Terrestrial Garter Snake
Thamnophis elegans
![[Terrestrial Garter Snake]](/images/56ds.jpg)
Description
Physical
A medium sized slender snake, adults rarely exceed 90cm (36 inches). Scales are keeled, single anal plate. Typically has 8 upper labials, the 6th and 7th are grossly enlarged compared to the 5th. Rear and front chin shields are approximately equal in length. Internasals are wider than long and rounded at the front. Pupils are round.
Color and Pattern
In our area, these snakes typically have a dark base color with a broad yellow or orange dorsal stripe and two broad cream to yellow side stripes where the dorsal scale rows meet the belly scales (one stripe on each side.)
Belly is plain, tongue is red with black tip.
Young are patterned like adults.
Sexual Dimorphism
Males tend to have longer tails that are noticeably fat after the vent, females have slightly shorter tails that taper off quickly after the vent. Some people are quite accurate at determining sex by tail geometry, but probing is required for most of us to be certain.
Habitat
Rarely found far from water, though it usually does not enter water and is not as adept at swimming as our other garter snake species. When threatened, it prefers to take cover in rocks or vegetation.
Diet
An opportunistic feeder, they primarily feed upon frogs and toads, small lizards and snakes, and small rodents. They are not as adept at catching aquatic prey as other garter snake species, but they will eat fish when they can, and often can be found in summer hanging around drying pools of temporary streams that have trapped fish in them.
Young often feed upon earthworms and Central Pacific Chorus Frogs (personal observation).
Distribution Range
General range map taken from CWHR.
Museum records taken from following institutions: CAS Herps, CAS-SUR, MVZ Herps, LSUMZ Herps.
Found throughout Shasta County.
Typical Elevation
Based on records in our database, in Shasta County the Terrestrial Garter Snake is typically found at all elevations up to 1632m (5352ft). Maximum elevation we have a record for is 1737m (5697ft).
Reproduction and Young
Mating takes place in the spring to early summer. Females give live birth to 4 to 19 young usually in late summer.
Taxonomy
The subspecies that occurs in our area is the Mountain Gartersnake (Thamnophis elegans elegans).
Pronunciation
The assumed IPA pronunciation of this species: /θɑm ˈnɑ fis/ /ɛl i gɑns/
Taxonomic Etymology
Thamnophis is a concatenation of two Greek words. θάμνος means shrub or bush. όφις means snake. It is a reference to the tendency of these snakes to be found in the vicinity of bushes.
elegans is from the Latin ēlegāns and indicates fine or elegant.
Taxonomy Notes
Additional Information
Images
Unless otherwise noted, all images are of wild specimens in Shasta County.
Please be kind, do not hotlink images and do not use images without permission of the copyright owner.
![[Terrestrial Garter Snake]](/images/1sm.jpg)
![[Terrestrial Garter Snake]](/images/3sm.jpg)
![[Terrestrial Garter Snake]](/images/4sm.jpg)
©Watermark Testing
Notice that the front chin shields are the same length as the rear chin shields. Redding, CA
![[Terrestrial Garter Snake]](/images/5sm.jpg)
![[Terrestrial Garter Snake]](/images/44sm.jpg)
©Watermark Testing
Notice that the internasals (two scales at very front of head) are wider than they are long and are rounded at the front. Redding, CA
![[Terrestrial Garter Snake]](/images/56sm.jpg)
©Watermark Testing
Juvenile. Found near pool that contained small fish, Central Pacific Chorus Frog tadpoles, and recently transformed Central Pacific Chorus Frogs. Sulfur Creek. Redding, CA
Habitat Shots
Unless otherwise noted, these habitat shots are from within Shasta County where this species is known to occur.
![[Terrestrial Garter Snake habitat]](/images/2sm.jpg)
©Watermark Testing
While you can not see it in the photograph, Sulfur Creek is directly behind the trees. Terrestrial Garter Snakes are usually found near a source of water, but readily venture away from the water. Redding, CA
![[Terrestrial Garter Snake habitat]](/images/111sm.jpg)
©Watermark Testing
A Terrestrial Garter Snake was spotted in the pool at the bottom of the waterfall in the reeds where it likely was looking for adult Central Pacific Chorus Frogs to feed upon. This habitat may also have Foothill Yellow-legged Frogs for them to feed upon, though none were seen. Redding, CA.
Similar Species
Aquatic Garter Snake
Aquatic Garter Snakes (Thamnophis atratus) in our area usually have a weak or missing dorsal stripe. Their 6th and 7th upper labial is not grossly enlarged compared to the 5th. Their internasals are longer than they are wide and pointed in the front.
Sierra Garter Snake
Sierra Garter Snakes (Thamnophis couchii) usually have a weak or missing dorsal stripe. Their 6th and 7th upper labial is not grossly enlarged compared to the 5th. Their internasals are longer than they are wide and pointed in the front.
Common Garter Snake
Common Garter Snakes (Thamnophis sirtalis) in our area usually has noticable red blotches on side and typically only has 7 upper labials.
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