Garter Snakes, are small snakes that make up the genus ‘Thamnophis‘, in the subfamily Natricinae. Within the genus, there are around 37 species and over 50 subspecies. The most numerous is the common garter snake (Thamnophis sirtalis) which has 13 subspecies across their range. They can be found throughout Central America and North America, each species with its unique characteristics.
While they share the name ‘garter snake’ with the African garter snake (Elapsoidea), they’re very different and belong to separate families, on separate continents in the vast snake world.
With their size and often versatile nature, they are a common choice of pet for reptile enthusiasts, particularly first timers that want a relatively easy snake to care for.
Appearance & Characteristics of the Garter Snakes
Garter Snakes are medium-sized, typically ranging between 18 to 54 inches (46 – 130 cm) in length, but with an average adult length closer to 22 inches (55cm). In terms of weight, they average around 150 grams, but again this can vary widely depending on age and length. They have a slender, slick build and bodies that are usually adorned with stripes, which can vary in color and pattern depending on the species.
Some have bright, contrasting colors, while others have more muted tones to blend seamlessly with their environment. Their eyes are alert and curious, always on the lookout for potential prey or threats. While garter snakes do produce venom, they are not dangerous snakes. Their venom is mild and they don’t have big, scary looking fangs to deliver the toxins like other snakes such as the gaboon viper.
Distribution – Location and Habitat
From the chilly regions of British Colombia in Canada to the warmer areas of Guatemala and Mexico in Central America, Garter Snakes have made Central and North America their playground. They’re incredibly versatile and can thrive in various habitats. Wetlands, meadows, woodlands, and even urban gardens can be their home. As long as there’s food and a safe spot to sunbathe or hide, a Garter Snake is content.
They are not common in desert and arid areas though, tending to stick toward areas with good access to water. Species that live in the west of the Americas appear to be more aquatic than those living in the east, with the latter preferring more forested, prairie or meadowland.
Each species and subspecies has it’s own range, for example the San Francisco Garter Snake (T. s. tetrataenia) is found only in the specific county of San Matteo in California. The Eastern Garter Snake (T. s. sirtalis) on the other hand can be found widely across the east coast, from Ontario to Florida.
The Lifestyle & Behaviour of the Garter Snakes
Active during the day, Garter Snakes are diurnal animals. They love basking in the sun to regulate their body temperature. However, if the sun gets too intense, they’ll seek shade or burrow into the ground. They are known to be social animals from time to time too. During colder months in the northern areas of their range, they might huddle together in large groups, forming ‘snake balls’ to conserve heat. They often do this for other reasons during mating season too.
Like most reptiles, they are not particularly friendly in their nature, but they can learn to be non reactive or gentle to handling when looked after properly. They have great eyesight that helps them with hunting but also for predator avoidance.
They have various methods of communication, but the most interesting is through pheromone trails. Males and females can tell each other apart immediately by the sense of their pheromones. The scent, to these snakes is unmistakable, and they can track other snakes by following these pheromone trails.
They are more likely to flight rather than fight if approached by a predator, but not always, they are more than capable of striking if they must. In most cases though they will burry their heads, or take to the water.
Diet & Nutrition of the Garter Snakes
Garter snakes are carnivorous reptiles, and they are not particularly fussy about what they eat. Some of their favourite foods include earthworms, slugs, fish, leeches and amphibians are some of their favorites. They have a keen sense of smell, which they use to track down their prey. Some larger Garter Snakes might even go after rodents, small mammals or birds! As such, they are known to be a really good species for controlling common pests.
Predators & Threats to the Garter Snakes
Garter Snakes are not at the top of the food chain in their ecosystem, and have many threats to watch out for on land and from the air. Birds of prey such as hawks and cranes are common aerial threats. Raccoons, otters, larger snakes, and even some amphibians are common threats from the land or water. Their mild venom can deter some threats, but it’s not always enough. They also have a unique defence mechanism where they release a foul-smelling musk to ward off predators.
Garter Snakes Reproduction
Garter Snakes are ovoviviparous, meaning they give birth to live young instead of laying eggs. The females usually have the pick of the bunch from all the male contenders, as they are often greatly outnumbered. They will often form what’s known as a ‘mating ball’ when a few females are swarmed by a bundle of males all looking to reproduce.
After a mating dance, the female can store the male’s sperm and decide when to fertilize her eggs. If mating occurs before hibernation, she may choose to delay fertilization until the spring. Once she does, she can give birth to anywhere from 12 to 40 baby snakes on average, or up to 60 with some specific species.
Lifespan of the Garter Snakes
In the wild, Garter Snakes usually live for about 2 to 10 years, but some species live longer than others. The Common Garter Snake and all of it’s subspecies for example, live on average between 4 to 5 years in the wild, but can live for double that in captivity. Their first year is crucial as they grow rapidly. By their second year, they reach maturity and are ready to reproduce. As they age, they face more threats, but their experience often helps them navigate challenges.
Population and Conservation
The majority of garter snakes are listed as species of Least Concern by the IUCN, but the list doesn’t take into account particular subspecies. For example, the Common Garter Snake (Thamnophis sirtalis) is listed as Least concern, but the San Francisco Garter Snake which is a subspecies of the common variety, is actually Endangered, and has had this listing since the 1960’s. The IUCN doesn’t recognise the subspecies status.
Of all the other garter snake species, the Blackbelly garter snakes (Thamnophis melanogaster) and Tamaulipan montane garter snake (Thamnophis mendax) are listed as ‘Endangere’d and the Short-tail Alpine garter snake (Thamnophis scaliger) is listed as ‘Vulnerable’ on the IUCN red list. The rest of the Thamnophis genus are listed as Least Concern.
Garter Snakes As Pets
Garter Snakes are becoming increasingly popular as pets, and here’s why:
- Popularity: Their calm nature and ease of care make them a favorite among reptile enthusiasts.
- Ease of Care: Suitable for beginners, they don’t have complex needs.
- Licence: Most places don’t require a license, but always check local regulations.
- Equipment: A spacious terrarium, a water dish, a heat source, and hiding spots are essential for their well-being.
- Space: Garter snakes, though classed as medium, can reach over a meter long. This isn’t big for a snake and no surprise to the experienced keeper, but might be a bit alarming to the novice. So make sure you have done your homework if taking one on as a pet!
5 Fun Garter Snakes Facts for Kids
- Garter Snakes have a “third eye” on top of their head, known as the parietal eye.
- They can absorb oxygen through their skin when underwater.
- Some species can climb trees and shrubs with ease.
- If threatened, they might release a stinky musk to deter predators.
- Baby Garter Snakes are independent from birth and start hunting almost immediately!
Garter Snake Species Table
| Species | Subspecies | Location | Description |
| Aquatic garter snake – Thamnophis atratus | Santa Cruz garter snake, T. a. atratus | Coastal central California | Dark and robust with a broad head. |
| Oregon garter snake, T. a. hydrophilus | Central Valley of California | Often found near water. | |
| Diablo Range garter snake, T. a. zaxanthus | Central California | Yellowish stripe down the back. | |
| Bogert’s garter snake – Thamnophis bogerti | – | Oaxaca, Mexico | – |
| Shorthead garter snake – Thamnophis brachystoma | – | Western New York and northwestern Pennsylvania | Short and stout with a small head. |
| Butler’s garter snake – Thamnophis butleri | – | Great Lakes region | Small and secretive. |
| Goldenhead garter snake – Thamnophis chrysocephalus | – | Mexico | Golden-headed snake with a bright stripe. |
| Conant’s garter snake – Thamnophis conanti | – | Puebla and Veracruz, Mexico | – |
| Cope’s mountain meadow snake – Thamnophis copei Dugès | – | Mexico | Found in high-altitude meadows and grasslands. |
| Sierra garter snake – Thamnophis couchii | – | California and Oregon | Prefers riparian zones and wet meadows. |
| Blackneck garter snake – Thamnophis cyrtopsis | Western blackneck garter snake, T. c. cyrtopsis | Southwestern U.S., Mexico | Known as the Black-necked garter snake, often found near water. |
| Eastern blackneck garter snake, T. c. ocellatus | Eastern and central Mexico | Distinctive eye-like spots on the sides. | |
| Tropical blackneck garter snake, T. c. collaris | Southern Mexico | Inhabits tropical regions, often near water. | |
| Western terrestrial garter snake – Thamnophis elegans | Arizona garter snake, T. e. arizonae | Central Canada to Central U.S. | Versatile, found in various habitats from forests to grasslands. |
| Mountain garter snake, T. e. elegans | Western U.S. | Terrestrial snake often found in grassy areas. | |
| San Pedro Mártir garter snake, T. e. hueyi | Baja California | Limited distribution, specific habitat preferences unknown. | |
| Coastal garter snake, T. e. terrestris | Coastal California | Known as the Coast garter snake, vibrant colors. | |
| Wandering garter snake, T. e. vagrans | Western U.S. | Wandering garter snake, often found near water. | |
| Upper Basin garter snake, T. e. vascotanneri | U.S. Intermountain West | Prefers the high desert and mountain meadows. | |
| Mexican garter snake – Thamnophis eques | Mexican garter snake, T. e. eques | Central Mexico and in the United States (Arizona and New Mexico) | The nominal subspecies, it’s the most widespread of the T. eques group. Medium-sized with a distinct stripe pattern. |
| Laguna Totolcingo garter snake – T. e. carmenensis | Specific locations within Mexico | A subspecies with limited distribution, specific characteristics are less documented. | |
| T. e. cuitzeoensis | Mexico | Another subspecies with limited distribution | |
| T. e. diluvialis | Mexico | Found in certain regions of Mexico | |
| T. e. insperatus | Mexico | A subspecies with limited distribution | |
| Northern Mexican garter snake, T. e. megalops | Mexico | Distinct markings compared to other subspecies. | |
| T. e. obscurus | Northeastern Mexico | Prefers higher altitudes and cooler climates. | |
| T. e. patzcuaroensis | Mexico | Found in certain regions of Mexico | |
| T. e. scotti | Mexico | – | |
| T. e. virgatenuis | Mexico | – | |
| Mexican wandering garter snake – Thamnophis errans | – | Various states in Mexico including Chihuahua, Durango, Jalisco | Inhabits a variety of habitats, often near water. |
| Montane garter snake – Thamnophis exsul | – | Mexico | Found in high-altitude regions. |
| Fox’s mountain meadow snake – Thamnophis foxi | – | Mexico | Prefers mountain meadows and grasslands. |
| Highland garter snake – Thamnophis fulvus | – | Mexico, Guatemala, Honduras and El Salvador. | Found in the highlands, often near water. |
| Giant garter snake – Thamnophis gigas | – | Central California | One of the largest garter snakes, prefers wetlands. |
| Godman’s garter snake – Thamnophis godmani | – | Southern Mexico | Limited distribution |
| Two-striped garter snake – Thamnophis hammondii | – | California | Known as the Two-striped garter snake, prefers aquatic habitats. |
| Liner’s garter snake – Thamnophis lineri | – | Mexico | Limited distribution |
| Checkered garter snake – Thamnophis marcianus | T. m. marcianus | Southwestern U.S., Mexico | Checkered garter snake, often kept as pets. |
| T. m. praeocularis | Southwestern U.S., Mexico | – | |
| T. m. bovalli | Southwestern U.S., Mexico | – | |
| Blackbelly garter snake – Thamnophis melanogaster | Gray blackbelly garter snake, T. m. canescens | Central Mexico | Prefers cooler, high-altitude habitats. |
| Chihuahuan blackbelly garter snake, T. m. chihuahuanensis | Central Mexico | Prefers wetlands and riparian zones. | |
| Lined blackbelly garter snake, T. m. linearis | Central Mexico | Prefers wetlands and riparian zones. | |
| Mexican blackbelly garter snake, T. m. melanogaster | Central Mexico | Dark-colored with a distinct stripe pattern. | |
| Tamaulipan montane garter snake – Thamnophis mendax | – | Mexico | Found in mountainous regions. |
| Southern Durango spotted garter snake – Thamnophis nigronuchalis | – | Durango, Mexico | Limited distribution |
| Northwestern garter snakev – Thamnophis ordinoides | – | Pacific Northwest | Prefers coastal habitats, often found near water. |
| Tepalcatepec Valley garter snake – Thamnophis postremus | – | Mexico | Limited distribution |
| Western ribbon snake – Thamnophis proximus | Chiapas Highlands ribbon snake, T. p. alpinus | Central U.S. to Central America | – |
| Arid land ribbon snake, T. p. diabolicus | Central U.S. to Central America | – | |
| Gulf Coast ribbon snake, T. p. orarius | Gulf Coast | Coastal subspecies with a preference for marshy areas. | |
| Western ribbon snake, T. p. proximus | Central U.S. to Central Mexico | Known as the Orange Stripe Ribbon Snake, semi-aquatic. | |
| Redstripe ribbon snake, T. p. rubrilineatus | Texas | Known for its reddish stripes. | |
| Mexican ribbon snake, T. p. rutiloris | Central U.S. to Central America | – | |
| Yellow-throated garter snake – Thamnophis pulchrilatus | – | Mexico | Found in the highlands, often near streams. |
| Plains garter snake – Thamnophis radix | – | Central U.S. from Canada to Texas | Known as the Plains Garter Snake, prefers grasslands. |
| Rossman’s garter snake – Thamnophis rossmani | – | Mexico | Limited distribution |
| Narrow-headed garter snake – Thamnophis rufipunctatus | – | Soutwest US – Arizona, New Mexico and Mexico | Known as the Narrow-headed Garter Snake, prefers clear streams. |
| Ribbon snake – Thamnophis saurita | Bluestripe ribbon snake, T. s. nitae | Florida | Found in the Florida panhandle. |
| Southern ribbon snake, T. s. sackenii | Gulf Coast | Prefers coastal marshes and swamps. | |
| Eastern ribbon snake, T. s. saurita | Eastern U.S. | Known as the Eastern Ribbon Snake, semi-aquatic. | |
| Northern ribbon snake, T. s. septentrionalis | Northern U.S., Canada | Northern subspecies with a preference for cooler climates. | |
| Longtail alpine garter snake – Thamnophis scalaris | – | Mexico | Found in the highlands, often near rocky outcrops. |
| Short-tail Alpine garter snake – Thamnophis scaliger | – | Mexico | Prefers moist environments in the highlands. |
| Common garter snake – Thamnophis sirtalis | Eastern garter snake, T. s. sirtalis | Eastern North America | Recognized by its yellow or white stripe down the middle of its back and checkerboard pattern on its sides. |
| Red-sided garter snake, T. s. parietalis | As far north as Fort Smith, Northwest Territories, and as far south as the Oklahoma-Texas border | Features bright red or orange bars on its sides. | |
| California red-sided garter snake, T. s. infernalis | California coast | Vibrant blue or greenish-blue body with red bars on its sides. | |
| Red-spotted garter snake, T. s. concinnus | Northwestern Oregon and southwestern Washington | Has a series of red spots along its back. | |
| New Mexico garter snake, T. s. dorsalis | Mexico and southern New Mexico | Dark-colored snake with a distinct light-colored stripe down its back. | |
| Puget Sound garter snake, T. s. pickeringii | Northwestern Washington, Vancouver Island and the southwestern British Columbia | Light-colored stripe down its back with a checkerboard pattern on its sides. | |
| San Francisco garter snake, T. s. tetrataenia | San Mateo County, California | Known for its strikingly beautiful colors; blue-green body with red and black bands. | |
| Chicago garter snake, T. s. semifasciatus | Chicago, Illinois | Similar to the eastern garter snake but with a more pronounced checkerboard pattern. | |
| Maritime garter snake, T. s. pallidulus | Northeastern New England, Quebec, and the Maritime provinces | Lighter in color with a less distinct stripe down its back. | |
| Texas garter snake, T. s. annectens | Texas, Oklahoma and Kansas | Dark-colored snake with a distinct yellow or white stripe. | |
| Valley garter snake, T. s. fitchi | Rocky Mountains and interior ranges | Dark-colored with a distinct light-colored stripe and less pronounced checkerboard pattern. | |
| Blue-striped garter snake, T. s. similis | Northwestern peninsular Florida | Features three light blue stripes along its body. | |
| T. s. lowei | Chihuahua, Mexico | Similar to the Texas garter snake but found in the highlands of Mexico. | |
| Sumichrast’s garter snake – Thamnophis sumichrasti | – | Mexico | Found in the highlands, prefers moist environments. |
| Madrean narrow-headed garter snake – Thamnophis unilabialis | Mexico | Found in mountainous regions. | |
| West Coast garter snake – Thamnophis validus | Mexican Pacific Lowlands garter snake, T. v. celaeno | Baja California, Mexico | Known as the Baja California Garter Snake, prefers coastal areas. |
| T. v. isabellae | Mexico | – | |
| T. v. thamnophisoides | Mexico | – | |
| West Coast Garter Snake, T. v. validus | Mexico | – |
