Species: Thamnophis sirtalis

Common Gartersnake

Species

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Encyclopedia of Puget Sound

of Texas-Oklahoma), 7 scales on each upper lip, 1 preocular (scale in front of eye), 3 postoculars (scales behind eye), keeled scales on the back, and an undivided anal scale (covers vent). Adult total length is usually 16-26 inches (41-66 cm), with the maximum around 52 inches) (131 cm). Newborns are around 5-7 inches (12-23 cm) in total length (Conant and Collins 1991, Smith and Brodie 1982).

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Reptilia

Order

Squamata

Family

Colubridae

Genus

Thamnophis

NatureServe

Source:
ELEMENT_GLOBAL.2.101158

Classification

Other Global Common Names

Common Garter Snake - Red-sided Gartersnake - couleuvre rayée

Informal Taxonomy

Animals, Vertebrates - Reptiles - Snakes

Formal Taxonomy

Animalia - Craniata - Reptilia - Squamata - Colubridae - Thamnophis - Boundy and Rossman (1995) pointed out some nomenclatural problems among Pacific coast populations and suggested that populations now known by the name THAMNOPHIS SIRTALIS TETRATAENIA be referred to as T. S. INFERNALIS and that populations recently known as T. S. INFERNALIS be included within T. S. CONCINNUS. ICZN (2000) rejected this change, designated a neotype for T. S. INFERNALIS, and conserved the traditional subspecific taxonomy.

Ecology and Life History

Migration

false - true - false - In some areas in the northern part of the range, common gartersnakes make long migrations between winter hibernacula and summer range (up to at least 16 km between winter hibernaculum and summer range in at least some northern localities; Fitch 1980). In Manitoba, females dispersed from a communal den in all directions, rather than following distinct migration corridors (Shine et al. 2001).

Non-migrant

false

Locally Migrant

true

Food Comments

Preys chiefly on earthworms, frogs, toads, salamanders, and fishes; less regularly on slugs, leeches, small mammals and birds; rarely on insects, spiders, and small snakes (Fitch 1980).

Reproduction Comments

In much of the range, mating occurs primarily in spring, just after emergence from hibernation, though possibly to a limited extent also in late summer. Adult females give birth usually in July or August but earlier in the south and as late as early October in the north. Litter size averages about 13-26 but varies geographically (generally larger in the east than in the west); the largest females tend to produce the largest litters. Individuals become sexually mature in 1-2 years. In Northwest Territories, Canada, females evidently rarely gave birth in successive years (Larsen et al. 1993). See Cover and Boyer (1988) for information on captive breeding.

Ecology Comments

Home range size variously reported as 0.8 ha to 14 ha (DeGraaf and Rudis 1983). In the far northern part of the range, thousands may aggregate at hibernacula. Population density estimates in different areas range from about 10/ha to 100/ha.

Length

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

2006-08-22

Global Status Last Changed

2001-12-11

Distribution

Conservation Status Map

Global Range

H - >2,500,000 square km (greater than 1,000,000 square miles) - H - The wide range includes much of North America, from southeastern Alaska, British Columbia, southern Northwest Territories, northern Saskatchewan, central Manitoba, Ontario, central Quebec, and the Maritime Provinces to southern California, central Utah, northeastern Colorado, New Mexico and Chihuahua (disjunct), Texas, Gulf Coast, and southern Florida (Conant and Collins 1991, Ernst and Ernst 2003, Stebbins 2003).

Global Range Code

Global Range Description

>2,500,000 square km (greater than 1,000,000 square miles)

ELEMENT_GLOBAL.2.101158