complex systems of pheromonal communication.
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.
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.
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.
If disturbed, a garter snake may coil and strike, but typically it will hide its head and flail its tail.
These snakes will also discharge a malodorous, musky-scented secretion from a gland near the cloaca.
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.
During brumation (the reptile equivalent of hibernation), garter snakes typically occupy large, communal sites called hibernacula.
These snakes will migrate large distances to brumate.
Garter snakes, like all snakes, are carnivorous.
Their diet consists of almost any creature they are capable of overpowering: slugs, earthworms (nightcrawlers, as red wigglers are toxic to garter snakes), leeches, lizards, amphibians (including frog eggs), minnows, and rodents.
When living near water, they will eat other aquatic animals.
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.
Garter snakes were long thought to be nonvenomous, but discoveries in the early 2000s revealed that they in fact produce a neurotoxic venom.
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 very rare cases, some swelling and bruising have been reported.
They do have enlarged teeth in the back of their mouths, but their gums are significantly larger, and the secretions of their Duvernoy's gland are only mildly toxic.
Evidence suggests that garter snake and newt populations share an evolutionary link in their levels of tetrodotoxin (TTX) resistance, implying co-evolution between predator and prey.
Garter snakes feeding upon toxic newts can also retain those toxins in their liver for weeks, making those snakes poisonous as well as venomous.
Despite the decline in their population from collection as pets (especially in the more northerly regions in which large groups are collected at hibernation), 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, is an endangered subspecies and has been on the endangered list since 1969.
Species and subspecies
Arranged alphabetically by scientific name:
- Aquatic garter snake, T. atratus (Kennicott, 1860)
- Santa Cruz garter snake, T. a. atratus (Kennicott, 1860)
- Oregon garter snake, T. a. hydrophilus Fitch, 1936
- Diablo Range garter snake, T. a. zaxanthus Boundy, 1999
- Bogert's garter snake, T. bogerti Rossman & Burbrink, 2005
- Shorthead garter snake, T. brachystoma (Cope, 1892)
- Butler's garter snake, T. butleri (Cope, 1889)
- Goldenhead garter snake, T. chrysocephalus (Cope, 1885)
- Conant's garter snake, T. conanti Rossman & Burbrink, 2005
- Sierra garter snake, T. couchii (Kennicott, 1859)
- Blackneck garter snake, T. cyrtopsis (Kennicott, 1860)
- Western blackneck garter snake, T. c. cyrtopsis (Kennicott, 1860)
- Eastern blackneck garter snake, T. c. ocellatus (Cope, 1880)
- Tropical blackneck garter snake, T. c. collaris (Jan, 1863)
- Western terrestrial garter snake, T. elegans (Baird & Girard, 1853)
- Arizona garter snake, T. e. arizonae W. Tanner & Lowe, 1989
- Mountain garter snake, T. e. elegans (Baird & Girard, 1853)
- San Pedro Mártir garter snake, T. e. hueyi Van Denburgh & Slevin, 1923
- Coastal garter snake, T. e. terrestris Fox, 1951
- Wandering garter snake, T. e. vagrans (Baird & Girard, 1853)
- Upper Basin garter snake, T. e. vascotanneri W. Tanner & Lowe, 1989
- Mexican garter snake, T. eques (, 1834)
- Mexican garter snake, T. e. eques (Reuss, 1834)
- Laguna Totolcingo garter snake, T. e. carmenensis Conant, 2003
- T. e. cuitzeoensis Conant, 2003
- T. e. diluvialis Conant, 2003
- T. e. insperatus Conant, 2003
- Northern Mexican garter snake, T. e. megalops (Kennicott, 1860)
- T. e. obscurus Conant, 2003
- T. e. patzcuaroensis Conant, 2003
- T. e. scotti Conant, 2003
- T. e. virgatenuis Conant, 1963
- Mexican wandering garter snake, T. errans H. M. Smith, 1942
- Montane garter snake, T. exsul Rossman, 1969
- Highland garter snake, T. fulvus (Bocourt, 1893)
- Giant garter snake, T. gigas Fitch, 1940
- Godman's garter snake, T. godmani (Günther, 1894)
- Two-striped garter snake, T. hammondii (Kennicott, 1860)
- Liner's garter snake, T. lineri Rossman & Burbrink, 2005
- Checkered garter snake, T. marcianus (Baird & Girard, 1853)
- T. m. marcianus (Baird & Girard, 1853)
- T. m. praeocularis (Bocourt, 1892)
- T. m. bovalli (Dunn, 1940)
- Blackbelly garter snake, T. melanogaster
- Tamaulipan montane garter snake, T. mendax Walker, 1955
- Southern Durango spotted garter snake, T. nigronuchalis Thompson, 1957
- Northwestern garter snake, T. ordinoides (Baird & Girard, 1852)
- Tepalcatepec Valley garter snake, T. postremus Smith, 1942
- Western ribbon snake, T. proximus (Say, 1823)
- Chiapas Highlands ribbon snake, T. p. alpinus Rossman, 1963
- Arid land ribbon snake, T. p. diabolicus Rossman, 1963
- Gulf Coast ribbon snake, T. p. orarius Rossman, 1963
- Orangestripe ribbon snake or western ribbon snake T. p. proximus (Say, 1823)
- Redstripe ribbon snake, T. p. rubrilineatus Rossman, 1963
- Mexican ribbon snake, T. p. rutiloris (Cope, 1885)
- Yellow-throated garter snake, T. pulchrilatus (Cope, 1885)
- Plains garter snake, T. radix (Baird & Girard, 1853)
- Rossman's garter snake, T. rossmani Conant, 2000
- Narrow-headed garter snake, T. rufipunctatus (Cope, 1875)
- Ribbon snake, T. sauritus (Linnaeus, 1766)
- Bluestripe ribbon snake, T. s. nitae Rossman, 1963
- Southern ribbon snake, T. s. sackenii (Kennicott, 1859)
- Eastern ribbon snake, T. s. sauritus (Linnaeus, 1766)
- Northern ribbon snake, T. s. septentrionalis Rossman, 1963
- Longtail alpine garter snake, T. scalaris (Cope, 1861)
- Short-tail alpine garter snake, T. scaliger (Jan, 1863)
- Common garter snake, T. sirtalis
- Texas garter snake, T. s. annectens Brown, 1950
- Red-spotted garter snake, T. s. concinnus (Hallowell, 1852)
- New Mexico garter snake, T. s. dorsalis (Baird & Girard, 1853)
- valley garter snake, T. s. fitchi Fox, 1951
- California red-sided garter snake, T. s. infernalis (Blainville, 1835)
- T. s. lowei W. Tanner, 1988
- Maritime garter snake, T. s. pallidulus Allen, 1899
- Red-sided garter snake, T. s. parietalis (Say, 1823)
- Puget Sound garter snake, T. s. pickeringii (Baird & Girard, 1853)
- Blue-striped garter snake, T. s. similis Rossman, 1965
- Eastern garter snake, T. s. sirtalis (Linnaeus, 1758)
- Chicago garter snake, T. s. semifasciatus (Cope, 1892)
- San Francisco garter snake, T. s. tetrataenia (Cope, 1875)
- Sumichrast's garter snake, T. sumichrasti (Cope, 1866)
- Madrean narrow-headed garter snake, T. unilabialis W. Tanner, 1985
- West Coast garter snake, T. validus
- Mexican Pacific Lowlands garter snake, T. v. celaeno (Cope, 1860)
- T. v. isabellae (Conant, 1953)
- T. v. thamnophisoides (Conant, 1961)
- T. v. validus (Kennicott, 1860)
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Garter snake.