Tropidoclonion lineatumLined Snake

Geographic Range

Lined snakes are found in the Great Plains states, with their range snake extending from southeastern South Dakota to Texas. Disjoint populations also occur in New Mexico, eastern Colorado, southeast Iowa, and central Illinois. There are four recognized subspecies of lined snake. These include the central lined snake Tropidoclonion lineatum annectens, northern lined snake Tropidoclonion lineatum lineatum, Merten's lined snake Tropidoclonion lineatum mertensi, and the Texas lined snake Tropidoclonion lineatum texanum. (Conant and Collins, 1991; Ramsey, 1953)


Lined snakes are found in a variety of habitats, including open prairies, the edges of woodlands and sparsely wooded areas, vacant lots, and residential areas. They hibernate during winter months in the crevices of rocky outcroppings. Individuals have been found to hibernate at a depth of 6 to 8 inches. (Conant and Collins, 1991; LeClere, 2011; Ramsey, 1953; "Northern Prairie Wildlife Research Center", 2006)

  • Range elevation
    1828 (high) m
    5997.38 (high) ft

Physical Description

This species is a relatively small and slender. The head is small, barely wider than the body. Adults range in size from 22 to 38 cm (8.7 to 15 inches). A variety of body colorations are present, from olive- to gray-brown. Down the middle of the back, there is a light stripe that varies in color from white to orange. There are two additional stripes along the sides. The ventral belly scales are white, with two rows of black, half moon-shaped scales down the center. ("MN Department of Natural Resources", 2011; "Tropidoclonion lineatum -- Lined Snake", 2009; Conant and Collins, 1991; Ramsey, 1953; Smith, 1965; "Northern Prairie Wildlife Research Center", 2006)

Western ribbon snakes (Thamnophis proximus proximus) resemble lined snakes, and show significant overlap in their geographical distribution. However, ribbon snakes lack the double row of black half-moon scales on their belly. Lined snakes are distinguished from crayfish snake species (genus Regina), whose color pattern also shows some resemblance, by having keeled dorsal scales and an undivided anal plate. ("MN Department of Natural Resources", 2011; "Tropidoclonion lineatum -- Lined Snake", 2009; Conant and Collins, 1991; Ramsey, 1953; "Northern Prairie Wildlife Research Center", 2006)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    22 to 38 cm
    8.66 to 14.96 in


Young are born fully formed, resembling smaller versions of adults. Like most snakes, they grow throughout their entire lives. ("MN Department of Natural Resources", 2011)


Little is known regarding the specifics of mating systems in lined snakes. In related species of the genus Thamnophis, females become unattractive to sexually active males for at least 48 hours following copulation, due to the secretion and insertion of a mating plug by the previous male. This inhibition of courtship behavior minimizes the probability of multiple inseminations of his female mate. Extracts from female Thamnophis species act as pheremones, and will elicit courtship behavior from males, even when applied to other male individuals. (Garstka, 1981; Ross, 1978)

Female lined snakes reach sexual maturity at an age of 2 years. At this point, females may produce eggs which develop inside the body. Lined snakes breed in the fall, but fertilization is delayed until the spring, with birth occurring in August. The live young are independent at birth. ("MN Department of Natural Resources", 2011)

  • Breeding interval
    Lined snakes breed once yearly in the spring.
  • Breeding season
    Birth of live young occurs in late summer.
  • Range number of offspring
    2 to 12
  • Range gestation period
    3 to 5 months
  • Average age at sexual or reproductive maturity (female)
    2 years

As a viviparous species, a female lined snake provides nutrients and protection to her offspring as they develop inside her body. The young are born fully independent, and no post-birth parental investment occurs. ("MN Department of Natural Resources", 2011)

  • Parental Investment
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female


There are several major factors that limit the lifespan of lined snakes. They are highly susceptible to mortality on busy roads, as well as from the loss of preferred habitat due to agricultural cultivation, livestock grazing, and residential or commercial development. Lifespan information for this species could not be found. Average lifespan in the closely related genus Thamnophis is between 3 to 10 years. ("MN Department of Natural Resources", 2011; Garstka, 1981)


Lined snakes are active from March to November. They overwinter in rock crevices and animal burrows that are located below the frost line. After hibernation, they emerge in March or April. They spend the most time at the surface during the cooler spring months (especially after heavy rains), spending more time in their dens during the hot summer months. These snakes are primarily nocturnal, although they may bask during the day in early spring and late fall when temperatures are not too high. They are often solitary, but it is not uncommon to find several snakes together. If these snakes are left undisturbed by humans they will make no effort to escape but if molested, they will thrash and exude musk. One case of cannibalism has been documented in captive individuals. ("MN Department of Natural Resources", 2011; "Tropidoclonion lineatum -- Lined Snake", 2009; Force, 1931)

  • Range territory size
    1,500 to 3,400 m^2

Home Range

Information regarding the home range of lined snakes is not currently available. The summer home range of garter snakes (Thamnophis) averages 1,500 m^2, while the winter home range averages 3,400 m^2. However, this information came from populations in California, where lined snakes do not occur, and its applicability to this species is thus questionable. This is particularly true in the case of winter ranges, as this species hibernates during these months. ("MN Department of Natural Resources", 2011; Zeiner, 1990)

Communication and Perception

Snakes perceive their environment through a number of sensory channels, primarily relying upon sight, ground vibrations, taste, and smell. Female snakes release pheromones that elicit male courtship behavior. Males secrete a mating plug that is produced from their renal sex segment, and is able to be sensed by other males, inhibiting their courtship behaviors and minimizing the probability of multiple inseminations of mated females. (Garstka, 1981; Ross, 1978; Zeiner, 1990)

Food Habits

Lined snakes mainly feed on earthworms (Lumbricus terrestris). They usually forage at night or after a rainstorm, when earthworms are most active. Their secondary diet has also been recorded to include sow bugs (Oniscus asellus), snails (Helix aspersa), slugs, and soft-bodied insects. ("MN Department of Natural Resources", 2011; LeClere, 2011)

  • Animal Foods
  • terrestrial non-insect arthropods
  • mollusks
  • terrestrial worms


Lined snakes are preyed upon by carnivorous mammals and a variety of birds. This species possesses cryptic coloration as an anti-predator adaptation and is also very secretive, hiding under various surfaces, which further helps to reduce predation. ("MN Department of Natural Resources", 2011)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Lined snakes are both predators and prey in their ecosystems. ("MN Department of Natural Resources", 2011)

Economic Importance for Humans: Positive

Lined snakes have little economic importance to humans, although similar species (i.e. garter snakes) are popular in the pet trade. (Kaplan, 2009)

Economic Importance for Humans: Negative

Lined snakes have been forced out of their preferred habitat in some areas, being pushed into residential and commercial areas. While they could possibly bite, they are non-venomous and the bite would have no lasting affect on a human, barring any allergies to the snake's saliva. ("MN Department of Natural Resources", 2011)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Although they are susceptible to mortality on busy roads and face habitat loss in some areas, populations of this species throughout its range appear to be stable, and it is not currently listed as threatened or endangered by any regulatory body. ("MN Department of Natural Resources", 2011)


Keri O'Keefe (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Jeremy Wright (editor), University of Michigan-Ann Arbor, Catherine Kent (editor), Special Projects.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


an animal that mainly eats meat


uses smells or other chemicals to communicate


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

delayed fertilization

a substantial delay (longer than the minimum time required for sperm to travel to the egg) takes place between copulation and fertilization, used to describe female sperm storage.

female parental care

parental care is carried out by females


union of egg and spermatozoan


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.


the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night

pet trade

the business of buying and selling animals for people to keep in their homes as pets.


chemicals released into air or water that are detected by and responded to by other animals of the same species


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


movements of a hard surface that are produced by animals as signals to others


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


2011. "MN Department of Natural Resources" (On-line). Tropidoclonion lineatum. Accessed April 03, 2011 at

United States Geological Survey. 2006. "Northern Prairie Wildlife Research Center" (On-line). Fragile legacy: Endangered, Threatened, and Rare Animals of South Dakota. Accessed April 03, 2011 at

Illinois Natural History Survey. Tropidoclonion lineatum -- Lined Snake. 2009. Urbana-Champaign: University of Illinois. 2009. Accessed April 03, 2011 at

Conant, R., J. Collins. 1991. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Third Edition, Expanded. New York, NY: Houghton Mifflin Company.

Force, E. 1931. Habits and Birth of Young of the Lined Snake, Tropidoclonion lineatum. Copeia, 2: 51-53.

Garstka, W. 1981. Female sex pheromone in the skin and circulation of garter snake. Science, 214: 681-683.

Kaplan, M. 2009. "HerpCare Collection" (On-line). Garter Snakes: an overview of their natural history and care in captivity. Accessed April 26, 2011 at

LeClere, J. 2011. "Amphibians and Reptiles of Minnesota" (On-line). Lined Snake-Tropidoclonion lineatum. Accessed April 04, 2011 at

MacRae, M. 2008. "Canadian Wildlife Federation" (On-line). Common Garter Snake. Accessed April 26, 2011 at

Ramsey, L. 1953. The Lined Snake, Tropidoclonion lineatum. Herpetologica, 9: 7-24.

Ross, P. 1978. Stimuli Influencing Mating Behavior in the Garter Snake, Thamnophis radix. Behavioral Ecology and Sociobiology, 4: 133-142.

Smith, H. 1965. Two New Colubrid Snakes from the United States and Mexico. Journal of the Ohio Herpetological Soceity, 5: 1-4.

Zeiner, D. 1990. Life history accounts for species in the California Wildlife habitat relationships. California's Wildlife, 1: 1-3.