Pituophis melanoleucusEastern Pine Snake

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Geographic Range

Pituophis melanoleucus can be found in the eastern half of the United States. There are 5 subspecies recognized, including northern pine snakes found in southern New Jersey, the coastal plains of North Carolina and South Carolina, the mountains of western Virginia and eastern West Virginia, Maryland, New York, southern Kentucky, Tennessee, Alabama and Georgia. Florida pine snakes are found in Florida, Alabama, Georgia, North Carolina, and southwestern South Carolina. Louisiana pine snakes are found in western Louisiana and eastern Texas. Black pine snakes are found in southwestern Alabama, southeastern Louisiana, and Mississippi. Finally, bullsnakes are found in western Indiana, Illinois, Wisconsin, southern Minnesota, parts of Canada and southwest to southern and western Texas and Mexico. (Ernst and Barbour, 1989; Ernst and Ernst, 2003; Wright and Wright, 1957)

Habitat

Pine snakes are found at elevations up to 152.4 meters above sea level in a variety of habitats, including pine barrens, mixed scrub pine and oak woods, dry rocky mountain ridges, sand hills, and old fields. In New Jersey, disturbed habitats are used as much as 90% of the time by pine snakes. Males are generally found near logs and bark, while females are more frequently found under oak leaves. (Ernst and Ernst, 2003)

  • Range elevation
    0 to 152.4 m
    0.00 to 500.00 ft

Physical Description

Pine snakes are the second-largest snake in northeastern North America, ranging in size from 91 to 254 cm in length and up to 5 cm in diameter. Pine snakes are powerful, nonvenomous constrictors. All members of the genus Pituophis have a cartilaginous keel in front of the glottis which amplifies hissing to mimic a rattlesnake. The head of the pine snake resembles that of a turtle, small in comparison to its body size, with a sharply pointed snout that protrudes over the lower jaw. Their skulls are different from those of western pine snakes, specifically in regard to nasal/premaxilla articulation, suggesting differences in digging behavior. The scales of pine snake are keeled in about 27 to 37 rows with a single anal plate. Unlike most other North American snakes, they have 4 instead of 2 prefrontal scales. Subspecies vary in appearance. Northern pine snakes are dull white to cream on the dorsum and intensely white on the sides with black body blotches anteriorly and brown blotches posteriorly. Bullsnakes range in color from yellow to tan with reddish-brown lateral spots. Florida pine snakes range in color from gray-brown to rusty-brown with faded, indistinct, blotched patterning. Black pine snakes are almost completely black or dark brown with a reddish snout. Juvenile pine snakes are dull in color and brighten after shedding their skin for the first time. Sexual dimorphism has not been reported in this species. (Cochran and Goin, 1970; Conant and Collins, 1991; Ditmars, 1931; Ditmars, 1939; Ernst and Barbour, 1989; Ernst and Ernst, 2003; Greene, 1997; Wright and Wright, 1957)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    91 to 254 cm
    35.83 to 100.00 in

Development

Pine snakes are oviparous and have an incubation period of about 51 to 100 days. Hatchlings range in length from 30 to 58 cm. It is not known if pine snakes grow throughout their entire lives or not. (Cochran and Goin, 1970; Ernst and Barbour, 1989; Ernst and Ernst, 2003; Greene, 1997; Wright and Wright, 1957)

Reproduction

Pine snakes breed annually. Although information on the mating system of this species is known for only portions of its geographic range, research has shown that Florida pine snakes are polygynous. The home range of several females often overlaps that of a single male. There have been no recorded studies about the mating systems of other subspecies of pine snake. Studies show that the testes of male pine snakes are regressed in April and May and begin to appear in June. They go through spermiogenesis in late summer/early autumn. The sperm then pass to the epididymis and vas deferens where it is stored until the spring breeding season. During breeding, the male crawls over the female, holds onto her by grasping her head or neck in his mouth, and mates with her. Breeding may last from half an hour to over an hour. (Ernst and Barbour, 1989; Ernst and Ernst, 2003; Greene, 1997; Seigel and Collins, 1993)

Female pine snakes have an annual breeding cycle which extends from April through May. Detailed information regarding pine snakes is restricted to specific subspecies. Florida pine snakes may mate during the winter due to warmer weather throughout the rest of the year. Gestation usually lasts 28 to 39 days. Pine snakes are oviparous and lay eggs from May through July in underground burrows, underneath rocks or logs. Although some pine snakes are solitary and stick to their own nests, others are communal and share nests with conspecifics. Clutch size ranges from 3 to 24 eggs with an average of 8, and incubation lasts about 51 to 100 days with an average of 73. Louisiana pine snakes generally lay fewer, larger eggs. Young emerge in August or September. Hatchlings range in length from 30 to 58 cm and range in mass from 23 to 60 grams. Hatchling sex ratios generally favor males while adult females outnumber adult males. Pine snakes reach sexual maturity about 3 years after hatching. Males-male combat is common during the breeding season. (Cochran and Goin, 1970; Conant and Collins, 1991; Ernst and Barbour, 1989; Ernst and Ernst, 2003; Greene, 1997; Wright and Wright, 1957)

  • Breeding interval
    Pine snakes breed once yearly.
  • Breeding season
    Pine snakes usually breed from April to May.
  • Range number of offspring
    3 to 24
  • Average number of offspring
    8
  • Range gestation period
    28 to 39 days
  • Average gestation period
    35 days
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    3 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

There is no information available regarding the average lifespan of wild pine snakes. In captivity, the oldest known pine snake lived to be 22 years, 5 months, and 1 day old. At the San Diego Zoo, a captive born female pine snake lived to be 20 years, 9 months, and 2 day old. One pine snake reportedly lived only 4 years, 6 months in captivity. (Ernst and Barbour, 1989; Ernst and Ernst, 2003; Wright and Wright, 1957)

  • Range lifespan
    Status: captivity
    4.5 to 22.5 years

Behavior

Pine snakes are generally diurnal, but a few subspecies may be active during the night. In general, they are active from late March or April until late October or early November. They hibernate in underground burrows during the winter months and sometimes aestivate during the summer. Some subspecies are known to bask in the morning sun in order to raise their body temperature. Pine snakes have a pointed snout and enlarged rostral scale which are designed for burrowing underground to escape uncomfortable temperatures or predators, to find prey, and to build their nests. Pine snakes are usually found on the ground, but may climb into low bushes or trees. Males of several subspecies are known to engage in combat during breeding season. When threatened, eastern pine snakes use a cartilaginous keel in front of the glottis to amplify a hissing sound and vibrates its tail to resemble a rattlesnake. When attaching, they use a sweeping strike to make appear more vicious. Eastern pine snakes can make a hissing sound or a bellow (i.e., a loud, deep sound like a bull) in order to intimidate potential predators. (Ditmars, 1931; Ditmars, 1939; Ernst and Barbour, 1989; Ernst and Ernst, 2003; Knight, 1986; Young, et al., 1995)

  • Range territory size
    0.11 to 0.92 km^2
  • Average territory size
    0.50 km^2

Home Range

Information regarding regarding home range in pine snakes is limited to certain subspecies. Studies show that the Florida pine snakes have an average home range of 0.50 km^2. Two radio tracked females had ranges of 0.11 km^2 and 0.12 km^2. Three radio tracked males had a range of approximately 0.23 to 0.92 km^2. Males have non-overlapping ranges while female home ranges frequently overlap. Several females occupy the home range of a single male, suggesting that pine snakes are polygynous. (Ernst and Ernst, 2003; Seigel and Collins, 1993)

Communication and Perception

Little information is known about communication and perception in Pituophis melanoleucus. Juveniles recognize conspecifics via olfaction. It is possible that adult males recognize females in a similar manner. (Ernst and Ernst, 2003)

Food Habits

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

Predation

Pine snakes are preyed upon by short-tailed shrews, raccoons, striped skunks, red foxes, domestic dogs and cats. Pine snake eggs are commonly eaten by scarlet snakes. When threatened, pine snakes make a hissing sound or a bellow (i.e., a loud, deep sound) to intimidate its predators and vibrates its tail to resemble a rattlesnake. They also use a sweeping strike in an effort to appear more vicious. Evidence suggests that hatchlings avoid scent trails made by potential predators and are able to avoid predators such as hawks and owls by finding cover under pine boughs and other debris. (Burger, et al., 1992; Ernst and Barbour, 1989; Ernst and Ernst, 2003; Greene, 1997)

  • Anti-predator Adaptations
  • mimic

Ecosystem Roles

Pine snakes are important predators of small mammals such as mice and rats, ground squirrels, and gophers, which are destructive agricultural pests. Parasites of this species are unknown. (Ditmars, 1939)

Economic Importance for Humans: Positive

Pine snakes prey on many species of rodents and may help control the abundance of agricultural pests throughout their geographic range. Hatchlings are sometimes captured and either sold or kept as pets. They are among the most popular snakes kept as pets. (Burger, et al., 1992; Ernst and Barbour, 1989; Greene, 1997)

  • Positive Impacts
  • pet trade
  • controls pest population

Economic Importance for Humans: Negative

When threatened, the pine snake can inflict a painful bite. Pine snakes are non-venomous and only bite in self-defense. There are no other known adverse effects of pine snakes on humans. (Ditmars, 1939; Ernst and Barbour, 1989)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

As a collective species, Pituophis melanoleucus is classified as "least concern" on the IUCN's Red List of Threatened Species. However, several subspecies are currently protected throughout parts of their geographic ranges. For example, black pine snakes are protected in Alabama and Mississippi. Common pine snakes are considered a species of special concern in North Carolina and are threatened in Kentucky, New Jersey and Tennessee. Florida pine snakes are protected in Alabama and South Carolina, and are a species of special concern in Florida. The single greatest threat to this species is habitat destruction; however, it occurs in protected habitat at various locations throughout its geographic range. (Ernst and Ernst, 2003)

Other Comments

Pituophis melanoleucus belongs to the family Colubridae, the largest family of snakes in the world. ("Snake", 1987)

Contributors

Lynn Rasmussen (author), Northern Michigan University, Mary Martin (editor), Northern Michigan University, John Berini (editor), Animal Diversity Web Staff, Catherine Kent (editor), Special Projects.

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

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

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

union of egg and spermatozoan

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

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.

hibernation

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.

mimicry

imitates a communication signal or appearance of another kind of organism

native range

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

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.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

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

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

1987. Snake. Pp. 436-438 in S-Sn, Vol. 17, 15 Edition. Chicago, London, Sydney, Toronto: World Book, Inc..

Burger, J. 2007. The behavioral response of emerging pine snakes (Pituophis melanoleucus) to people: implications for survival and protection. Urban Ecosystems, 10: 193-201.

Burger, J., R. Zappalorti, J. Dowdell, T. Georgiadis, J. Hill, M. Gochfeld. 1992. Subterranean Predation on Pine Snakes (Pituophis melanoleucus). Journal of Herpetology, 26: 259-263.

Cochran, D., C. Goin. 1970. The New Field Book of Reptiles and Amphibians. New York: G.P. Putnam's Sons.

Conant, R., J. Collins. 1991. A Field Guide to Reptiles and Amphibians - Eastern and Central North America. Boston: Houghton Mifflin Company.

Ditmars, R. 1939. A Field Book of North American Snakes. Garden City, NY: Doubleday & Company, Inc..

Ditmars, R. 1931. Snakes of the World. New York: The Macmillan Company.

Ernst, C., R. Barbour. 1989. Snakes of Eastern North America. Fairfax, VA: George Mason University Press.

Ernst, C., E. Ernst. 2003. Snakes of the United States and Canada. Washington and London: Smithsonian Institute.

Greene, H. 1997. Snakes: The Evolution of Mystery in Nature. Berkeley and Los Angeles, CA: University of California Press.

Knight, J. 1986. Variation in Snout Morphology in the North American Snake Pituophis melanoleucus (Serpentes: Colubridae). Journal of Herpetology, 20: 77-79.

Seigel, R., J. Collins. 1993. Snakes -Ecology and Behavior. New York: McGraw-Hill, Inc..

Wright, A., A. Wright. 1957. Handbook of Snakes. Ithaca, NY: Comstock Publishing Associates.

Young, B., S. Sheft, W. Yost. 1995. Sound Production in Pituophis melanoleucus (Serpentes: Colubridae) With the First Description of a Vocal Cord in Snakes. The Journal of Experimental Zoology, 273: 472-481.