Northern Diamondback Terrapin

Malaclemys terrapin

Terrapins live their lives in the bay and nest in sandy areas along the shore. Road crossings are extremely hazardous but a necessary part of life. Photo: Ben Wurst

Physical: Diamondback Terrapins have wedge-shaped carapaces (top shells) that range from gray-brown to black, and a lighter, greenish-yellow plastron (bottom shell)   Carapace length ranges from 4 to 9 inches, with females being generally larger than males.

Habitat: M. terrapin terrapin are found in brackish waters of salt marshes, tidal creeks, and estuaries along the Atlantic Coast from Cape Cod to Cape Hatteras.  The diamondback terrapin is the only turtle that lives in brackish water for its entire life.

Feeding: Terrapins feed on a variety of fishes, marine snails, invertebrates, mollusks, carrion, clams, crabs, and worms.  They feed more actively during high tide, or when the marsh is flooded.

photo of terrapin crossing sign

Breeding: Adult terrapins mate in early spring. Females lay clutches of 4-18 eggs from early June to mid-July in sandy beaches and upland gravel areas above the high tide line. Females are sexually mature at 7 years. Eggs incubate for 9-15 weeks; they hatch faster in warmer soil.  The sex of hatchlings is determined by soil temperature, which is known as temperature dependent sex determination (TSD).  More females are produced with warmer soil temperatures.

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