Thamnophis butleri
Butler's garter snake

Butler's garter snakes are found in the southern Great Lakes region and into Indiana and Illinois. There are isolated populations in southern Wisconsin and southern Ontario. Throughout its range, Butler's garter snakes are often found in isolated populations as their preferred habitats are increasingly fragmented by human habitat destruction. (Behler and King, 2000; Conant and Collins, 1998; Harding, 1997; Holman et al., 1999)

Butler's garter snakes prefer wet meadows and prairies. They are often found near marshy ponds and lake borders. These kinds of habitats sometimes occur in suburban and urban areas and relatively large concentrations of Butler's garter snakes can be found in those areas. Specific habitat preferences may help to reduce competition with their close relatives, eastern garter snakes and northern ribbon snakes. (Behler and King, 2000; Conant and Collins, 1998; Environment Canada, 2002; Harding, 1997; Holman et al., 1999; Toronto Zoo, 2002)

Butler's garter snakes are small, stout garter snakes with three well-defined yellow or orange stripes that run along the length of their body on a background color of black, brown, or olive. They sometimes have two rows of dark spots running between their central stripe and the two side stripes. Their head is relatively narrow, not much wider than their body, and their scales are keeled (with a ridge along the length of the scale). Their belly color is pale green or yellow with black spots running along the edges. Adults reach a total length of from 38 to 73.7 cm. There are 19 scale rows total and the anal plate is single.

Male snakes are slightly smaller than females, and have slightly longer tails. Young Butler's garter snakes are born at from 12.5 to 18.5 cm.

Other garter snakes have somewhat longer and larger heads than do Butler's garter snakes. Other sympatric garter snake species can be distinguished from Butler's garter snakes by the position of the lateral (side) stripes relative to the dorsal scale rows. One must count the scale rows from the ventral scales to the dorsal scale row and note on which row of scales the stripes occur. In Butler's garter snakes, the stripe is found on the third scale row, and also runs partially onto the upper part of the second row of scales and the lower part of the fourth scale row. In contrast, eastern garter snakes have stripes confined to scale rows 2 and 3. Often, juveniles are more distinctly marked than adults. (Behler and King, 2000; Conant and Collins, 1998; Environment Canada, 2002; Holman et al., 1999; Toronto Zoo, 2002)

The potential lifespan of Butler's garter snakes is unknown. The highest recorded lifespan in captivity is 14 years, average captive lifespans range from 6 to 10 years. Most wild individuals probably do not live as long as this due to predation and environmental stresses (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999)

Butler's garter snakes are active generally from late March to October or November of each year. They are most often seen in spring and fall and may become nocturnal during the summer months. They retreat to underground hibernation sites during cold weather, often in rodent or crayfish burrows or in natural cavities or under rock piles. These are secretive snakes and they are mainly active underground. Butler's garter snakes are mostly solitary, though they congregate at hibernation sites. They may occupy hibernation sites with eastern garter snakes as well.

Butler's garter snakes, like all snakes, are ectothermic and must maintain their body temperature by choosing different microhabitats for periods of time. They may be seen sunning themselves on rocks or bare ground, especially when they are digesting. They seek shelter in order to cool body temperatures. (American Psychological Association, 1989; Behler and King, 2000; Conant and Collins, 1998; Harding, 1997; Holman et al., 1999)

These are docile and shy animals. They most readily flee when approached and are not easily provoked to bite. (Harding, 1997)

All snakes have evolved special ways in which they perceive their environments. Their senses of taste and smell are combined by the use of a special organ, called the Jacobson's organ. This organ is composed of two specialized sensory pits located on the roof of the snakes' mouth. By flicking their tongues in and out rapidly, the snake transfers molecules from the air, as well as from things it may actually touch with its tongue, to the Jacobson's organ. This specialized sense is the way snakes gather and analyze most of the information from their environment. (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999)

Snakes are also highly tactile and sensitive to vibrations. Snakes have only an inner ear and they can probably detect low-frequency sounds. (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999; Toronto Zoo, 2002)

Compared to other snakes, garter snakes have relatively good vision. However, vision is not the primary way that they perceive their environment. (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999)

Garter snakes primarily communicate with each other through pheromones, which act to stimulate reproduction. Touch may play a role as well.

Butler's garter snakes eat mostly earthworms. They will also eat leeches, small frogs, and salamanders. (Behler and King, 2000; Conant and Collins, 1998; Environment Canada, 2002; Harding, 1997; Holman et al., 1999)

Butler's garter snakes are preyed upon by most predators throughout their range, including milk snakes, American crows, hawks, owls, raccoons, skunks, weasels, shrews, foxes, and domestic cats. They escape predation by attempting to escape. If harassed, though, they will exude a foul-smelling substance. If they are suddenly surprised they will thrash their bodies violently from side to side, perhaps to confuse predators and startle them in turn. (Harding, 1997)

Butler's garter snakes help to control populations of earthworms, leeches, and slugs. They also act as important food sources for their predators where they are abundant. They are parasitized by certain species of trematodes. (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999)

There are no known adverse affects of Butler's garter snakes on humans. (Behler and King, 2000; Conant and Collins, 1998; Holman et al., 1999)

Butler's garter snakes occupy an important ecological niche within their geographic range. They help control the population of earthworms, leeches, and slugs which often makes them a friend to gardeners. (Behler and King, 2000; Conant and Collins, 1998; Environment Canada, 2002; Holman et al., 1999; Toronto Zoo, 2002)

Butler's garter snakes are much less common than their larger relatives, common garter snakes. They are easily disturbed by habitat destruction and other human modifications of their habitats. The wet meadow habitats that they prefer have been largely eliminated and are still being developed at a rapid pace. Large colonies may survive in small pockets of habitat, even in abandoned urban lots, but these colonies can be eliminated in one afternoon when the land is bulldozed. They are listed as endangered in Indiana. (Behler and King, 2000; Conant and Collins, 1998; Environment Canada, 2002; Holman et al., 1999; Toronto Zoo, 2002)

Butler's garter snakes were named after early Indiana naturalist Amos Butler. The scientific name comes from Greek 'thamn', meaning shrub or bush, and 'ophis,' meaning snake. (Conant and Collins, 1998; Holman et al., 1999)