Species
Barbour's map turtle
Graptemys barbouri
A river turtle of southwest Georgia whose females grow twice as long as males and crush snails with enormous heads.
Photo novvictan (opens in a new tab) / iNaturalist, CC BY 4.0 (opens in a new tab)
At a glance
- Size
- Females up to about 33 cm shell length; males usually 9 to 13 cm
- Habitat
- Rivers with limestone bottoms, snags and fallen trees
- Diet
- Females eat snails and mussels; males eat insects
- In Georgia
- The Flint and Chattahoochee river systems of southwest Georgia
- Rabies vector
- No
Identification
- Key marks
- Olive shell with a row of dark-tipped knobs along the midline; light blotch between the eyes; females have very broad heads
- Told apart from
- Alabama map turtle, which lives in different rivers farther north and west
- Where to look
- Basking on snags in the middle of the river
Behaviour
Barbour's map turtles are one of the most striking examples of males and females looking like different animals: females have huge heads and jaws for crushing mussels and snails, while the small males hunt insects. They bask on logs well out in the current and dive at once when disturbed.
Why they matter
They are found only in the Apalachicola river system of Georgia, Alabama and Florida, so Georgia's rivers carry a large part of the world's population. Fallen trees left in rivers are what they need to bask and feed.
Reproduction and lifecycle
Nest — Dug on sandbars and banks
Eggs — Usually 3 to 11, in several clutches a year
Incubation — About 60 to 80 days
Hatchlings — Small, patterned with fine lines
Maturity — Females take over ten years
Lifespan — Decades
Living around people
- Leaving fallen trees in rivers gives map turtles their basking places.
- Discarded fishing line entangles basking turtles.
Misconceptions
- The big-headed and small turtles are different species. They are females and males of the same one.
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 on cold days | Basking on warm days | Active | Courtship | Nesting on sandbars | Nesting | Nesting | Hatching | Hatchlings emerge | Feeding | Slowing down | Mostly inactive |
Where it lives
Recorded in 3 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.
If you found one
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