Animal Diversity Web

Ge­o­graphic Range

West­ern rat snakes (Pan­therophis ob­so­le­tus) are a wide-rang­ing Nearc­tic non-ven­omous species. Their na­tive dis­tri­b­u­tion ex­tends through­out the cen­tral re­gion of the United States, as far north as the south­ern ex­tent of Min­nesota, south­ward along the Mis­sis­sippi River to the Gulf Coast. Their range en­com­passes south­east­ern Iowa, Mis­souri, Arkansas, and the ex­tent of Louisiana west of the Mis­sis­sippi River. West­ern rat snakes are found as far west as the south­ern ex­tent of Ne­braska and east­ern halves of Kansas, Ok­la­homa, and Texas. (Bur­brink, 2001; Fitch, 1963)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

West­ern rat snakes in­habit a va­ri­ety of habi­tats in the cen­tral United States. They can be found on rocky hill­sides and canyons, scrub/shrub fields, and prairie farm­lands. They can also be found in tem­per­ate de­cid­u­ous forests, swamps, wood­land edges, and grass­lands. West­ern rat snakes also in­habit dry or bar­ren wood­lands and sandy prairies. They also use rural an­thro­pogenic habi­tats such as aban­doned farm­lands, homes, old oil fields, and caves. Due to their large ge­o­graphic range, no exact el­e­va­tional range has been des­ig­nated. (Bur­brink, 2001; Fitch, 1963; Gib­bons and Dor­cas, 2015)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• forest
• scrub forest

• Wetlands
• marsh
• swamp

• Other Habitat Features
• agricultural
• caves

Phys­i­cal De­scrip­tion

West­ern rat snakes have rounded heads with no dis­tinct snout. Their ven­tral scales are a creamy white color and their dor­sal scales are a glossy black color, often with speck­les of brown, or­ange, or yel­low. West­ern rat snakes have weakly keeled scales that are oth­er­wise smooth, sim­i­lar to east­ern rat snakes (Pan­therophis al­leghanien­sis).

West­ern rat snakes pos­sess slen­der bod­ies and adults have a snout-vent length (SVL) be­tween 96 cm and 154 cm. At ma­tu­rity, males are typ­i­cally larger than fe­males; Adult males range in SVL from 108 to 154 cm and adult fe­males range in SVL from 96 to 120 cm. Adult males weigh 800 to 1,000 g, while adult fe­males weigh 600 to 700 g.

West­ern rat snake hatch­lings range in SVL from 29 cm to 37 cm and their weight ranges from 12 to 14 g. As ju­ve­niles, west­ern rat snakes often ex­hibit a more gray­ish color with tan blotches; their scales darken as they ma­ture. Ju­ve­niles also pos­sess smooth, weakly-keeled scales.

West­ern rat snakes have dis­tinct checker­board pat­terns on their bod­ies that dif­fer­en­ti­ate them other rat snake species in the genus Pan­therophis. They are also longer than other rat snakes, and are one the longest snake species in North Amer­ica. (Fitch, 1963; Gib­bons and Dor­cas, 2015; Linzey and Clif­ford, 1981; Mitchell, 1994)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger

• Range mass

  600 to 1000 g

  21.15 to 35.24 oz

• Range length

  96 to 154 cm

  37.80 to 60.63 in

De­vel­op­ment

West­ern rat snakes are oviparous, and eggs in­cu­bate for 65 to 70 days be­fore hatch­ing. Most early de­vel­op­ment oc­curs within the egg, with yolk pro­vid­ing en­ergy to de­vel­op­ing em­bryos. After hatch­ing, ju­ve­nile males mea­sure around 36.8 cm and ju­ve­nile fe­males mea­sure around 29 cm. Hatch­lings weigh ap­prox­i­mately 14 g and 12 g for males and fe­males, re­spec­tively.

West­ern rat snakes ex­hibit in­de­ter­mi­nate growth, but grow most rapidly as ju­ve­niles, within the first 3 to 7 years after hatch­ing. As ju­ve­niles, both sexes grow at a rate of 3.5 cm per month. How­ever, this rate is slowed dur­ing colder months, when west­ern rat snakes enter bru­ma­tion. After west­ern rat snakes reach sex­ual ma­tu­rity, growth rates are re­duced to ap­prox­i­mately 2 cm per year, al­though males grow faster than fe­males. West­ern rat snakes reach sex­ual ma­tu­rity be­tween 3 and 7 years old, but are con­sid­ered sex­u­ally ma­ture once they reach a cer­tain snout-vent length (SVL). Males are con­sid­ered ma­ture at a SVL of 107 cm, and fe­males are con­sid­ered ma­ture at a SVL of 96 cm. The max­i­mum recorded lengths for west­ern rat snakes were 154 cm for a male and 120 cm for a fe­male. (Fitch, 1963; Gib­bons and Dor­cas, 2015; Zug, et al., 2001)

• Development - Life Cycle
• indeterminate growth

Re­pro­duc­tion

Males and fe­males reach sex­ual ma­tu­rity be­tween 3 and 7 years old. They are polyg­y­nan­drous, mean­ing both males ad fe­males have mul­ti­ple mates. At the be­gin­ning of the breed­ing sea­son, adult males com­pete for the right to mate with fe­males.

West­ern rat snakes have a com­plex courtship pat­tern, in­volv­ing tac­tile and vi­sual rit­u­als. The process be­gins when an in­di­vid­ual male ap­proaches a fe­male and the two touch snouts. In some cases, the fe­male flees from the court­ing male, in which case the male pur­sues the fe­male until the fe­male stops and in­di­cates its re­cep­tiv­ity. The male then places its head atop the dor­sal side of the fe­male. The male main­tains chin con­tact with the dor­sal side of the fe­male, then mounts the fe­male by mov­ing the rest of its body onto the dor­sal side of the fe­male. The court­ing male then shakes the trunk of its body, slid­ing and twist­ing to keep the fe­male close. The male makes for­ward jerk­ing move­ments to­wards the head of the fe­male. The male also con­tracts its body in a spe­cific pat­tern, cre­at­ing cau­do­cephalic waves that in­duces greater re­cep­tiv­ity to in­sem­i­na­tion. Fi­nally, the male wraps the end of its tail around the pos­te­rior por­tion of the fe­male and in­serts its hemipe­nis into the cloaca of the fe­male. The mat­ing male may bite the neck of the fe­male to en­sure suc­cess­ful in­sem­i­na­tion be­fore the fe­male leaves. After mat­ing is com­plete, the male dis­mounts the fe­male and as­sumes a coiled po­si­tion. (Fitch, 1963; Gib­bons and Dor­cas, 2015; Gilling­ham, 1979)

• Mating System
• polygynandrous (promiscuous)

West­ern rat snakes emerge from bru­ma­tion around Feb­ru­ary, and their breed­ing sea­son spans from April to June. If tem­per­a­tures are warm enough in early fall, breed­ing sea­son may ex­tend later than June.

Fe­male west­ern rat snakes usu­ally lay mul­ti­ple clutches of egs dur­ing the mat­ing sea­son, with an av­er­age clutch size of 15 (range: 4 to 44 eggs). Ges­ta­tion pe­ri­ods have not been re­ported for west­ern rat snakes. The in­cu­ba­tion pe­riod for eggs is around 65 to 70 days. Im­me­di­ately after hatch­ing, male ju­ve­niles weigh about 14 g and mea­sure about 36.8 cm, while fe­male ju­ve­niles weigh about 12 g and mea­sure about 29.0 cm. Hatch­lings are in­de­pen­dent at birth. Male and fe­male west­ern rat snakes both reach sex­ual ma­tu­rity be­tween 3 and 7 years old. (Fitch, 1963; Gib­bons and Dor­cas, 2015; Gilling­ham, 1979; Zug, et al., 2001)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• oviparous

• Breeding interval

  Western rat snakes breed multiple times per year, from late spring through the summer.

• Breeding season

  April to June

• Range number of offspring

  4 to 44

• Average number of offspring

  15

• Range age at sexual or reproductive maturity (female)

  3 to 7 years

• Range age at sexual or reproductive maturity (male)

  3 to 7 years

Male west­ern rat snakes pro­vide no parental care be­yond the act of mat­ing. Fe­males build a nest for their eggs, but pro­vide no parental in­vest­ment be­yond this. West­ern rat snakes are im­me­di­ately in­de­pen­dent upon hatch­ing. (Fitch, 1963)

• Parental Investment
• precocial
• pre-hatching/birth
  • provisioning
    • female

Lifes­pan/Longevity

West­ern rat snakes raised in cap­tiv­ity are re­ported to live be­tween 16 and 33.9 years. The lifes­pan of west­ern rat snakes in the wild is not well doc­u­mented. How­ever, other mem­bers of the genus such as corn snakes (Pan­therophis gut­ta­tus) have been re­ported to live up to 24 years in the wild. (Perkins, 1955; Slavens and Slavens, 2003)

• Typical lifespan
  Status: captivity

  16 to 33.9 years

Be­hav­ior

West­ern rat snakes are soli­tary and will usu­ally avoid con­fronta­tion if pos­si­ble. If threat­ened, they ei­ther re­main mo­tion­less or at­tempt to flee the sit­u­a­tion. If cor­nered they coil their bod­ies and open their mouths to ap­pear threat­en­ing. They may also rapidly vi­brate their tails against nearby grass or leaves, which cre­ates a rat­tling sound sim­i­lar to that of a rat­tlesnake. If preda­tors are not de­terred by these threat dis­plays, west­ern rat snakes will strike and con­strict around preda­tors and emit a foul odor from their anal glands.

West­ern rat snakes com­mu­ni­cate in part using pheromones. Males es­tab­lish ter­ri­to­ries by se­cret­ing pheromones and fe­males use pheromones to at­tract po­ten­tial mates. West­ern rat snakes tend to be di­ur­nal, es­pe­cially dur­ing cooler spring months, but they be­come more ac­tive at night dur­ing the sum­mer.

West­ern rat snakes are par­tially ar­bo­real and are adept at climb­ing trees to prey upon birds or mam­mals nest­ing in tree hol­lows. West­ern rat snakes are also ca­pa­ble of swim­ming to reach prey or tra­verse their en­vi­ron­ment.

West­ern rat snakes seek shel­ter and bru­mate from Oc­to­ber to Feb­ru­ary, using hol­low trees, un­der­ground bur­rows, caves, tree stumps, or aban­doned houses. They emerge from bru­ma­tion around Feb­ru­ary, be­fore breed­ing sea­son be­gins. West­ern rat snakes do not travel far from where they bru­mate and nest, but rather in­habit one area con­sis­tently. (Durner and Gates, 1993; Fitch, 1963; Gib­bons and Dor­cas, 2015; Zug, et al., 2001)

• Key Behaviors
• arboreal
• scansorial
• terricolous
• troglophilic
• diurnal
• nocturnal
• motile
• sedentary
• hibernation
• solitary

Home Range

West­ern rat snakes have an av­er­age home range of 117 square me­ters, cen­tered around where they hi­ber­nate and nest. They will not ac­tively de­fend their home ranges against other west­ern rat snakes, al­though they es­tab­lish ter­ri­to­ries using pheromone mark­ings. (Durner and Gates, 1993; Fitch, 1963)

Com­mu­ni­ca­tion and Per­cep­tion

West­ern rat snakes com­mu­ni­cate chem­i­cally through pheromones and other gland se­cre­tions, which have an array of uses in­clud­ing de­fense from preda­tors and mate at­trac­tion. West­ern rat snakes usu­ally se­crete a de­fense pheromone in their dens and bur­rows which re­pels preda­tors. West­ern rat snakes also use pheromones to cre­ate trails for other west­ern rat snakes to fol­low to­wards high ag­gre­ga­tion sites such bru­ma­tion dens. Fe­male west­ern rat snakes pro­duce pheromones to at­tract males. These spe­cial­ized pheromones are unique to their species and are only rec­og­nized by other west­ern rat snakes.

Male west­ern rat snakes es­tab­lish dom­i­nance through touch. When male rat snakes de­tect a pheromone trail from com­pet­ing males, they will fol­low the trail to its source. Once they find each other, com­pet­ing males glide par­al­lel to each other with their heads raised high. This con­tin­ues until one of the males pushes its head down onto the other, as­sert­ing its dom­i­nance. Male west­ern rat snakes also use tac­tile senses to ini­ti­ate the mat­ing process with fe­males. Males also bite fe­males dur­ing the act of mat­ing.

West­ern rat snakes lack ex­ter­nal ears, but are ca­pa­ble of de­tect­ing high- and low-fre­quency seis­mic vi­bra­tions using their op­er­cu­laris sys­tems, or in­ter­nal ears. Their op­er­cu­laris sys­tems also help de­tect the move­ments of prey and preda­tors in their en­vi­ron­ment.

The eye­sight of west­ern rat snakes is lim­ited and they are only able to see a lim­ited array of col­ors. How­ever, they are highly sen­si­tive to UV light which has al­lowed them to adapt to low-light en­vi­ron­ments.

West­ern rat snakes rely heav­ily on smell to sense their en­vi­ron­ment. They flick their forked tongues out of their mouths to col­lect scent par­ti­cles from the ground and air. They then with­draw their tongues and in­sert the forked por­tions into two open­ings on the roofs of their mouths. These open­ings lead to their Jac­bo­son's organ, which they use to de­tect the di­rec­tion of scents emit­ted by prey, preda­tors, or other west­ern rat snakes. (Burns and Pen­ning, 2021; Gilling­ham, 1979; Gilling­ham, 1980; Zug, et al., 2001)

• Communication Channels
• visual
• tactile
• chemical

• Other Communication Modes
• pheromones
• scent marks
• vibrations

• Perception Channels
• visual
• ultraviolet
• tactile
• vibrations
• chemical

Food Habits

Adult west­ern rat snakes feed upon mam­mals in­clud­ing prairie voles (Mi­cro­tus ochro­gaster), pine voles (Mi­cro­tus pine­to­rum), west­ern har­vest mice (Re­i­throdon­to­mys mega­lo­tis), white-footed mice (Per­omyscus leu­co­pus), house mice (Mus mus­cu­lus), east­ern cot­ton­tails (Sylvi­la­gus flori­danus), hispid cot­ton rats (Sig­modon hispidus), east­ern woodrats (Neotoma flori­dana), and north­ern short-tailed shrews (Bla­r­ina bre­vi­cauda). They feed on var­i­ous avian species and their eggs, in­clud­ing fledg­ing blue jays (Cyanocitta cristata), mourn­ing doves (Zenaida macroura), and east­ern blue­birds (Sialia sialis). West­ern rat snakes also con­sume lizards such as com­mon five-lined skinks (Plestiodon fas­cia­tus) and other snakes (both con­specifics or other species). They also con­sume var­i­ous species of am­phib­ians (class Am­phibia) in­clud­ing frogs, toads, and sala­man­ders. A 1963 study on the diets of west­ern rat snakes sur­veyed 45 in­di­vid­u­als and found that 66% of their diet was mam­mals, 23% birds, 8% am­phib­ians, and 3% rep­tiles. (Bur­brink, 2001; Fitch, 1963; Weath­er­head, et al., 2003)

• Primary Diet
• carnivore
  • eats terrestrial vertebrates
  • eats eggs

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• eggs

Pre­da­tion

Known preda­tors of West­ern rat snakes in­clude red-tailed hawks (Buteo ja­maicen­sis), broad-winged hawks (Buteo platypterus), and east­ern screech owls (Megas­cops asio). Other snake species also prey on west­ern rat snakes, in­clud­ing cop­per­heads (Agk­istrodon con­tor­trix), speck­led kingsnakes (Lam­pro­peltis hol­brooki), east­ern rac­ers (Col­u­ber con­stric­tor), and Texas in­digo snakes (Dry­mar­chon mela­nu­rus ereben­nus). Mam­malian preda­tors in­clude rac­coons (Pro­cyon lotor), long-tailed weasels (Mustela fre­nata), and coy­otes (Canis la­trans).

West­ern rat snakes have de­vel­oped de­fense mech­a­nisms such as cryp­tic col­oration which helps them cam­ou­flage with their en­vi­ron­ment. A pri­mary de­fense used by west­ern rat snakes is kink­ing, where they ap­pear mo­tion­less and bend their bod­ies at dif­fer­ent an­gles. This kink­ing is a form of cam­ou­flage. When cor­nered, west­ern rat snakes coil up, with their mouths open, and vi­brate their tails against dry leaves or grass to cre­ate a rat­tling sound. If this does not work and they are di­rectly at­tacked, west­ern rat snakes con­strict around preda­tors and exude a foul odor from their anal glands. (De­Gre­go­rio, et al., 2015; Fitch, 1963; Gib­bons and Dor­cas, 2015)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Red-tailed hawk (Buteo jamaicensis)
  • Broad-winged hawk (Buteo platypterus)
  • Eastern screech owl (Megascops asio)
  • Copperhead (Agkistrodon contortix)
  • Speckled kingsnake (Lampropeltis holbrooki)
  • Eastern racer (Coluber constrictor)
  • Texas indigo snake (Drymarchon melanurus erebennus)
  • Raccoon (Procyon lotor)
  • Long-tailed weasel (Mustela frenata)
  • Coyote (Canis latrans)

Ecosys­tem Roles

West­ern rat snakes are pri­mary and sec­ondary preda­tors in their ecosys­tems. They con­trol pop­u­la­tions of com­mon mam­mal pests and nest­ing birds, in­clud­ing hispid cot­ton rats (Sig­modon hispidus), west­ern har­vest mice (Re­i­throdon­to­mys mega­lo­tis), prairie voles (Mi­cro­tus ochro­gaster), blue jays (Cyanocitta cristata), mourn­ing doves (Zenaida macroura), and east­ern blue­birds (Sialia sialis). West­ern rat snakes serve as a food source for mam­mals such as racoons (Pro­cyon lotor) and long-tailed weasels (Mustela fre­nata) and birds of prey such as red-tail hawks (Buteo ja­maicen­sis), broad-winged hawks (Buteo platypterus), and east­ern screech owls (Megas­cops asio).

West­ern rat snakes are hosts to par­a­sites such as har­vest mites (Trom­bic­ula al­fred­du­gesi) that cause red­dish en­crus­ta­tion be­tween their scales. West­ern rat snakes also host var­i­ous alve­o­late species, such as He­pa­to­zoon quadrivit­tata, He­pa­to­zoon spi­loides, He­pa­to­zoon hor­ridus, and He­pa­to­zoon sipedon, which are all ac­quired through mos­quito vec­tors. These par­a­sites re­duce the red blood cell counts and re­duce nu­tri­tional in­take of rat snakes, re­sult­ing in re­duced growth rates. Tape­worms such as Oo­cho­ris­tica eu­me­cis have been re­ported in the small in­testines of west­ern rat snakes, caus­ing in­flam­ma­tion and ab­nor­mal growth. Ad­di­tional tape­worms in­clude those in the genus Mesoces­toides. Api­com­plex­ans in the genus Sar­co­cys­tis also have been re­ported in Ok­la­homa, and coc­cid­i­ans in­clud­ing Eime­ria za­me­nis were found in Arkansas pop­u­la­tions. (Fitch, 1963; Lal­ley, 2004; McAl­lis­ter, et al., 2016; McAl­lis­ter, et al., 2014; McAl­lis­ter, et al., 2017; McAl­lis­ter, et al., 1993; Smith, 1996; Telford, et al., 2012)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

West­ern rat snakes are pop­u­lar in the pet trade, as they are con­sid­ered low-main­te­nance and suit­able for be­gin­ner snake own­ers. West­ern rat snakes are sold at prices rang­ing from 50 to 600 USD. (Ham­mer­son, 2019; Mor­phMar­ket, 2022)

• Positive Impacts
• pet trade

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

When threat­ened, west­ern rat snakes will in­flict a painful bite onto those it deems as a threat; the pain in­flicted de­pends upon the size of the snake. How­ever, west­ern rat snakes are non-ven­omous and will only bite as an act of self-de­fense against a sup­posed threat. Full treat­ment of wounds in­flicted by west­ern rat snakes at a hos­pi­tal will cost a per­son an es­ti­mated 2,058 USD on av­er­age due to lab costs and ex­penses. (Basher, et al., 2012; Burns and Pen­ning, 2021; Gilling­ham, 1980)

• Negative Impacts
• injures humans
  • bites or stings

Con­ser­va­tion Sta­tus

West­ern rat snakes are a species of "Least Con­cern" on the IUCN Red List. They do not have spe­cial sta­tus on the U.S. fed­eral list, CITES ap­pen­dices, or the state of Michi­gan list.

There are cur­rently no major threats to west­ern rat snakes. How­ever, some smaller pop­u­la­tions have de­clined due to ex­ten­sive de­for­esta­tion, which leads to habi­tat loss and prey de­ple­tion. Habi­tat de­struc­tion due to human en­croach­ment also makes west­ern rat snakes sus­cep­ti­ble to pop­u­la­tion losses. West­ern rat snakes are often mis­taken for rat­tlesnakes be­cause they vi­brate their tails when threat­ened, caus­ing peo­ple to mis­tak­enly kill them.

State man­age­ment agen­cies often com­plete sur­veys to iden­tify the home ranges of west­ern rat snakes to limit habi­tat de­struc­tion. There are ed­u­ca­tion pro­grams that in­form the pub­lic on the pos­i­tive im­pacts that west­ern rat snakes have on ecosys­tems. These im­pacts in­clude pop­u­la­tion con­trol of com­mon pest species that may af­fect farm­ers and home­own­ers.

West­ern rat snakes are a com­mon snake species in the cen­tral United States. They exist in al­ready-pro­tected areas, and are thus af­forded some basic lev­els of habi­tat pro­tec­tion. The pet trade should be reg­u­lated so that wild pop­u­la­tions re­main at healthy lev­els. (Bur­brink, 2001; Burns and Pen­ning, 2021; Gilling­ham, 1980; Ham­mer­son, 2019)

• 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

Con­trib­u­tors

Hunter Greer (au­thor), Rad­ford Uni­ver­sity, Sierra Felty (ed­i­tor), Rad­ford Uni­ver­sity, Bianca Plow­man (ed­i­tor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, Vic­to­ria Rauler­son (ed­i­tor), Rad­ford Uni­ver­sity, Christo­pher Woz­niak (ed­i­tor), Rad­ford Uni­ver­sity.

Ref­er­ences

Basher, A., A. Molla, N. Kakoly, A. Faiz. 2012. The im­pact of snake bite on house­hold econ­omy in Bangladesh. Trop­i­cal Doc­tor, 42/1: 43-1.

Blouin-De­mers, G., K. Prior, P. Weath­er­head. 2000. Pat­terns of vari­a­tion in spring emer­gence by black rat snakes (Elaphe ob­so­leta ob­so­leta). Her­peto­log­ica, 56/2: 175-188.

Bur­brink, F. 2001. Sys­tem­at­ics of the east­ern rat­snake com­plex (Elaphe ob­so­leta). Her­peto­log­i­cal Mono­graphs, 15: 1-53.

Burns, A., D. Pen­ning. 2021. Is there al­ways a need for speed? Test­ing for dif­fer­ences in the strik­ing be­hav­ior of west­ern rat­snakes (Pan­therophis ob­so­le­tus) when en­coun­ter­ing preda­tors and prey. Jour­nal of Her­petol­ogy, 55/1: 55-61.

Creque, T., J. Orr. 2012. An­nual and daily ac­tiv­ity cy­cles of snakes in north­ern Vir­ginia, USA. Her­peto­log­i­cal Bul­letin, 121: 23-28.

De­Gre­go­rio, B., J. Sperry, M. Ward, P. Weath­er­head. 2015. Wait until dark? Daily ac­tiv­ity pat­terns and nest pre­da­tion by snakes. Ethol­ogy, 121/12: 1225-1234.

De­Gre­go­rio, B., P. Weath­er­head, M. Ward, J. Sperry. 2016. Do sea­sonal pat­terns of rat snake (Pan­therophis ob­so­le­tus) and black racer (Col­u­ber con­stric­tor) ac­tiv­ity pre­dict avian nest pre­da­tion?. Ecol­ogy and Evo­lu­tion, 6/7: 2034-2043.

Durner, G., J. Gates. 1993. Spa­tial ecol­ogy of black rat snakes on Rem­ing­ton Farms, Mary­land. The Jour­nal of Wildlife Man­age­ment, 57/4: 812-826.

Fitch, H. 1963. Nat­ural his­tory of the black rat snake (Elaphe o. ob­so­leta) in Kansas. Copeia, 1963/4: 649-658.

Gib­bons, W., M. Dor­cas. 2015. Snakes of the South­east, Re­vised Edi­tion. Athens, GA: Uni­ver­sity of Geor­gia Press.

Gilling­ham, J. 1980. Com­mu­ni­ca­tion and com­bat be­hav­ior of the black rat snake (Elaphe ob­so­leta). Her­peto­log­ica, 36/2: 120-127.

Gilling­ham, J. 1979. Re­pro­duc­tive be­hav­ior of the rat snakes of east­ern North Amer­ica, genus Elaphe. Copeia, 1979/2: 319-331.

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