Common garter snake
Thamnophis sirtalis annectens (Texas garter snake)
Thamnophis sirtalis concinnus (Red-spotted garter snake)
Thamnophis sirtalis dorsalis (New Mexico garter snake)
Thamnophis sirtalis fitchi (Valley garter snake)
Thamnophis sirtalis infernalis (California red-sided garter snake)
Thamnophis sirtalis lowei (Chihuahua garter snake)
Thamnophis sirtalis pallidulus (Maritime garter snake)
Thamnophis sirtalis parietalis (Red-sided garter snake)
Thamnophis sirtalis pickeringii (Puget Sound garter snake)
Thamnophis sirtalis similis (Blue-striped garter snake)
Thamnophis sirtalis sirtalis (Eastern/Common garter snake)
Thamnophis sirtalis semifasciatus (Chicago garter snake)
Thamnophis sirtalis tetrataenia (San Francisco garter snake)
Thamnophis sirtalis annectens – From eastern central-Texas to western Central Oklahoma into eastern Panhandle (Texas) and south-western Kansas.
Thamnophis sirtalis concinnus – From south-western Washington southward through north-western Oregon into southern California.
Thamnophis sirtalis dorsalis – Southern New Mexico along the Rio Grande. A second population lives in north-western Chihuahua (Mexico).
Thamnophis sirtalis fitchi – From southern British Columbia (except the south-west coast and Vancouver Island) southward through Idaho and eastern Washington, eastward into the central part of northern Utah and Oregon and westward into central California. Between Monterey and Santa Barbara they reach the coast and penetrates here the habitat of T. sirtalis concinnus.
Thamnophis sirtalis infernalis – The peninsula of San Francisco.
Thamnophis sirtalis lowei – Some isolated populations in west-central Chihuahua.
Thamnophis sirtalis pallidulus – Northern New England, southern Quebec and the Maritime Provinces of Canada.
Thamnophis sirtalis parietalis – Central into south-eastern British Columbia, Alberta and the adjacent section of McKenzie, central Saskatchewan, Manitoba, and south across the Great Plains into the border of Texas/Oklahoma.
Thamnophis sirtalis pickeringii – On Vancouver Island, on the south-western coast of British Columbia and the western third of Washington.
Thamnophis sirtalis semifasciatus – North-eastern Illinois and in the adjacent part of south-eastern Wisconsin, as well as in northwestern Indiana.
Thamnophis sirtalis similis – North-western coast of Florida, from Walkulla County to Withlacoochee.
Thamnophis sirtalis sirtalis – Southern New England and southern Canada southward into Florida and southeastern Texas.
Thamnophis sirtalis tetrataenia – The western part of the San Francisco Peninsula, from San Francisco County along the coast to San Mateo County, California.
Lives in a wide range of habitats. Both near and far away from water, in open areas, forest areas and even in cities.
Fish, amphibians, lizards, invertebrates, mammals and birds. Sometimes they even eat snakes and also there are cases known of bird eggs devoured in a nest.
Usually the copulations take place rather immediately after the end of the brumation, usually in March and April. The young are born from mid summer to early autumn. A litter consists of a few dozen young (also dependent on the subspecies) to a maximum of about 85 young. These are approximately between 15 and 22 cm in length and weigh 2 to 4 grams at birth.
In places where males and females live together throughout the whole year also two litters per year occur.
For this species, a large terrarium is required when several adult animals are kept together. Place a water bowl in the terrarium that is big enough for all snakes to lie in together. Some shelters and climbing branches complete the terrarium.
All info listed below is “general” for the species. This can be different for each subspecies.
Average length lies between 70 and 100 cm, with a maximum of about 140 cm.
This species occurs at altitudes between 0 and 2540 meters.
Common garter snakes are generally active during the day, but switch effortlessly to nocturnal activity when it is too hot during the day.
In the north of the distribution area, the snakes are active about 200 to 220 days per year while the snakes of this species in the south sometimes active the whole year.
Thamnophis sirtalis tetrataenia is considered one of the most beautiful snakes in the United States, but is also one of the most endangered snakes there.
Thamnophis sirtalis lowei is also considered as an isolated population of Thamnophis sirtalis dorsalis.
Of Thamnophis sirtalis sirtalis black (melanistic) specimens are known throughout the range, but in the area of Lake Erie the concentration is much higher than elsewhere. In other subspecies, like for example, T. s. parietalis and T. s. similis, melanistic specimen are also known.
In Manitoba Thamnophis sirtalis parietalis brumates en masse and in spring they, en masse, participate in reproductive activities. Here you can find more about this phenomenon.
Take a look at one of the books on this page for more info about the different subspecies.