Diadophis punctatusarnyi

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Geographic Range

Ringneck snakes are common snakes occurring throughout eastern and central North America. Their range extends from Nova Scotia, southern Quebec, and Ontario to south-central Mexico, covering the entire eastern seaboard except for areas along the gulf coasts of south Texas and northeast Mexico. The range extends laterally to the Pacific coast except for large areas in drier regions of the western United States and Mexico. (Conant and Collins, 1998)

Habitat

Areas with abundant hiding places are preferred by all subspecies of D. punctatus but, beyond that, they occur in a wide variety of habitats. Gently moistened soil and 27 to 29 degrees Celsius provide optimal conditions. Northern and western subspecies prefer coverage under stones or under the loose bark of dead trees, and are often found in open woodlands near rocky hillsides. Southern subspecies tend to stay in conspicuously wet locales, such as swamps, damp forests, or riparian woodlands. (Ditmars, 1930; Dundee and Miller III, 1968)

Physical Description

The dorsum of ringneck snakes varies among subspecies from blue-gray to light brown to greenish-gray, but it is always solid, except for a distinctive golden ring around the neck. The ring may be interrupted or, in the cases of the regal ringneck snakes (D. punctatus regalis) and key ringneck snakes D. punctatus acricus, may appear only as a trace or be completely absent. The abdomen is orange-yellow, but western and extreme southern subspecies show a change in color to orange-red toward the posterior. The presence and configuration of black spots on the abdomen can be used to distinguish subspecies. (Conant and Collins, 1998)

Eastern subspecies have 15 scale rows at the anterior end; western subspecies have 17. Scales are smooth and the anal plate is divided. The species has a length of 25 to 38 cm, except D. punctatus regalis, which measures 38 to 46 cm. Newborn snakes have the same markings and coloration as adults. Generally speaking, adult females are longer than adult males. Molting occurs in all months of the year. (Blanchard, 1942; Conant and Collins, 1998; Myers, 1965)

  • Sexual Dimorphism
  • female larger
  • Range length
    25.5 to 46 cm
    10.04 to 18.11 in

Development

Female ringneck snakes reach an average of 20 cm in the first year, representing a 60% increase in length. In the second year they grow to about 24.5 cm and, in the third year, females tend to increase to approximately 29 cm. The fourth year they tend to reach about 34 cm, and in the fifth year they can be expected to reach 39 cm.

Males are slightly larger in the earlier stages of development, usually reaching 21.9 cm in the first year, 26 cm in the second, 28 cm in the third year, and about 31 cm in the fourth year. (Ernst and Ernst, 2003)

Reproduction

Pheromones released from the skin of a female ringneck snake attracts males during mating season. Rarely have ringneck snakes been observed mating, amounting to no more than 6 recorded sightings. While mating, males rub their closed mouths on their mate's body. They then bite the female around her neck ring, align their bodies with the female's, and release their sperm. (Ernst and Ernst, 2003)

Mating of ringneck snakes can occur in spring or fall--delayed fertilization is possible--and eggs are laid in June or early July. Females lay eggs each year, 3 to 10 eggs can be laid at one time, and are deposited together in covered, moist locations. In areas where colonies exist, it is not uncommon to find eggs laid in communal nests. A single egg is white with yellow ends and is elongated, approximating 1 inch in length. Juveniles hatch in August or September. (Aardema, et al., 2004; Blanchard, 1942; Jackson and Mirick, 2000; Myers, 1965)

Reproductive maturity of both sexes is reached at the age of three years, that is, by their fourth summer. Male ringneck snakes mature at a smaller size than females do. (Blanchard, 1942; Blanchard, et al., 1979)

  • Breeding interval
    Ringneck snakes breed once each year.
  • Breeding season
    Ringneck snakes breed in the spring or fall.
  • Range number of offspring
    3 to 10
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Ringneck snake eggs are not cared for, there is no parental investment after choosing a nest site and laying the eggs. This largely contributes to the high mortality rate of young ringneck snakes. (Dundee and Miller III, 1968; Scott, 1996)

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

The longest recorded lifespan in captivity is 6 years 2 months. In the wild, though, ringnecks have been recorded as having lived over 10 years. It is thought that they may have a lifespan approaching 20 years in the wild. (Blanchard, 1942; Blanchard, et al., 1979; Ernst and Ernst, 2003)

  • Range lifespan
    Status: wild
    20 (high) years
  • Average lifespan
    Status: wild
    10 years
  • Range lifespan
    Status: captivity
    6 (high) years

Behavior

Individuals can sometimes be found during daylight hours warming themselves under rocks directly exposed to the sun in open wooded areas. Ringneck snakes, however, are only active at night. In addition, ringneck snakes perennially return to single denning sites. (Conant and Collins, 1998; Dundee and Miller III, 1968)

This is a secretive, non-aggressive species that prowls nocturnally and rarely exposes itself to daylight. Despite their secretiveness, however, ringneck snakes are social animals and many populations exist as large colonies, numbering 100 individuals or more. Communities of six or more may be found sharing a single microhabitat. No information is known on the hierarchical structure of ringneck snake colonies. (Blanchard, 1942; Blanchard, et al., 1979; Dundee and Miller III, 1968)

Communication and Perception

Touching, rubbing, head nuzzling, and pheromones are all ways of communication for ringneck snakes. Males rub their heads on females during mating, and females release pheromones from their skin when trying to attract a mate. Ringneck snakes perceive the world around them via sight, smell, and touch. (Ernst and Ernst, 2003)

Food Habits

Prey of D. punctatus consists of small salamanders, lizards, and frogs, as well as earthworms and juvenile snakes of other species. Frequency of specific prey in the diet is dependent on availability. reports show that Michigan populations of eastern ringneck snakes (D. punctatus edwardsii) prey almost exclusively on red-backed salamanders. Ringneck snakes employ partial constriction to subdue their prey. (Blanchard, et al., 1979; Conant and Collins, 1998; Ditmars, 1930)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
    • vermivore
  • Animal Foods
  • amphibians
  • reptiles
  • mollusks
  • terrestrial worms

Predation

When ringneck snakes are alarmed, the tail is coiled and raised toward the intruder. This behavior occurs only in populations where the orange-red posterior is present. The red coloration may act as a warning signal. Western subspecies feign death on further provocation. When the snake is held, a musky saliva is secreted from the corners of its mouth, accompanied by a pungent, clinging odor. (Bustard, 1969; Conant and Collins, 1998)

Predators include coral snakes, kingsnakes, and racers. Other snakes sharing the geographical areas of the ringneck snake may also be predators. In addition, wild hogs, opossums, shrews, armadillos, skunks, screech owls, and bullfrogs are all suspected predators. Large spiders and centipedes have been observed feeding on juvenile ringneck snakes. (Dundee and Miller III, 1968; Myers, 1965)

Ecosystem Roles

Ringnecks may play a small role in biodegration by moving through surface debris such as branches and leaves within forests. They also take on the role of predator and prey within their habitat, helping to control pest populations and serving as sustenance for larger animals. (Blanchard, et al., 1979; Conant and Collins, 1998; Dundee and Miller III, 1968)

Economic Importance for Humans: Positive

Ringneck snakes are valued in the pet trade for their attractive coloration, and also play a part in research and education. Because they pose no real threat to humans, they are ideal for work with younger children in a school setting. Ringneck snakes also help in controling pest populations. (Conant and Collins, 1998; Dundee and Miller III, 1968)

  • Positive Impacts
  • pet trade
  • research and education
  • controls pest population

Economic Importance for Humans: Negative

Ringneck snakes do not adversely affect humans, though, at times, they may cause a slight inconvenience. Due to urbanization, it is not uncommon to find ringneck snakes in one's basement. In these circumstances ringnecks pose no real threat, and must simply be relocated. (Conant and Collins, 1998; Dundee and Miller III, 1968)

  • Negative Impacts
  • household pest

Conservation Status

Three subspecies are candidates for the federal endangered or threatened species lists. They are San Diego ringneck snakes (Diadophis punctatus similis), San Bernardino ringneck snakes (Diadophis punctatus modestus), and key ringneck snakes (Diadophis punctatus acricus). Key ringneck snakes are also a threatened species in the state of Florida and are protected under state law. The range of that subspecies is limited to a single island in the Florida Keys. In Idaho, regal ringneck snakes (Diadophis punctatus regalis), and northwestern ringneck snakes (Diadophis punctatus occidentalis), are considered species of special concern, and are protected under state law. (Scott, 1996)

Although ringneck snakes are rarely observed, they are fairly common throughout their range. They are secretive snakes and generally remain hidden. (Scott, 1996)

Other Comments

Ringnecks rarely bite but may release a foul smelling musk when handled. (Dundee and Miller III, 1968)

Contributors

Lauren Pajerski (editor), Undergraduate Research Opportunity Program, University of Michigan, Tanya Dewey (editor), Animal Diversity Web.

James Yung (author), Michigan State University, James Harding (editor), Michigan State 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

aposematic

having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.

biodegradation

helps break down and decompose dead plants and/or animals

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

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

delayed fertilization

a substantial delay (longer than the minimum time required for sperm to travel to the egg) takes place between copulation and fertilization, used to describe female sperm storage.

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.

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).

marsh

marshes are wetland areas often dominated by grasses and reeds.

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.

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

social

associates with others of its species; forms social groups.

solitary

lives alone

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.

visual

uses sight to communicate

References

Aardema, J., S. Beam, J. Boner, J. Bussone, C. Ewart. 2004. "Diadophis punctatus" (On-line). Amphibians and Reptiles of North Carolina. Accessed 04/12/04 at http://www.bio.davidson.edu/projects/herpcons/herps_of_NC/snakes/Dia_pun.html.

Blanchard, F. 1942. The ring-neck snakes, genus *Diadophis*. Bulletin of the Chicago Academy of Sciences, 7(1): 1-144.

Blanchard, F., M. Gilreath, F. Blanchard. 1979. The eastern ring-neck snake (*Diadophis punctatus edwardsii*) in northern Michigan. Journal of Herpetology, 13(4): 377-402.

Bustard, H. 1969. Behavior of the Pacific Boa. Herpetologica, 25: 164-170.

Conant, R., J. Collins. 1998. A field guide to reptiles & amphibians of eastern and central North America, 3rd ed., expanded. Boston: Houghton Mifflin Company.

Ditmars, R. 1930. Reptiles of the world. New York: The MacMillan Company.

Dundee, H., M. Miller III. 1968. Aggregative behavior and habitat conditioning by the prairie ringneck snake, *Diadophis punctatus arnyi*. Tulane Studies in Zoology and Botany, 15(2): 41-58.

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

Jackson, S., P. Mirick. 2000. "Ringneck Snake" (On-line). Snakes of Massachusetts. Accessed 04/12/04 at http://www.umass.edu/umext/nrec/snake_pit/pages/ringn.html.

Myers, C. 1965. Biology of the ringneck snake, *Diadophis punctatus*, in Florida. Bulletin of the Florida State Museum, Biological Sciences, 10(2): 43-90.

Scott, C. 1996. Snake Lovers' Lifelist & Journal. Austin: University of Texas Press.