Species
Northern map turtle
Graptemys geographica
A river turtle of northwest Georgia with contour-line markings on its shell, like a map.
Photo D. Gordon E. Robertson (opens in a new tab) / Wikimedia Commons, CC BY-SA 3.0 (opens in a new tab)
At a glance
- Size
- Females up to about 27 cm shell length; males 10 to 16 cm
- Habitat
- Large rivers and lakes with basking logs
- Diet
- Snails, mussels and crayfish; males also insects
- In Georgia
- Rivers of northwest Georgia
- Rabies vector
- No
Identification
- Key marks
- Olive-brown shell with fine yellow lines like a map; low keel along the middle; small yellow spot behind the eye
- Told apart from
- Alabama and Barbour's map turtles, which have knobbed keels and live in other river systems
- Where to look
- Basking in groups on logs in rivers
Behaviour
Northern map turtles bask for long periods and are among the wariest turtles, diving at the first sign of people. Females have broad heads and strong jaws for crushing mussels and snails.
Why they matter
They are important predators of snails and mussels, including invasive species, and need clean rivers with fallen trees.
Reproduction and lifecycle
Nest — Dug in sand or soil near the river
Eggs — Usually 6 to 20
Incubation — About 50 to 70 days
Hatchlings — Grey-green with fine patterning
Maturity — Females take over ten years
Lifespan — Decades
Living around people
- Fallen trees left in the river give map turtles basking places.
Misconceptions
- Map turtles are named for being found on maps. The name comes from the contour-like lines on the shell.
Related species
Seasonal activity
When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Breeding | Jan: no | Feb: no | Mar: no | Apr: no | May: no | Jun: no | Jul: no | Aug: no | Sep: no | Oct: no | Nov: no | Dec: no |
| Active nests | Jan: no | Feb: no | Mar: no | Apr: no | May: no | Jun: no | Jul: no | Aug: no | Sep: no | Oct: no | Nov: no | Dec: no |
| Notes | Inactive in deep water | Inactive | Becoming active | Basking and courtship | Nesting | Nesting | Feeding | Hatching | Hatchlings emerge | Feeding | Slowing down | Inactive |
Where it lives
Recorded in 23 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.
United States
If you found one
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