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Diamondback Terrapin - Watchable Wildlife

Quick Facts

A diamondback terrapin in the grass
Diamondback terrapin - Malaclemys terrapin
(Photo:Michael Unold)
  • The diamondback terrapin is the only turtle species in North America that lives in brackish water (mix of fresh and salt water). They come ashore only to nest.
  • Each plate of the shell is made up of keratin (like our fingernails!) and is unique to that turtle-just like a human fingerprint.
  • The gender of a turtle is influenced by temperature. Generally, a cooler nest produces males and a warmer nest produces females.
  • Females scoop out a six inch deep hole for their 4-15 eggs with their hind webbed feet and then cover them without looking back!
  • In the late 1800s to early 1900s turtle soup was a popular delicacy. Overharvesting greatly reduced populations. On May 1, 2018, the harvest of terrapins was closed in New York.
  • Terrapins continue to struggle with predation, pollution and development of habitat, and drowning in commercial and recreational crab pots.
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What to Watch for


Carapace (shell) length is 3 ½ -5 ½ inches in adult males, 6-9 inches in adult females, and 1-1 ¼ inches after hatching.

The head, neck and front part of the shell of a diamondback terrapin
Photo: Michael Unold


Deep diamond-like circular patterns on individual scutes (plates) on top of its gray to brownish-black shell. Conspicuous black spots and blotches on the head and neck of a light colored body ranging from white to gray; webbed feet with claws. The tail is longer and thicker in males compared to females.


Two sets of alternating J swirl shaped tracks imprinted in the sand, with a track that runs down the center created by the tail.

Where to Watch

They can be found in brackish waters of coastal salt marshes, tidal creeks, estuaries, bays, and coves.

They sometimes bask in the sun along creek banks at low tide or float motionless some distance from shore with just their head above the surface. Females can be found on beaches and in sand dunes when nesting.

Female diamondback terrapin laying eggs in the sand
Diamondback terrapin laying an egg
Photo: Eric Rulison

When to Watch

From late May until early July check the beaches for nesting females that retreat from the water to lay their eggs.

If spotted, make sure to keep some distance between you and the turtle, because if disturbed the turtle will abandon her nest.

More information about Diamondback Terrapin

Diamondback Terrapin Distribution Map

The Best Places to See Diamondback Terrapin

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