Eastern garter snake

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Eastern garter snake
Thamnophis sirtalis sirtalis Wooster.jpg
Status TNC T5.svg
Secure  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Thamnophis
Species:
Subspecies:
T. s. sirtalis
Trinomial name
Thamnophis sirtalis sirtalis
(Linnaeus, 1758)

The eastern garter snake (Thamnophis sirtalis sirtalis) is a medium-sized snake indigenous to North America.

Contents

Taxonomy

Etymology

The scientific name Thamnophis sirtalis sirtalis is a combination of Ancient Greek and New Latin that means "bush snake that looks like a garter strap". The generic name Thamnophis is derived from the Greek "thamnos" (bush) and "ophis" (snake) and the specific name sirtalis is derived from the New Latin "siratalis" (like a garter), a reference to the snake's color pattern resembling a striped garter strap. [2]

Anatomy and description

Eastern garter snakes average between 46–66 cm (18–26 in) long. The largest recorded length was 124 cm (48.7 in) long. Females are typically larger than males. They are either a greenish, brown, or black color and have a distinct yellow or white stripe.

The eastern garter snake is broadly considered non-venomous. Garter snakes do have a Duvernoy's gland, and the secretion from the gland may be chewed into prey during bites. The secretion is noted to cause hemorrhaging in mice and has produced non-allergic symptoms in at least one bite on a human. [3] [4] [5]

Distribution and habitat

The eastern garter snake has a wide range across eastern North America and as far north as southern Ontario and Quebec to the Gulf of Mexico in the south, along the eastern shores of America to the Mississippi River.[ citation needed ] Their distribution ranges all across America but tends not to be present in western deserts. [6] In New England, the snake is described as the "most widespread and ubiquitous" serpent, from wilderness to urban environments and from sea level to high elevations. [2]

The eastern garter snake will live in a variety of environments, with a preference for grassy or shrubby fields, including abandoned farmland, outbuildings and trash dumps. [2] In particular the snake likes to inhabit stone walls that separate the forest from fields. It is also found along moist habitats such as lakes, rivers, streams, swamps, bogs, ponds, drainage ditches, and quarries. Snakes are present in urban environments in habitats that include "city parks, cemeteries and suburban yards and gardens". [2] Eastern garter snakes like to conceal themselves under logs, stones and other debris that allow them to bask in the sunlight and quickly seek refuge from predators. Krulikowski notes that "old poultry farms with discarded sheet-metal incubation trays provide warm, moist hiding places." [2]

Eastern Garter Snake imported from iNaturalist photo 122620448 on 6 December 2024.jpg
Eastern Garter Snake imported from iNaturalist photo 183586093 on 6 December 2024 (cropped).jpg
Eastern Garter Snake imported from iNaturalist photo 189879310 on 6 December 2024.jpg
Eastern Garter Snake imported from iNaturalist photo 169352879 on 6 December 2024 (cropped).jpg
Eastern Garter Snake imported from iNaturalist photo 46623001 on 6 December 2024 (cropped).jpg
Eastern Garter Snake imported from iNaturalist photo 327649580 on 6 December 2024.jpg
Colour variation in the eastern garter snake

Ecology and behavior

Hunting and diet

An eastern garter snake eating a northern leopard frog (Lithobates pipiens). Eastern garter snake eating frog.jpg
An eastern garter snake eating a northern leopard frog (Lithobates pipiens).

The majority of the eastern garter snake's diet (~80%) consists of earthworms, though they have a secondary preference (~15%) for amphibian prey (esp. frogs) as well. [7] As they mature, their preference in prey will undergo an ontogenetic shift. Younger eastern garter snakes (those under 40 cm (16 in) in length) prey almost exclusively upon earthworms (~88%) and smaller amphibians (~8%), such as spring peepers and northern cricket frogs, and generally avoid taking warm-blooded prey. Mature snakes rely more on amphibian prey (which now comprise ~19% of their diet), especially larger amphibians like green frogs and northern leopard frogs, though earthworms still make up the bulk of their diet (~76%). [8]

However, eastern garter snakes are opportunistic predators, and will readily consume almost any creature they can swallow. Other prey records for this subspecies include caterpillars, [7] leeches, [9] mudminnows, [9] the Jefferson salamander, [10] and the eastern meadow vole. [11] Large adults will even target small birds if the opportunity presents itself, such as song sparrows, [12] goldfinches, [12] and chipping sparrows. [13]

Predator avoidance

The eastern garter snake is known to flatten its head and anterior body and strike forward if it is bothered. Juveniles have been observed to engage in this behavior and strike at such a force that they leave the ground entirely. Adults also will spray musk from glands in their tail, and sometimes defecate to discourage predators.[ citation needed ] Snakes with higher body temperatures are more likely to flee from predators. [14]

Reproduction

Eastern garter snakes are ovoviviparous, giving birth to live young. Many males may try to mate with one female, resulting in a "snake orgy".[ citation needed ] The young are 13–23 cm (5–9 in) long at birth.

Conservation status

Melanistic eastern garter snake Melanistic eastern garter snake (Thamnophis sirtalis ssp. sirtalis), Wellington North, Ontario, CA (99085233).jpg
Melanistic eastern garter snake

As of 2024, the eastern garter snake has not been assessed by the IUCN Red List, nor has it been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). [15] Its parent species, the common garter snake (Thamnophis sirtalis), was last assessed by the IUCN in 2007 and determined to be of least-concern due its wide geographic distribution, (presumed) large population, and lack of significant threats to its survival. [16] In 2016, NatureServe assessed the eastern garter snake to be a secure subspecies (G5T5) globally, and nationally secure (N5) in Canada. [1]

Related Research Articles

<span class="mw-page-title-main">Garter snake</span> Common name for North American snakes of the genus Thamnophis

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.

<span class="mw-page-title-main">Common garter snake</span> Species of snake

The common garter snake is a species of snake in the subfamily Natricinae of the family Colubridae. The species is indigenous to North America and found widely across the continent. There are several recognized subspecies. Most common garter snakes have a pattern of yellow stripes on a black, brown or green background, and their average total length is about 55 cm (22 in), with a maximum total length of about 137 cm (54 in). The average body mass is 150 g (5.3 oz). The common garter snake is the state reptile of Massachusetts.

<span class="mw-page-title-main">Wade Fox</span> American zoologist and herpetologist

Rufus Wade Fox Jr., was an American zoologist and herpetologist from the University of California, Berkeley. He specialized in the anatomy of snakes and the systematics of the western garter snakes.

<span class="mw-page-title-main">Rough-skinned newt</span> Species of amphibian known for strong toxicity

The rough-skinned newt or roughskin newt is a North American newt known for the strong toxin exuded from its skin.

<i>Thamnophis saurita</i> Species of snake

Thamnophis saurita, also known as the eastern ribbon snake, common ribbon snake, or simply ribbon snake, is a common species of garter snake native to Eastern North America. It is a non-venomous species of snake in the subfamily Natricinae of the family Colubridae. The ribbon snake averages 16 to 35 inches in total length. It is dark brown with bright yellow stripes. The ribbon snake is not sexually dimorphic; however, females are normally thicker than their male counterparts.

<span class="mw-page-title-main">San Francisco garter snake</span> Subspecies of snake

The San Francisco garter snake is a slender multi-colored subspecies of the common garter snake. Designated as an endangered subspecies since the year 1967, it is endemic to San Mateo County and the extreme northern part of coastal Santa Cruz County in California.

<span class="mw-page-title-main">Checkered garter snake</span> Species of snake

The checkered garter snake is a species of garter snake in the subfamily Natricinae of the family Colubridae. The species is endemic to the southwestern United States, Mexico, and Central America.

<span class="mw-page-title-main">Plains garter snake</span> Species of snake

The plains garter snake is a species of garter snake native to most of the central United States as far north as Canada and as far south as Texas. 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.

<span class="mw-page-title-main">Giant garter snake</span> Species of snake

The giant garter snake is the largest species of garter snake. Relatively rare, it is a semi-aquatic snake with a limited distribution in the wetlands of central California.

<span class="mw-page-title-main">Sierra newt</span> Species of amphibian

The Sierra newt is a newt found west of the Sierra Nevada, from Shasta county to Tulare County, in California, Western North America.

<span class="mw-page-title-main">Butler's garter snake</span> Species of snake

Butler's garter snake is a species of garter snake in the family Colubridae. The species is endemic to North America.

<span class="mw-page-title-main">Western terrestrial garter snake</span> Species of snake

The western terrestrial garter snake is a western North American species of colubrid snake. At least five subspecies are recognized.

The narrow-headed garter snake, Thamnophis rufipunctatus, is a species of nonvenomous garter snake that is endemic to the southwestern United States. Its common names also include narrowhead garter snake and narrowhead watersnake.

<span class="mw-page-title-main">Blackneck garter snake</span> Species of snake

Thamnophis cyrtopsis, the blackneck garter snake, is a species of garter snake of the genus Thamnophis. It is native to the southwestern United States, Mexico and Guatemala, and can be found in a wide range of different habitats, often near water sources.

<span class="mw-page-title-main">Shorthead garter snake</span> Species of snake

Thamnophis brachystoma, commonly known as the shorthead garter snake or short-headed gartersnake, is a small species of colubrid snake. The species is endemic to the north-eastern United States.

<span class="mw-page-title-main">California red-sided garter snake</span> Subspecies of snake

The California red-sided garter snake is a subspecies of the common garter snake. This slender subspecies of natricine snake is indigenous to North America and is one of three recognized subspecies of Thamnophis sirtalis found in California. While commonly confused with the subspecies T. s. concinnus, it is biologically part of the population of the subspecies T. s. tetrataenia, as pointed out by Boundy and Rossman (1995), but was preserved as T. s. infernalis as a neotype under ICZN code Article 75 in a 2000 decision by the International Commission on Zoological Nomenclature (ICZN) in 2000 in order to preserve the existing subspecies taxonomy.

<span class="mw-page-title-main">Blackbelly garter snake</span> Species of snake

The blackbelly garter snake is a species of snake of the family Colubridae. It is found in Mexico.

The Southern Durango spotted garter snake is a species of snake of the family Colubridae. It is endemic to the state of Durango, Mexico.

<span class="mw-page-title-main">Red-sided garter snake</span> Subspecies of snake

The red-sided garter snake is a subspecies of the common garter snake, in the subfamily Natricinae of the family Colubridae. This slender subspecies of natricine snake is indigenous to North America and is one of the recognized subspecies of Thamnophis sirtalis. This subspecies is widely spread across northern United States and southern Canada.

References

Citations

  1. 1 2 NatureServe 2016.
  2. 1 2 3 4 5 Krulikowski 2004.
  3. Hayes & Hayes 1985.
  4. Vest 1981.
  5. Gomez et al. 1994.
  6. Shine et al. 2004.
  7. 1 2 Carpenter 1952, p. 239: "The Common Garter Snake, while showing a preference for earthworms (80%), also has a secondary preference for amphibians (15%) and consumed a much greater variety of foods, including mammals, fish, caterpillars and leeches (Fig. 4)."
  8. Carpenter 1952, p. 239: "Common Garter Snakes exceeding 40 cm in length capture more amphibians and take more warm blooded prey than the smaller snakes: earthworms 76% and 88%, amphibians 19% and 8%, mammals 2% and 0%, others 3% and 4%, respectively. The amphibians eaten by the small snakes were all small forms (two Hyla crucifer, one Pseudacris nigrita, one Acris crepitans, and a metamorphosing Rana clamitans). Large Rana clamitans and Rana pipiens, made up 65% of the amphibians eaten by the larger snakes, suggesting that they choose these larger frogs."
  9. 1 2 Carpenter 1952, p. 241: "Six other individuals contained two or three types of food at one time in combinations of earthworms and mammal, earthworm and frog and another had eaten five mudminnows (Umbra limi), a tadpole and a leech."
  10. Carpenter 1952, p. 241: "A third disgorged an earthworm and a Jefferson Salamander (Ambystoma Jeffersonianum), one month later a Green Frog, and a little over one year later, three earthworms."
  11. Carpenter 1952, p. 242: "All of the mammals eaten were Microtus pennsylvanicus. Two were represented by the skull and fur, one by fur only, and the other by fur and newly born young."
  12. 1 2 Carpenter 1952, p. 242: "The first record [from the Common Garter Snake] for a bird was an adult Song Sparrow (Melospiza melodia) taken at the Fleming Creek area. There is no evidence to show whether it was dead or alive when taken. The other record was for four Goldfinch nestlings (Spinus tristis) taken in the field just east of the Cherry Hill area, but the Goldfinches may have been alive, as indicated by adult activity near the nest, though the condition of the nest led me to believe they were dead when eaten."
  13. Carpenter 1952, p. 242: "Walkinshow (1943) reports this species eating Chipping Sparrows (Spizella passerina)."
  14. Passek & Gillingham 1997.
  15. Ontario Nature 2024: "Neither the Committee on the Status of Species at Risk in Ontario nor the Committee on the Status of Endangered Wildlife in Canada has assessed the status of the eastern gartersnake. [...] The International Union for Conservation of Nature has not yet assessed the global status of the eastern gartersnake, but lists the common gartersnake (of which the eastern gartersnake is a subspecies) as Least Concern."
  16. Frost, Hammerson & Santos-Barrera 2007: "Listed as Least Concern in view of its extremely wide distribution, presumed large population, and because populations are unlikely to be declining."

Bibliography

  • Carpenter, Charles C. (October 1952). "Comparative Ecology of the Common Garter Snake (Thamnophis s. sirtalis), the Ribbon Snake (Thamnophis s. sauritus), and Butler's Garter Snake (Thamnophis butleri) in Mixed Populations". Ecological Monographs. 22 (4). Wiley: 235–258. doi:10.2307/1948469. JSTOR   1948469.
  • Krulikowski, Linda (2004). Snakes of New England / Photographic and Natural History Study. Luvlife Publishing. pp. 72–84. ISBN   978-0976431602.