Eastern Gartersnake

Thamnophis sirtalis sirtalis

written by Adam Mann

 

Mating pair of Gartersnakes: Female (larger) and Male (smaller)
Photo by Adam Mann

Natural History

Description:

Eastern Gartersnakes are medium sized non-venomous snakes that can attain lengths up to 4 feet.  They are highly variable in color and pattern, but most have three light colored stripes that run the length of the darker green or brown colored body.  If present, the lateral stripes are on scale rows 2 and 3.  Some individuals may possess more of a checkered pattern of black and green spots between the stripes (Mitchell, 1994).  The venter is cream or yellow with no obvious pattern.  Each ventral scale usually possesses one or more dark spots on each side.  The body scales are strongly keeled and the anal plate is not divided.

Similar Species:

Eastern Gartersnakes are most often confused with Common Ribbonsnakes, mainly due to the pattern consisting of 3 stripes that run the length of the body.  Ribbonsnakes have very distinct yellow stripes, including two lateral stripes that are found on each side of the body on scale rows 3 and 4.  They also have a consistent dark brown background color.  They are usually smaller and more slender, with a tail that comprises approximately one third the total length.  In West Virginia, Ribbonsnakes are much less common than Gartersnakes.

Habitat and Habits:

Eastern Gartersnakes are very common in many types of habitats, including urban areas.  They are often seen associated with wet habitats, but can also be found in open pastures and deep forests  (Conant and Collins, 1998).  They are opportunistic feeders, engulfing anything small enough to swallow.  Since they are not constrictors, they tend to eat more invertebrates and cold-blooded prey.  They have also been known to feed heavily on small fish.  Gartersnakes are very cold tolerant, staying active almost every month of the year.  They are usually the first reptiles to emerge from hibernation and the last to become dormant.  They overwinter in communal dens, often with other species of snakes.

Reproduction:

Eastern Gartersnakes mate soon after emerging from hibernation in the spring, but have been known to mate in the fall.  Males rely heavily on chemical cues in order to track and court an available female.  In some instances, many male snakes can be found trying to mate with one female (Green and Pauley, 1987).  Gartersnakes are viviparous, carrying the offspring until development is complete.  The small snakes are born between June and August, depending on the ambient temperature that year.  Litter sizes vary greatly, from 7 to 100 offspring.  The average litter size is between 10 and 20, but is also dependent on the size of the gravid female.  Snakes reach maturity after about 2 years.

Distribution

Eastern Gartersnakes can be found throughout the eastern half of North America, from southern Canada to the Gulf of Mexico.  They are the most common snakes found in West Virginia, with records from almost all counties.  Due to their cold tolerance, they have been found up to the highest elevations, and are considered the most common snake above 3,500 feet (Green and Pauley, 1987).

Status

The Eastern Gartersnake is extremely common and prolific.  Thus, it is not listed as rare, threatened or endangered on the state or federal level.

Interesting Facts

1)  Gartersnakes receive their common name from the striped garters that men used to wear to hold their socks up.  The genus Thamnophis actually means “bush snake.”  The species name sirtalis means “striped,” also referring to the longitudinal stripes running the length of the body.

2)  The name “Gartersnake” is often mispronounced as “Garden Snake” due to the close spelling as well as the snake’s common association with backyard habitats around homes. 

References

Conant, Roger, and Joseph Collins.  1998.  A Field Guide to Reptiles and Amphibians: Eastern/Central North America.  New York: Houghton Mifflin Company.

Green, N. Bayard, and Thomas K. Pauley.  1987.  Amphibians and Reptiles in West Virginia.  Pittsburgh: University of Pittsburgh Press.

Mitchell, Joseph C.  1994.  The Reptiles of Virginia.  Washington, DC: Smithsonian Institution Press.

 


    

Page created by Adam Mann
Last Updated - April 2003
Questions or comments on the web site?  Email Dr. Thomas K. Pauley at pauley@marshall.edu