Graptemys geographica inhabits the Mississippi-Missouri-Ohio-Tennessee system, the Great Lakes system, and the Susquehanna, Delaware and Hudson systems. A record from eastern Massachusetts needs confirmation (Iverson 1992). There are three known localities in Oklahoma, two recent and the other historic (in a river reach that is now a reservoir) (Lindeman pers. comm. 2010).

The Common map turtle inhabits an area from southern Quebec and northwestern Vermont where it lives in the St. Lawrence drainage. Its range extends west through the Great Lakes and into southern Wisconsin and eastern Minnesota, west of the Appalachians, south to Kansas, northeastern Oklahoma, Arkansas, Tennessee, Alabama and then northwestern Georgia. It also occurs in the Susquehanna River system located in Pennsylvania and Maryland and also in the Delaware River (HSUS 1999).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Southwestern Quebec (north to a few hundred km up the Ottawa River; Daigle et al. 1994), southern Ontario, and northwestern Vermont (St. Lawrence drainage) to central Minnesota, south in Mississippi River drainage to Arkansas, northern Alabama (to Tombigbee drainage above Fall Line), and eastern Tennessee, west to eastern Kansas; Ohio River drainage from West Virginia to Illinois. Isolated populations in Delaware and Susquehanna river drainages of Pennsylvania, Maryland, and New Jersey; and in Hudson River, New York (McCoy and Vogt 1990).

Length: females are 7 to 10.5 inches and males are 3.5 to 6.5 inches.

Common map turtles get their name from the markings on the carapace. The light markings resemble waterways on a map or chart (Conant and Collins 1998). The lines on the carapace are a shade of yellow or orange and are surrounded by dark borders. The rest of the carapace is olive or grayish brown. The markings on the older turtles may be barely visible because of darker pigment. The carapace is broad with moderately low keel. The hind of the carapace is slightly scalloped shaped due to the scutes (Harding 1997). The plastron of an adult map turtle tends to be plain yellowish color (Conant and Collins 1998). The head, neck and limbs are dark olive, brown or black with thin yellow, green or orangish stripes. There is also a oval spot located behind the eye of most specimens (Harding 1997). There is sexual dimorphism in size and shape. The females are much larger than the males. The males also have a more oval carapace with more distinct keel, narrower head, longer front claws, and a longer thicker tail. The males vent also opens beyond the edge of the carapace whereas the female's open up the carapace (Harding 1997). The young map turtles have a pronounced dorsal keel and patterns on the plastron consist of dark lines bordering the scutes (Conant and Collins 1998). A hatchling has rounded gray or grayish-brown carapace about 1 in long. The pattern is light circular markings. The stripes located on the head and limbs are just like the adults (Harding 1997).

Length: 27 cm

See McCoy and Vogt (1994) for a key to species in the genus Graptemys.

• Terrestrial
• Freshwater

Common map turtles inhabit ponds, river-bottoms and lakes. The abundance of aquatic vegetation is preferred (Kirkpatrick 1999). They prefer large bodies of water and areas with fallen trees and other debris for basking (Conant and Collins 1998).

Aquatic Biomes: rivers and streams

Comments: Slow rivers and lakes with mud bottoms, basking logs, and abundant aquatic vegetation. Often in mill ponds, oxbows, and river overflow ponds. In Kansas, occurred exclusively in small shady streams over rock and gravel substrate (Fuselier and Edds 1994). May occupy burrows in banks when inactive (Minton 1972). Wintering sites include river bottoms (e.g., in hollows, among rocks or other objects) (e.g., see Graham and Graham, 1992, Can. Field-Nat. 106:517-519; Graham et al. 2000); in Vermont, 7 of 15 monitored adult females hibernated in the same site in two consecutive years (Graham et al. 2000). Basks on muskrat houses, logs, etc. Eggs are laid in nest dug in soft soil or sand, generally away from beaches (Ernst and Barbour 1972).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Common map turtles are omnivores (Kirkpatrick 1999). The feeding always takes place in the water. The adult females, due to their large heads and strong jaws eat larger prey than the males. The females consume snails, clams, and crayfish. The males eat aquatic insects, snails, and smaller crustaceans. Both are also known to eat dead fish and some plant material (Harding 1997).

Comments: In Wisconsin, ault females eat primarily mollusks; also crayfish and insect larvae; males probably more insectivorous (Vogt 1981). In Missouri, the small gastropod Elimia potosiensis was by far the most important food item for adults (White and Moll 1992). In some areas, aquatic insect dominate the diet.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

100,000 to >1,000,000 individuals

Daily and annual movements varied greatly among individuals in a river in central Pennsylvania (up to several thousand meters in a few days, or virtually no movement over several years; Pluto and Bellis 1988).

In Vermont, range length for 6 adult females (with sonic tracking tags) was 1.5-8.0 km along the Lamoille River; total movements outside the hibernaculum ranged from 3.1-15.4 km; some individuals moved downstream to Lake Champlain (2.7 km) and along the lakeshore as much as 2.2 km before returning to the hibernaculum (Graham et al. 2000).

Comments: Most active from April to September. Sluggish activity may occur under ice in winter. Variously reported as sleeping in water at night or foraging at night (cf. Vogt 1981 and Ernst and Barbour 1972).

Average lifespan

Status: captivity: 5.5 years.

Common map turtles breed in the spring and the fall. Most mating takes place in deep waters. The nesting period lasts from May to July. Unshaded sites with sandy soil is highly preferred (Harding 1997). The female usually chooses well-drained areas for depositing the eggs (Kirkpatrick 1999). The nest cavity is dug with the hind feet. The size of the clutch is between 6 to 20. The eggs are oval and have a flexible shell that is about 3.2 cm. After the eggs are laid the cavity is filled. They hatch between 50 to 70 days of incubation and most emerge in August or September. When a nest hatches late, the common map turtle has been known to overwinter in the nest (Harding 1997). The female usually lays two or multiple clutches in one breeding season. The sexes of the young are determined by the temperature. 25°C incubation will give majority of males whereas 30-35°C will yield more females (Kirkpatrick 1999).

Average age at sexual or reproductive maturity (female)

Sex: female: 5110 days.

Lays 1 or more clutches of up to 20 eggs, late April or May to early or mid-July. Mean clutch size in Missouri was about 10, with some females producing at least 2 (possibly 3) clutches/year (White and Moll 1991). Hatchlings emerge from mid-August to September or overwinter in nest and emerge in spring.

Common map turtles are less tolerant to poor conditions than most other turtles (Kirkpatrick 1999). Humans are hurting the turtles by numerous methods. Pollution, waterfront development is destroying their breeding sites, and automobiles are also a killer of these turtles when they are migrating to the breeding sites (HSUS 1999). Fishing also has a negative affect on them, they get caught on the fishing hooks (Harding 1997). Populations have been reduced or eliminated in some areas, but they do still persist in suburban rivers and agricultural lands (Harding 1997).

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: no special status

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Highly to moderately vulnerable.

Global Short Term Trend: Relatively stable to decline of 30%

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: Water pollution that negatively impacts molluscan prey, waterfront development that destroys or degrades nesting habitat, and automobile traffic that kills females traveling overland to nest have reduced populations in some parts of the range (Ernst et al. 1994).

Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed

These turtles are sometimes, rarely, used as food. The pet trade hasn't taken an interest in the common map turtle, probably due to the difficulty of maintaining them in captivity. They also don't affect the fishing industry, other than getting caught on the hooks, since they do not eat any of the game fish (Harding 1997).

Comments: Lamb et al. (1994) conducted a mtDNA-based phylogenetic analysis of turtles in the genus Graptemys and discovered three monophyletic lineages: G. pulchra group (including G. pulchra, G. gibbonsi, G. ernsti, and G. barbouri); G. pseudogeographica group (including G. pseudogeographica, G. nigrinoda, G. flavimaculata, G. oculifera, G. versa, G. caglei, and G. ouachitensis); and G. geographica. Overall genetic divergence was relatively low, and G. pseudogeographica, G. nigrinoda, G. flavimaculata, G. oculifera, and G. versa all shared the same mtDNA genotype. There was no evidence of infraspecific variation in any species. Walker and Avise (1998) reviewed these data and suggested that the Graptemys complex has been taxonomically oversplit at the species level.

McDowell (1964) concluded that the genus Graptemys should be included in the genus Malaclemys, but this arrangement generally has been rejected (e.g., see Dobie 1981 for information on osteological differences between the two genera).