Pituophis cateniferGopher Snake

Geographic Range

Pituophis catenifer is found from southwestern Canada south to northern New Mexico. Gopher snakes are found from south-central British Columbia and southern Alberta and Saskatchewan, through the central and western United States, and south through Baja California and Sinaloa, Durango, Zacatecas, and Tamaulipas states in Mexico. In the United States they are found from the Pacific coast eastwards to Wisconsin, Illinois, Missouri, Oklahoma, and western Texas. There are 11 subspecies recognized, with some of those proposed as valid species, including P. c. vertebralis, from southernmost Baja California. Several subspecies represent isolated, island forms, including Cedros Island gopher snakes (P. c. insulanus), San Martin Island gopher snakes (P. c. fuliginatus), Coronado Island gopher snakes (P. c. coronalis), and Santa Cruz gopher snakes (P. c. pumilis). (Rodríguez-Robles, 2003)

Habitat

Gopher snakes are found in a wide variety of habitats, including woodlands, deserts ,agricultural areas (such as cultivated fields), prairies, chaparral, and shrublands. Radiotelemetry studies have shown that, although they are often found near moist habitats, such as marshes and moist woodlands, they prefer to spend most of their time in open parts of those habitats, such as grassland and forest edges. This preference is likely related to foraging activities. (Rodríguez-Robles, 2003)

Physical Description

Gopher snakes range in body length from 180 to 275 cm. They have relatively large heads, narrow necks, and large eyes as compared to most species of similar body length. Gopher snakes are marked with brown to black blotches on a background color of lighter straw to gray. Color patterns vary regionally and often mimic the colors of the dominant cover vegetation in a region. Individuals that are blotched, striped, or even albino are known from wild populations. Their ventral surface is generally white to yellowish, sometimes with dark spots. They usually have a dark line across the face in front of the eyes and from behind the eyes to the angle of the jaw. Gopher snakes have keeled scales and a single anal scale. They have 27 to 37 scale rows at their midbody. Superficially, gopher snakes resemble many species of rattlesnakes and are often mistaken for them. Gopher snakes are not venomous and do not have rattles on the end of their tail. (Waye and Shewchuk, 2002)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    180 to 275 cm
    70.87 to 108.27 in

Development

Gopher snakes are oviparous and have an incubation period of about 65 to 75 days. When hatched the young measure 30 to 35 cm in length. After hatching, Pituophis catenifer exhibits indeterminate growth. In the first three years growth is rapid, then slows for the rest of their life. (Cowles, 1935; Waye and Shewchuk, 2002)

Reproduction

Males compete for access to reproductively receptive females. Receptive females emit skin secretions that males detect through chemosensation and stimulates mating behaviors. Males will attempt to mate with as many receptive females as they can find. Males and females don't generally associate before or after mating. (Waye and Shewchuk, 2002)

Gopher snakes breed once yearly, usually in June to August. Some females lay two clutches each year. They are oviparous and have an incubation period of 65 to 75 days. Once the 2 to 24 young hatch from the eggs, they are left to fend for themselves. It takes about 4 years for females to reach sexual maturity, but only 1.5 years for males. (Cowles, 1935; Waye and Shewchuk, 2002)

  • Breeding interval
    Gopher snakes usually breed once a year, although some females may have 2 clutches.
  • Breeding season
    Breeding usually occurs from June to August.
  • Range number of offspring
    2 to 24
  • Range gestation period
    65 to 75 days
  • Range age at sexual or reproductive maturity (female)
    3 to 5 years
  • Range age at sexual or reproductive maturity (male)
    1 to 2 years

Females lay their eggs in nests, which are sometimes communal. After the eggs are laid there is no further parental care.

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

Lifespan/Longevity

The average life span in wild gopher snakes is 12 to 15 years. In captivity they have been known to live for as long as 33 years. (Hiatt, 1998; Waye and Shewchuk, 2002)

  • Range lifespan
    Status: captivity
    33 (high) years
  • Typical lifespan
    Status: wild
    12 to 15 years

Behavior

Gopher snakes are solitary, except during the mating season. They live alone in dens or other areas that provide adequate shelter. Radiotelemetry studies have found that individuals spend up to 90% of their time in underground burrows. They can also swim and climb well. Gopher snakes are mainly diurnal, but are also active at night sometimes. Like other snakes, gopher snakes go through periods of dormancy when resting or during periods of little food. (Rodríguez-Robles, 2003)

  • Range territory size
    0.0089 to 0.0178 km^2

Home Range

Home range size of four radio-tracked male gopher snakes in California was 0.89 to 1.78 ha. However, they spend the majority of their time in a smaller 0.1 to 0.29 ha section of these home ranges. Individual home ranges rarely overlap with one another. These snakes show a great deal of site fidelity across years. Multi-year studies have found individuals were recaptured about 150 m from their point of release 6 years prior. (Rodríguez-Robles, 2003)

Communication and Perception

Because they are primarily solitary, there is little communication among Pituophis catenifer individuals. During mating season, females indicate they are ready to mate by releasing skin secretions. Gopher snakes use their tongues and vomeronasal organs to "smell" their surroundings. They also use vision, touch, and sensing vibrations to perceive their environment. (Waye and Shewchuk, 2002)

Food Habits

Gopher snakes use constriction to capture and kill their prey. Typical prey include small mammals, birds, lizards, smaller snakes, insects, and eggs. Prey varies regionally but the primary prey in all areas are rodents and other small mammals. In some areas they prey mainly on gophers (Geomyidae), which is why they are called "gopher snakes." Gopher snakes actively search for prey in their burrows and hiding places. They often follow small mammal runways, and are quite successful in capturing voles (Microtus), western harvest mice (Reithrodontomys megalotis), Peromyscus species, kangaroo rats (Dipodomys), ground squirrels (Spermophilus), and young rabbits (Sylvilagus). They have also been known to eat bats in roosts. Lizards and snakes taken include side-blotched lizards (Uta) and rattlesnakes (Crotalus). They take birds, eggs, and insects occasionally as well. (Rodríguez-Robles, 1998; Rodríguez-Robles, 2003; Waye and Shewchuk, 2002)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles
  • eggs
  • insects

Predation

Kit foxes Vulpes macrotis , red-tailed hawks Buteo jamaicensis, and coyotes Canis latrans are the most common predators of the gopher snake. They are probably also preyed on by other foxes (Vulpes vulpes and Urocyon cinereoargenteus), hawks (Accipitridae), and large king snakes (Lampropeltis). Gopher snakes are cryptically colored and remain hidden except when actively pursuing prey or basking in open areas. They are large snakes and can inflict a painful bite if harassed. They also behaviorally mimic rattlesnakes by coiling, raising their heads, and rapidly shaking their tails when threatened by a predator or unsuspecting human. Their rattlesnake mimicry can be very convincing and many gopher snakes are killed as rattlesnakes. Non-human predators are likely to be discouraged from attacking gopher snakes when they are mimicing rattlesnakes. (Hiatt, 1998; Waye and Shewchuk, 2002)

  • Anti-predator Adaptations
  • mimic
  • cryptic

Ecosystem Roles

Gopher snakes play an important role in the ecosystems in which they live. They are important predators of small mammals, many of which are considered pests by humans. Gopher snakes can greatly reduce the numbers of small mammals in an area.

Parasite surveys have discovered mites (Trombicula arenicola) on gopher snakes, as well as ticks, fleas, and chiggers. Internal parasites include a blood protozoan (Hepatozoon serpentium) and an intestinal parasite (Tritrichomonas batrachorum). (Allred and Beck, 1964; Hilman and Strandtmann, 1960; Honigberg, 1953; Waye and Shewchuk, 2002)

Commensal/Parasitic Species
  • mites (Trombicula arenicola)
  • blood protozoan (Hepatozoon serpentium)
  • intestinal parasite (Tritrichomonas batrachorum)

Economic Importance for Humans: Positive

Gopher snakes are important predators on crop pests and play a role in agricultural losses to rodents. They are also good pets if well cared for. Gopher snakes are sometimes killed because they are mistaken for rattlesnakes, which they superficially resemble, but gopher snakes are harmless and beneficial snakes. (Waye and Shewchuk, 2002)

  • Positive Impacts
  • pet trade
  • controls pest population

Economic Importance for Humans: Negative

When harassed, gopher snakes can inflict a painful bite, depending on their size. But these snakes are non-venomous and will only bite in self-defense. Gopher snakes are sometimes mistaken for rattlesnakes because of their size, coloration, and habit of wiggling their tail when they feel threatened. (Hiatt, 1998)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Pituophis catenifer is fairly stable throughout its range and is listed as a species of "Least Concern" on the IUCN list. Island populations may be especially susceptible to environmental changes or persecution.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Josh Albert (author), Radford University, Karen Francl (editor, instructor), Radford University.

Glossary

Nearctic

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

agricultural

living in landscapes dominated by human agriculture.

carnivore

an animal that mainly eats meat

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

cryptic

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.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
fertilization

union of egg and spermatozoan

forest

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

heterothermic

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.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.

island endemic

animals that live only on an island or set of islands.

iteroparous

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).

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

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

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

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

pheromones

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

polygynandrous

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

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

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

solitary

lives alone

suburban

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

tactile

uses touch to communicate

temperate

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).

terrestrial

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.

savanna

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.

vibrations

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

visual

uses sight to communicate

References

Allred, D., D. Beck. 1964. Mites on Reptiles at the Nevada Atomic Test Site. Transactions of the American Microscopical Society, 83/2: 266-268.

Cowles, R. 1935. Notes on the Life History of Pituophis catenifer deserticola (Stejneger) (in Herpetological Notes). Copeia,, Vol. 1935, No. 1: 44.

Hiatt, S. 1998. "The Pituophis Page" (On-line). Accessed November 08, 2007 at http://www.kingsnake.com/pituophis/care_group7.html.

Hilman, J., R. Strandtmann. 1960. The Incidence of Hepatozoon Serpentium in Some Texas Snakes. The Southwestern Naturalist, 5/4: 226-228.

Honigberg, B. 1953. Structure, Taxonomic Status, and Host List of Tritrichomonas batrachorum (Perty). The Journal of Parasitology, 39/2: 191-208.

Rodríguez-Robles, J. 1998. Alternative Perspectives on the Diet of Gopher Snakes (Pituophis catenifer, Colubridae): Literature Records versus Stomach Contents of Wild and Museum Specimens. Copeia, Vol. 1998, No. 2.: 463-466.

Rodríguez-Robles, J. 2003. Home Ranges of Gopher Snakes (Pituophis catenifer, Colubridae) in Central California (in Shorter Contributions). Copeia, Vol. 2003, No. 2: 391-396.

Waye, H., C. Shewchuk. 2002. COSEWIC Assessment and Status Report on the Gopher Snake Pituophis catenifer. Canada: Cosewic.