Graptemys pseudogeographica

Geographic Range

False map turtles populate areas of the Mississippi and Missouri Rivers and their basins in Arkansas, Iowa, Indiana, Illinois, Kansas, Kentucky, Louisiana, Minnesota, Missouri, Nebraska, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, and Wisconsin.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

False map turtles are found predominantly in large rivers and backwaters, but also in bayous, oxbows, lakes, ponds, sloughs, drowned forests, and occasionally marshes. They prefer water with slow currents, places to bask, and abundant aquatic vegetation. They can sometimes be found in the swiftly flowing main channels of large rivers.

• Habitat Regions
• temperate temperate
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Wetlands
• marsh marsh

Physical Description

The carapace is olive, brown, or black with dark blotches that have yellow lines around them. The lines sometimes form a web pattern over the entire carapace and may or may not have blotches; this is where it gets the name false map turtle because the lines form a sort of map across the shell. These markings are brighter on young turtles than on adults. The carapace has serrate margins and a vertebral keel that is more prominent in the young. The plastron is cream to yellow colored, but the young have a dark pattern there as well. False map turtles have olive to brown skin with yellow lines on their legs, tail, chin, and neck. The head is moderately broad and on some there is a backwards L behind each eye.

Males are 9 to 15 cm in length and females are 12 to 27 cm in length. Adult females, on average, are 1.50 to 1.74 times larger than adult males and have wider heads. Adult males have elongated second and third fore claws, a longer tail, and their anal opening is posterior to the carapacial margin. Females in captivity were found to have a mass from 1100 to 1800 g.

Two sub-species of Graptemys pseudogeographica are currently recognized: G. pseudogeographica pseudogeographica and G. pseudogeographica konii . G. pseudogeographica konii has a more extensive plastron pattern.

False map turtle eggs are elliptical and average 32 to 41 mm in length, 18 to 26 mm in width, and weigh about 6 to 11 g. The hatchlings are nearly round with patterns similar to the adults of their subspecies. The keel on the first three vertebra of the carapace is well developed and the posterior rim of the carapace is more serrate than on the adults. Also, hatchling plastron patterns are darker than adult plastron patterns.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes shaped differently

Development

False map turtle hatchlings remain in the nest until the yolk sac is completely absorbed. The hatchlings leave the nest and have to find their way to the water where they live independently.

Incubation temperature of false map turtle nests influences hatchling head pattern, frequency of scute anomalies, and determines the sex of the hatchlings. Eggs incubated at 25 °C or lower are predominately male and eggs incubated at 30 °C or higher produce mostly females. Incubation periods ranged from 52 to 73 days for nests producing all females and 58 to 85 days for nests producing only males.

• Development - Life Cycle
• temperature sex determination

Reproduction

Male false map turtles identify a potential mate using visual and olfactory cues; the olfactory cues come from the female’s anal vent. Once a female is found, there is a male courtship display where the male first strokes his potential mate’s head and neck with his foreclaws. The male then drums his foreclaws over the female’s eyes. If she remains motionless, the male will then attempt to mate with her. Copulation lasts from 15 seconds to over 4 hours and is facilitated by the male hooking his tail around the female’s tail.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Graptemys pseudogeographica mate twice a year in April and again in October and November. Nesting season lasts from mid-May to late July, with the first clutch laid from mid-May to mid-June. Nests are excavated during the day with most clutches being deposited in the morning. Large groups of female false map turtles can be found near nesting beaches waiting environmental factors to become favorable for nesting. Nests are located anywhere from 5 to 150 m from the water in open sand areas or areas containing low shrubs. The female digs the nest with her hind feet to be 10 to 16 cm deep. After the eggs are laid they are covered and packed down with sand. Females can lay 2 to 3 clutches a year with clutch sizes of 8 to 22 eggs.

Male false map turtles sexually mature at 4 to 6 years and females sexually mature at about 8 to 14 years.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Beyond the female providing the egg with yolk, creating the nest, and laying the eggs, there are no other parental investments made by false map turtles.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

A male G. pseudogeographica konii that was caught as a juvenile, lived for 35 years and 5 months at the Columbus Zoo. It is impossible to reliably estimate the ages of individuals over 15 years because the rings become less and less visible as they shed their epidermal scutes.

Behavior

Graptemys pseudogeographica activity varies geographically, but usually lasts from late March to mid-October. They spend most of the day basking in the sun on muskrat lodges, logs, rock piles, sand bars, or stumps that are located near the shore. False map turtles stretch their hind limbs, spread the webbing between their toes, and extend their head and forelimbs when they are basking in the sun. By stretching out in this manner it allows grackles to remove leeches from their neck and leg cavities. When the turtles are basking they are extremely wary and difficult to approach; therefore entrance into the water by one turtle is usually followed by all those basking in the general vicinity. During the winter in the northern regions, they burrow 10 to 30 cm into the river bottom or use the entrance of a muskrat lodge for an overwintering site. False map turtles emerge from overwintering sites when water temperatures are 4 to 7 °C, usually in April.

• Key Behaviors
• terricolous
• natatorial natatorial
• diurnal diurnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• daily torpor
• social social

Home Range

Female false map turtles have home ranges that are larger than those of male false map turtles because they move from overwintering areas to nesting areas to feeding areas and back to overwintering areas. However, movement data is sparse.

Communication and Perception

False map turtles use touch and body language (postures and movements) to communicate. Male turtles display tactile behaviors during courtship; the male uses his fore claws to drum over his potential mate’s eyes.

• Communication Channels
• visual visual
• tactile tactile
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

False map turtles are generalist omnivores. The difference in size between males and females provides a partitioning of food resources. Females eat mollusks, ( Vallisneria , Potamogeton , Lemna , and insects including caddisflies ( Trichoptera ), mayfly larvae ( Ephemeroptera ), and damselfly larvae ( Zygoptera ). Males eat the same insects as females, along with beetles ( Coleoptera ), flies ( Diptera ), other insect larvae, mollusks, fish carrion, and small amounts of vegetation.

• Primary Diet
• omnivore omnivore

• Animal Foods
• fish
• carrion carrion
• insects
• mollusks
• terrestrial worms
• aquatic crustaceans

• Plant Foods
• algae

Predation

False map turtles are very timid and will quickly flee when approached. They rarely attempt to bite when handled, but may empty their bladder.

Red foxes , raccoons , otters , and maggots of the fly Metoposarcophaga importans are predators of their nests and eggs.

Ring-billed gulls , crows , grackles , red-winged blackbirds , and great blue herons are predators of emerging hatchlings. Bass , catfish , and pike are predators to the hatchlings once they have reached the water. Rice rats are predators of young turtles.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

False map turtles are predators of mollusks, insects, worms, algae, and other plant material and prey to foxes, raccoons, otters, birds, and some types of fish. Grackles remove leeches from the leg and neck cavities of the turtles while they are basking. In addition, false map turtle eggs can be a host to fly maggots.

Economic Importance for Humans: Positive

False map turtles are good beginner turtles as pets; however they are sensitive to water quality so close attention to their water quality is necessary.

• Positive Impacts
• pet trade pet trade

Economic Importance for Humans: Negative

There are no known adverse affects of G. pseudogeographica on humans.

Conservation Status

False map turtles are not currently considered threatened. Turtle populations throughout the United States are affected by collection for the pet trade, freshwater habitat destruction, and water pollution.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Michelle Stinson (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

References

Ernst, C., R. Barbour, J. Lovich. 1984. Turtles of the United States and Canada . Washington and London: Smithsonian Institution Press.

U.S. Army Corps of Engineers, 2005. "Environmental Laboratory" (On-line). Accessed October 03, 2005 at http://el.erdc.usace.army.mil/emrrp/turtles/species/false.html .

Vogt, R. 1993. Systematics and Ecology of the False Map Turtle Complex Graptemys Pseudogeographica . Ann Arbor, Michigan: A Bell & Howell Company.