Animal Diversity Web

Ge­o­graphic Range

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)

• Biogeographic Regions
• nearctic

Habi­tat

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; "Adopt-A-Pond", 2002)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• scrub forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Wetlands
• marsh
• swamp

• Other Habitat Features
• urban
• suburban
• agricultural
• riparian

Phys­i­cal De­scrip­tion

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; "Adopt-A-Pond", 2002)

• Other Physical Features
• heterothermic

• Sexual Dimorphism
• female larger
• sexes shaped differently

• Range length

  38 to 73.7 cm

  14.96 to 29.02 in

• Average length

  45 cm

  17.72 in

Re­pro­duc­tion

But­ler's garter snakes breed each year as they emerge from win­ter hi­ber­na­tion sites. Ris­ing air tem­per­a­tures prompt males to begin court­ing fe­males. Fe­male But­ler's garter snakes are ca­pa­ble of stor­ing sperm from pre­vi­ous mat­ings (per­haps oc­cur­ring in the fall) and using that sperm in the spring. (Hard­ing, 1997; Hol­man, et al., 1999)

• Mating System
• polygynandrous (promiscuous)

But­ler's garter snakes are ovo­vi­vip­a­rous. Eggs are fer­til­ized within the fe­male's body and de­velop and hatch within her.

But­ler's garter snakes mate at their hi­ber­na­tion sites in the spring, be­fore they leave for their sum­mer feed­ing areas. Fe­males give birth in mid to late sum­mer to from 4 to 20 live young. Larger fe­males and those that are bet­ter nour­ished pro­duce more young per lit­ter. The young snakes grow rapidly and may be­come ma­ture in their sec­ond or third spring. They con­tinue to grow through­out their lives. (Behler and King, 2000; Co­nant and Collins, 1998; En­vi­ron­ment Canada, 2002; Hol­man, et al., 1999; "Adopt-A-Pond", 2002)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• sexual
• ovoviviparous
• sperm-storing

• Breeding interval

  Butler's garter snakes breed once yearly.

• Breeding season

  Butler's garter snakes breed in the spring (March to April).

• Range number of offspring

  4 to 20

• Average number of offspring

  12

  AnAge

• Average age at sexual or reproductive maturity (female)

  2-3 years

• Average age at sexual or reproductive maturity (female)
  Sex: female

  730 days

  AnAge

• Average age at sexual or reproductive maturity (male)

  2-3 years

Fe­male But­ler's garter snakes nur­ture their young in­side their bod­ies until they are born. Once the young are born there is no fur­ther parental care. (Behler and King, 2000; Co­nant and Collins, 1998; Hol­man, et al., 1999)

• Parental Investment
• no parental involvement
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

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)

• Range lifespan
  Status: captivity

  14 (high) years

• Typical lifespan
  Status: captivity

  6 to 10 years

Be­hav­ior

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. ("Stim­u­lus Con­trol of An­tipreda­tor Be­hav­ior in New­born and Ju­ve­nile Garter Snakes", 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)

• Key Behaviors
• terricolous
• natatorial
• diurnal
• nocturnal
• crepuscular
• sedentary
• hibernation
• solitary

• Range territory size

  30 to 270 m^2

Com­mu­ni­ca­tion and Per­cep­tion

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; "Adopt-A-Pond", 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.

• Communication Channels
• tactile
• chemical

• Other Communication Modes
• pheromones
• scent marks

• Perception Channels
• visual
• infrared/heat
• tactile
• acoustic
• vibrations
• chemical

Food Habits

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)

• Primary Diet
• carnivore
  • vermivore

• Animal Foods
• amphibians
• fish
• mollusks
• terrestrial worms

Pre­da­tion

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)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • milk snakes (Lampropeltis triangulum)
  • American crows (Corvus brachyrhynchos)
  • hawks (Accipitridae)
  • owls (Strigiformes)
  • raccoons (Procyon lotor)
  • striped skunks (Mephitis mephits)
  • weasels (Mustela)
  • shrews (Soricidae)
  • red foxes (Vulpes vulpes)
  • domestic cats (Felis silvestris)

Ecosys­tem Roles

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)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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; "Adopt-A-Pond", 2002)

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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)

Con­ser­va­tion Sta­tus

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; "Adopt-A-Pond", 2002)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

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)

Con­trib­u­tors

Tanya Dewey (au­thor), An­i­mal Di­ver­sity Web.

Jen­nifer Loup (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Toronto Zoo. 2002. "Adopt-A-Pond" (On-line ). Toronto Zoo. Ac­cessed 03/21/02 at www.​torontozoo.​com/​adoptapond/​guide/​butlergartersnake.​html.

The Cen­ter for Rep­tile Con­ser­va­tion and Man­age­ment. "But­ler's Garter Snake: Thamnophis but­leri" (On-line ). In­di­ana Uni­ver­sity Pur­due Uni­ver­sity Fort Wayne. Ac­cessed 03/21/02 at herpcenter.​ipfw.​edu/​outreach/​accounts/​reptiles/​snakes/​Butlers_​Garter_​Snake.​htm.

Amer­i­can Psy­cho­log­i­cal As­so­ci­a­tion. 1989. Stim­u­lus Con­trol of An­tipreda­tor Be­hav­ior in New­born and Ju­ve­nile Garter Snakes. Jour­nal of Com­par­a­tive Psy­chol­ogy, 103/3: 233-242.

Behler, J., F. King. 2000. Na­tional Audubon So­ci­ety: Field Guide to Rep­tiles and Am­phib­ians. New York: Al­fred A. Knopf Inc..

Brattstrom, B. 1965. Body Tem­per­a­tures of Rep­tiles. Amer­i­can Mid­land Nat­u­ral­ist, 73/2: 376-422.

Car­pen­ter, C, 1951. Com­par­a­tive Ecol­ogy of the Com­mon Garter Snake (Thamnophis s. sir­talis), the Rib­bon Snake (Thamnophis s. sauri­tus), and But­ler's Garter Snake (Thamnophis but­leri) in Mixed Pop­u­la­tions. Dis­ser­ta­tion..

Car­pen­ter, C, 1953. A Study of Hi­ber­nac­ula and Hi­ber­nat­ing As­so­ci­a­tions of Snakes and Am­phib­ians in Michi­gan. Ecol­ogy, 34/1: 74-80.

Car­pen­ter, C, 1956. Body Tem­per­a­ture of Three Species of Thamnophis. Ecol­ogy, 37/4: 732-735.

Co­nant, R., J. Collins. 1998. Rep­tiles and Am­phib­ians: East­ern/Cen­tral North Amer­ica. New York: Houghton Mif­flin Com­pany.

En­vi­ron­ment Canada, 2002. "Species at Risk: But­ler's Garter­snake" (On-line). En­vi­ron­ment Canada. Ac­cessed March 21, 2002 at http://​www.​speciesatrisk.​gc.​ca/​species/​search/​SearchDetail_​e.​cfm?​SpeciesID=588#​note.

Gould, F. An In­tro­duc­tion to the Nat­ural His­tory of North Amer­i­can Garter Snakes with Basic Triage Prac­tices.. Jour­nal of Wildlife Re­ha­bil­i­ta­tion, Vol. 21 (3-4). Ac­cessed 03/15/02 at http://​www.​thamnophis.​com.

Hard­ing, J. 1997. Am­phib­ians and Rep­tiles of the Great Lakes Re­gion. Ann Arbor, Michi­gan: The Uni­ver­sity of Michi­gan Press.

Hol­man, J., J. Hard­ing, M. Hens­ley, G. Dud­derar. 1999. Michi­gan Snakes. East Lans­ing, MI: Michi­gan State Uni­ver­sity Ex­ten­sion/MSU Mu­seum.

Jayne, B, , Ben­net, A. 1990. Se­lec­tion of Lo­co­mo­tor Per­for­mance Ca­pac­ity in a Nat­ural Pop­u­la­tion of Garter Snakes. Evo­lu­tion, 44/5: 1204-1229.

Shine, Richard, 1991. In­ter­sex­ual Di­etary Di­ver­gence and the Evo­lu­tion of Sex­ual Di­mor­phism in Snakes. Amer­i­can Nat­u­ral­ist, 138/1: 103-122.