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(North American) Wood Turtle

Glyptemys insculpta

What do they look like?

Adult wood turtles have a shell length of 16 to 25 cm (6.3 to 9.8 inches). It is brownish to gray-brown in color.

The head of the adult turtle is black, occasionally with light dots or other markings; the scales on the upper legs are black to brown, while the skin on the throat, lower neck, and on the lower parts of the legs can be yellow, orange, or orange-red to salmon-red, sometimes speckled with darker colors.

Hatchling turtles have round shells that range in length from 2.8 to 3.8 cm (1.1 to 1.5 inches); their tails are nearly as long as the shell itself. At hatching they are a brown or gray color. (Conant and Collins, 1998; Ernst, et al., 1994)

Where do they live?

Glyptemys insculpta, the wood turtle, is found in a small area of eastern Canada and the northeastern United States, from Nova Scotia and New Brunswick south through New England, Pennsylvania and northern New Jersey, to northern Virginia, and west through southern Quebec, southern Ontario, northern Michigan (northern Lower and Upper Peninsulas), northern and central Wisconsin, to eastern Minnesota; these turtles can also be found in northeastern Iowa. In this range, wood turtles are uncommon. (Harding, 1997; Harding, 1997)

What kind of habitat do they need?

Glyptemys insculpta is found near moving water (streams, creeks, or rivers), although some turtles may wander considerable distances away from water, especially in the warmer months. Streams with sand or sand and gravel bottoms are preferred, but rocky stream courses are sometimes used. Wood turtles are often described as woodland turtles, but in reality, they can live comfortably in a number of habitats such as woods, shrub or berry thickets, swamps, and open, grassy areas. (Ernst, et al., 1994; Harding, 1997)

  • Aquatic Biomes
  • rivers and streams

How do they reproduce?

Older, larger males tend to be dominant over smaller male wood turtles, and also have better success in mating.

Courtship may include a mating "dance" in which the male and female face each other and swing their heads back and forth; more often the male simply chases the female while nipping at her limbs and shell and then mates with her in shallow water on a sloping stream bank. Mating is most frequent in spring and fall, when the turtles are more aquatic.

In May or June, female wood turtles search for open, sunny nesting sites, preferring sandy banks near moving water. The female digs the nest with her hind feet into which she lays 3 to 18 eggs (usually 5 to 13). The eggs are carefully buried, and the female camouflages the nest, then departs, offering no further protection to her offspring. Females may not reproduce every year (Harding, 1977, 1991, 1997).

Most wood turtle eggs never hatch; nest predation by raccoons, skunks, shrews, foxes, and other predators can typically result in high losses. Incubation requires from 47 to 69 days. Hatchling G. insculpta hatch from their nests in late August or September and move to water.

Wood turtles in the wild usually reach adulthood between 14 and 20 years of age.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    5840 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    5840 days
    AnAge

How long do they live?

Wood turtles can live up to 58 years and possibly longer.

How do they behave?

Wood turtles are diurnal animals and spend much of their active time taking up sunlight during the day.

Glyptemys insculpta hibernate in winter (October through April in northern Michigan), generally on the bottom in the shallows of streams and rivers where the water will not freeze.

Individual wood turtles tend to remain within a home range of about 1 to 6 hectares (2.5 to 15 acres). Most turtles remain in or within a short distance of moving water throughout the year.

These turtles are quite agile and are unusually intelligent (for turtles).

What do they eat?

Glyptemys insculpta is an omnivorous turtle that can feed both in and out of water. Natural foods for the species include leaves and flowers of various woody plants (violet, strawberry, raspberry, willow), fruits (berries), fungi, slugs, snails, worms, and insects. They will occasionally eat young mice or eggs, or scavenge dead animals.

Wood Turtles in some areas are known to capture earthworms by thumping the ground with their feet or the front of the shell. It is thought that the worms mistake the vibrations caused by this thumping for the approach of a mole, and come to the surface, only to be grabbed by the hungry turtle. (Conant and Collins, 1998; Ernst, et al., 1994; Harding, 1991; Harding, 1997)

  • Animal Foods
  • eggs
  • carrion
  • insects
  • terrestrial non-insect arthropods
  • mollusks
  • terrestrial worms
  • aquatic crustaceans
  • Plant Foods
  • leaves
  • roots and tubers
  • fruit
  • flowers
  • Other Foods
  • fungus

Do they cause problems?

This species of turtle is harmless to humans.

How do they interact with us?

Wood Turtles were once hunted for human food (in the east) and for the biological supply trade , and in the last few decades they have been collected for the pet trade. Most populations of G. insculpta are now greatly reduced from former numbers, and many have become locally extinct (Harding, 1991, 1997). (Harding, 1991; Harding, 1997)

  • Ways that people benefit from these animals:
  • pet trade
  • food
  • body parts are source of valuable material
  • research and education

Are they endangered?

Because G. insculpta gives birth to few young in its lifetime, combined with the old age it must reach to dominate and breed, it is especially vulnerable to extinction by human interference.

Direct removal by humans is the biggest threat to the species in some areas. Today, G. insculpta is legally protected from collection.

Wood Turtles have also suffered greatly from habitat loss. Intensive forestry, farming, or industrial or residential development can severely impact G. insculpta. Another threat to these turtles is the recent increase in numbers of predators, such as raccoons (Procyon lotor), which not only destroy turtle eggs and hatchlings, but can also kill adult turtles (Harding, 1985; 1991, 1997, pers.obs.).

The long-term future for this species is bleak unless its habitats are protected and the animals themselves are left alone. Wood turtles are listed as vulnerable by the IUCN and special concern in the state of Michigan, and they are in CITES appendix II.

Some more information...

Based on new scientific data, the scientific name of the wood turtle was recently changed from Glyptemys insculpta to Glyptemys insculpta. (Feldman and Parham, 2001; Holman and Fritz, 2001)

Contributors

David Armitage (editor), Animal Diversity Web Staff.

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

References

Bickham, J., T. Lamb, P. Minx, J. Patton. 1996. Molecular systematics of the genus *Clemmys* and the intergeneric relationships of emydid turtles. Herpetologica, 52(1): 89-97.

Burke, R., T. Leuteritz, A. Wolf. 1996. Phylogenetic relationships of emydine turtles. Herpetologica, 52(4): 572-584.

Carroll, T., D. Ehrenfeld. 1978. Intermediate-range homing in the wood turtle, *Clemmys insculpta*. Copeia, 1978: 117-126.

Conant, R., J. Collins. 1998. A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Third Ed., Expanded. Boston and New York: Houghton Mifflin.

Congdon, J., A. Dunham, R. van Loben Sels. 1993. Delayed sexual maturity and demographics of Blanding's Turtles (*Emydoidea blandingii*): Implications for conservation and management of long-lived organisms. Conserv. Biol., 7(4): 826-833.

Ernst, C., J. Lovich, R. Barbour. 1994. Turtles of the United States and Canada. Washington, D.C.: Smithsonian Institution Press.

Ewert, M., C. Nelson. 1991. Sex determination in turtles: Diverse patterns and some possible adaptive values. Copeia, 1991: 50-69.

Feldman, C., J. Parham. 2002. A molecular phylogeny for emydine turtles: taxonomic revision and the evolution of shell kinesis. Molecular Phylogenetics and Evolution, 22(3): 388-398.

Feldman, C., J. Parham. 2001. Molecular systematics of emydine turtles.. Chelonian Conservation and Biology, 4(1): 194-198.

Garber, S., J. Burger. 1995. A 20-year study documenting the relationship between turtle decline and human recreation. Ecological Applications, 5(4): 1151-1162.

Harding, J. 1985. Life History Notes: *Clemmys insculpta* (Predation and Mutilation). Herpetol. Rev. (SSAR), 16(1): 30.

Harding, J. 1999. Life History Notes: *Clemmys insculpta* and *Emydoidea blandingii*. Hybridization.. Herpetol. Rev. (SSAR), 30 (4): 225-226.

Harding, J. 1977. Record egg clutches for *Clemmys insculpta*. Herpetol. Rev. (SSAR), 8(2): 34.

Harding, J., T. Bloomer. 1979. The wood turtle, *Clemmys insculpta*, a natural history.. HERP: Bull. New York Herp. Soc., 15(1): 9-26.

Harding, J. 1991. A twenty year wood turtle study in Michigan: implications for conservation. Chapman University, Orange, California: In: Proceedings of the First International Symposium on Turtles and Tortoises: Conservation and Captive Husbandry.

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

Holman, J., U. Fritz. 2001. A new emydine species from the Middle Miocene (Barstovian) of Nebraska, USA with a new generic arrangement for the species of Clemmys sensu McDowell (1964) (Reptilia: Testudines: Emydidae). Zoologische Abhandlungen Staatliches Museum für Tierkunde Dresden, 51: 331-354.

Kaufmann, J. 1992. The social behavior of wood turtles, *Clemmys insculpta*, in central Pennsylvania. Herpetol. Monogr., 6: 1-25.

Kaufmann, J., J. Harding, K. Brewster. 1989. Worm stomping by wood turtles revisited.. Bull. Chicago Herp. Soc., 24: 125-126.

Saumure, R., J. Bider. 1998. Impact of agricultural development on a population of Wood Turtles (Clemmys insculpta) in southern Quebec, Canada. Chelonian Conservation and Biology, 3(1): 37-45.

Tinklepaugh, O. 1932. Maze learning of a turtle. Journ. Comp. Psych., 13: 201-206.

Tuttle, S. 1996. Master of Science Thesis: Ecology and Natural History of the Wood Turtle (*Clemmys insculpta*) in Southern New Hampshire. Keene, New Hampshire: Antioch New England Graduate School, Antioch University.

 
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Harding, J. 2013. "Glyptemys insculpta" (On-line), Animal Diversity Web. Accessed October 31, 2014 at http://www.biokids.umich.edu/accounts/Glyptemys_insculpta/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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