Spotted turtle (Clemmys guttata)

KingdomAnimalia
PhylumChordata
ClassReptilia
OrderTestudines
FamilyEmydidae
GenusClemmys (1)
SizeMaximum length: 13.6 cm (2) (3)

The spotted turtle is classified as Endangered (EN) on the IUCN Red List (1).

As its common name implies, this small turtle is easily recognised by the distinctive yellow to orange spotting on its smooth, brownish-black upper shell (carapace) (2) (4). This pattern of spotting extends onto the dark upper surface of the head and limbs (4), while the lower surfaces of the legs and neck are orange to pink or salmon-red (3). There is also usually a large yellow or orange blotch on each side of the head (3). The lower shell (plastron) is yellow to orange with large black patches on each scute, which normally become darker and more extensive with age (3). Males tend to have brown eyes, a tan, brown or black chin and a slightly concave lower shell, while females have orange eyes, a yellow chin, and a flat lower shell (3).

The spotted turtle occupies a fragmented range across north-eastern North America, primarily along the eastern seaboard and the Great Lakes region of the U.S. and Canada (2) (3) (4).

This semi-aquatic turtle is usually found in shallow bodies of water including bogs, marshes, swamps, sedge-meadows, woodland streams and brooks, permanent and seasonal pools and ponds (1) (4). This species also wanders onto land when travelling between wetlands and to nest, and moist terrestrial sites are sometimes used for aestivation and hibernation (1) (5).

Spotted turtles spend the winter hibernating, sometimes communally, usually on the muddy bottoms of fairly shallow waterways characterised by a slow, steady flow of water (6). Individuals are most commonly seen in spring when basking on logs, stumps, grass mats and tussocks, or searching for nest sites (2) (6) (7). Courtship and mating activity begins soon after emergence from winter dormancy, with copulation usually occurring in shallow waters (3), and typically involving the male chasing the female, often nipping her legs and shell margins (6). Multiple males may also fight with each other for the right to court a single female (6). Breeding can occur throughout the active season, but peaks in late May to early June (2), and sperm is stored until needed to fertilize the eggs (7). Nesting occurs from mid- to late June, primarily at night (2). Clutches of two to seven eggs are deposited in a nest dug in sand or soft soil on rocky outcrops, in a sunny location (2). The number of clutches laid each year varies with latitude; in the north, less than one clutch per year is laid, while up to three clutches per year are laid in the south (8). The natural incubation period may last 73 to 83 days (5), with faster development at higher temperatures (3). Most young emerge from their nests in August or September, but overwintering in the nest has been reported (3) (5). The sex of hatchlings is determined by nest temperature, with cooler temperatures producing mostly males and warmer temperatures producing females (2). Meanwhile, the adults often aestivate in the mud bottom of waterways or in muskrat burrows or lodges during the hot summer months (5). It is not known exactly why these turtles aestivate, but it may be related to declines in food abundance, to avoid desiccation or to avoid predation (9). Come late October or early November, spotted turtles typically return to flooded puddles and ponds once more to over winter under the ice until late February or late April, depending on latitude (6).

Spotted turtles have the potential to live up to 65 years for males and 110 years for females, but these small turtles are highly vulnerable to predation (10). When threatened they will quickly dive into the water and bury themselves in the bottom mud (11). During the winter hibernation period, muskrats are the primary predator (11).

Spotted turtles feed on a variety of plant and animal foods, most of which are taken in the water. Animal matter forms the bulk of the diet and includes worms, slugs, snails, crustaceans, adult and larval insects, frogs, tadpoles and fish carrion, supplemented by algae, leaves, soft aquatic plants and water lily seeds (2) (3) (6).

Spotted turtle numbers are declining due to unsustainable collection for the pet trade, habitat destruction and fragmentation, road mortality, agriculture, and pollution (2) (12). The drainage of wetlands, deepening of marsh habitats in favour of waterfowl populations, and the conversion of wetlands into agricultural and residential land has resulted in the loss, fragmentation, and modification of the spotted turtle’s habitat. This has left remaining spotted turtles living in very small, isolated subpopulations, which are more vulnerable to the effects of inbreeding, over-collection for the pet trade and predation (7) (11). In addition, road related mortality is thought to be a significant factor for nests and hatchlings, as well as female adults as they travel over land to nest (4) (6). In Ontario, pollution of aquatic habitats by substances such as DDT and PCB’s is also thought to be a problem for some spotted turtle populations (6). Predators such as raccoons, dogs, snapping turtles, skunks, foxes and other small mammals are responsible for the low recruitment of juveniles, preying most heavily on eggs and hatchlings, but occasionally also on adults (4) (6). Unfortunately, the spotted turtle’s life history traits, namely high egg (and probably hatchling) mortality, low reproductive potential in the wild, delayed sexual maturity (7 to 14 years), balanced by a long potential adult breeding life, deem it highly vulnerable to population collapses when faced with these threats (2) (10). If adult survivorship is reduced through factors such as human exploitation, road mortality or increased predator levels, populations are inevitably unable to produce and successfully raise enough offspring to recover depleted numbers, leading eventually to local extinctions (2) (11).

Spotted turtles are legally protected to some degree from exploitation in most states and provinces in which they are found, but protection is not yet consistent or universal over the turtle's range (2) (5). In Canada, the spotted turtle is listed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (2004) and is listed as a Specially Protected Reptile (Schedule 9) in the Fish and Wildlife Conservation Act (1997). In the U.S. the spotted turtle is not currently listed in the US Federal Endangered Species Act; however, it is listed in 22 of the states in which it occurs (2). Furthermore, there is insufficient protection of its wetland habitat, a matter which needs addressing if the species is to be given a good chance of long-term survival (4).

For more information on the spotted turtle see:

Authenticated (29/02/2008) by Dr. Jacqueline Litzgus, Assistant professor, Laurentian University, Ontario.
http://biology.laurentian.ca/Laurentian/Home/Departments/Biology/Faculty_and_Staff/Professors/litzgus/litzgus.htm

  1. IUCN Red List (June, 2011)
    http://www.iucnredlist.org
  2. Litzgus, J.D. (2004) Status Report on the Spotted Turtle, Clemmys guttata. Committee on the Status of Endangered Wildlife in Canada (COSEWIC), Environment Canada, Ottawa, ON. Available at:
    http://dsp-psd.pwgsc.gc.ca/Collection/CW69-14-382-2004E.pdf
  3. Ernst, C., Lovich, J. and Barbour, R. (1994) Turtles of the United States and Canada. Smithsonian Institution Press, Washington D.C.
  4. Centre for Reptile and Amphibian Conservation and Management: Spotted Turtle Fact Sheet (November, 2006)
    http://herpcenter.ipfw.edu/outreach/accounts/reptiles/turtles/Spotted_turtle/SpottedTurtleFactSheet.pdf
  5. Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (1997) Turtles of the World. ETI Information Systems Ltd, Netherlands. Available at:
    http://ip30.eti.uva.nl/BIS/turtles.php
  6. Trent University Biology Department: Kawartha Turtle Watch (February, 2008)
    http://web.archive.org/web/20050221234448/www.trentu.ca/biology/turtlewatch/Spotted.htm
  7. Canadian Amphibian and Reptile Conservation Network (February, 2008)
    http://www.carcnet.ca/english/reptiles/species_accounts/turtles/Clemmys/clemmys2.html
  8. Litzgus, J.D. and Mousseau, T.A. (2003) Multiple clutching in southern spotted turtles, Clemmys guttata. Journal of Herpetology, 37(1): 17 - 23.
  9. Litzgus, J.D. and Brooks, R.J. (2000) Habitat and temperature selection of Clemmys guttata from a northern population. Journal of Herpetology, 34(2): 178 - 185.
  10. Litzgus, J.D. (2006) Sex differences in longevity in the spotted turtle (Clemmys guttata). Copeia, 2006(2): 281 - 288.
  11. Harding, J. (1997) Amphibians and Reptiles of the Great Lakes Region. University of Michigan Press, Michigan.
  12. Burke, V.J., Lovich, J.E. and Gibbons, J.W. (2000) Conservation of freshwater turtles. In: Klemens, M.K. (Ed) Turtle Conservation. Smithsonian Institution Press, Washington, D.C.