Glyptemys insculpta


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Glyptemys insculpta
Species Authority: (LeConte, 1830)
Common Name/s:
English Wood Turtle
French Clemmyde Sculptée
Clemmys insculpta (LeConte, 1830)
Testudo insculpta Le Conte, 1830
Taxonomic Notes: Previously this species was known as Clemmys insculpta, under which name it appeared in IUCN Red Lists from 1996 to 2006; paraphyly of the traditional genus Clemmys (sensu McDowell, 1964) required placement of insculpta and muhlenbergii into Glyptemys (Holman and Fritz 2001, Parham and Feldman 2002).

Assessment Information [top]

Red List Category & Criteria: Endangered A2cd+4c ver 3.1
Year Published: 2011
Date Assessed: 2010-08-01
Assessor/s: van Dijk, P.P. & Harding, J.
Reviewer/s: Horne, B.D., Mittermeier, R.A., Philippen, H.-D., Quinn, H.R., Rhodin, A.G.J., Shaffer, H.B. & Vogt, R.C
Quantitative data on the overall population decline of Glyptemys insculpta are not available, but the general perception is that some populations hold stable while others (possibly most) are in slow decline. Considering the long generation time of the species (about 36–47 years) the cumulative decline over the past 100 years is likely to have exceeded 50%, much of this decline is irreversible, and declines are likely to continue in places. Thus, an Endangered designation under criteria A2cd+4c appears warranted.

Glyptemys insculpta was evaluated as Vulnerable A1abcd+2cd in 1996.
1996 Vulnerable

Geographic Range [top]

Range Description:Glyptemys insculpta inhabits the Great Lakes region as far as eastern Minnesota, through the northern Appalachians to northern Virginia, and up to Nova Scotia (Iverson 1992).
Canada (New Brunswick, Nova Scotia, Ontario, Québec); United States (Connecticut, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Ohio - Possibly Extinct, Pennsylvania, Virginia, West Virginia, Wisconsin)
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: In suitable habitat, Wood Turtles can reach substantial densities, ranging from five to over 100 animals per hectare of prime riparian habitat, but such stream valleys only represent a small portion of the overall area. Wood Turtles tend to be localized and associated with relatively less developed remote hill and montane regions (review in Ernst and Lovich 2009).
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Glyptemys insculpta uses a variety of habitats focused on clear, hard-bottomed streams and rivers and adjoining forest, woodland and some fields. Deep pools with permanent flow are essential for successful hibernation.

Wood Turtles feed on a variety of vegetation, mushrooms, earthworms, slugs and other invertebrates, and carrion.

Males reach 23 cm carapace length (CL), females 20 cm CL. Maturity is reached at 14–18 years (19–20 cm CL) in males, and at 14–18 years (16–18 cm CL) in females. Females usually produce a single clutch, but second clutches have been reported; clutches comprise 8–11 (range 3–20) eggs. Incubation takes about 67 days (range 42–82). Hatchlings measure about 37 (28–40) mm. Longevity exceeds 40 years (review in Ernst and Lovich 2009). Generation time has not been calculated but is likely similar to that of Emys (Emydoidea) blandingii, i.e. at the order of 36–47 years (Harding, pers. comm. Aug 2009).
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): Habitat degradation, fragmentation and destruction are widespread in Wood Turtles' areas of occupancy, from residential and recreational developments (particularly second homes/cabins) and associated infrastructure, as well as forestry practices in the public lands where the main populations are located.

Wood Turtles are valued as pets, and continued collection of animals for the (illegal) pet trade represents a threat to some populations.
The terrestrial habits of Glyptemys insculpta in summer lead to road mortality as well as fatal encounters with recreational vehicles and agricultural machinery.

Predation by (subsidized) raccoons is significant, and believed to result in no recruitment in Michigan (J. Harding, pers comm Aug 2009). Subsidized predators may become a more significant issue as residential and recreational developments penetrate further into wood turtle habitat.

Glyptemys insculpta is well documented to have shifted its range northward with the end of the past ice age; global warning is likely to tip southern populations towards extinction, while northern populations might expand into new territory.

Conservation Actions [top]

Conservation Actions: Glyptemys insculpta is included in CITES Appendix II and is protected in most areas of its occurrence. Substantial populations occur in protected areas and lands safeguarded from major development.

Remaining populations of Wood Turtles need to be considered carefully in land management practices, particularly forestry on public lands. Measures to minimize accidental mortality need further research, awareness, extension and implementation; this potentially includes roadside fencing and underpasses, and higher blade height on agricultural mowers. Regulations against collection of animals from the wild need full enforcement.

Bibliography [top]

Ernst, C.H. and Lovich, J.E. 2009. Turtles of the United States and Canada. Second edition. Johns Hopkins University Press, Baltimore.

Holman, J.A., & Fritz, U. 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 St. Mus. Tierkunde Dresden 51(20): 331-353.

IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.1). Available at: (Accessed: 16 June 2011).

Iverson, J.B. 1992. A Revised Checklist with Distribution Maps of the Turtles of the World. Richmond, Indiana. (Privately published).

Parham, J.F., & Feldman, C.R. 2002. Generic Revision of Emydine Turtles. Turtle and Tortoise Newsletter 6: 28-30.

Citation: van Dijk, P.P. & Harding, J. 2011. Glyptemys insculpta. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 19 April 2014.
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