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Diamondback terrapin project marks seven years

By Staff | May 27, 2020

SCCF Diamondback terrapin

The Sanibel-Captiva Conservation Foundation has several, long-term wildlife projects where species are marked with microchips (pit-tags), the notching of the carapace, clipping of scales, color-coded banding around the legs, photographing of unique characteristics or a combination of these techniques to identify individuals of a population.

By marking individuals, SCCF scientists can determine population estimates, seasonal activities, ontogenetic shifts or changes in appearance over time and longevity.

The diamondback terrapin (Malaclemys terrapin) is a brackish water turtle species that primarily lives in mangrove waterways in the local area. The SCCF has been studying terrapins since 2013 as part of the SCCF Diamondback Terrapin Project and many habitat and life history notes have been documented.

For example, a female terrapin (#40) was captured for the first time on May 7, 2013. At that time, she was an immature female with a carapace length of 112 millimeters (4.4 inches). She was also recaptured in 2014 and 2015, but had not been seen in five years.

Coincidentally, she was just recaptured on May 7, which is exactly seven years to the day of her initial capture at the same location. She is now a mature female with a carapace length of 169 millimeters (6.65 inches) that likely averages two to three clutches of egg per year, with an average clutch size of three to six eggs. The terrapins in the SCCF study are marked with scute notching, microchips and photography (carapace, plastron and head pattern).

SCCF Diamondback terrapin

A high percentage of the terrapins in the project show high site fidelity or philopatry, which means that they tend to stay throughout the year or return to a certain area seasonally. Others appear to be transient and arrive only at the study site as part of breeding aggregations and then leave.

On an annual basis, the SCCF samples the creeks where terrapins gather to breed and continues to document high recapture rates and also a mostly consistent quantity of transient adult terrapins and young recruits that are now large enough to enter the population in mangrove creeks. Hatchling and juvenile terrapins under 82 millimeters (3.2 inches) live in a different habitat.

To learn more about the terrapin study, visit “http://www.sccf.org/our-work/wildlife-and-habitat-management/diamondback-terrapin-project”>www.sccf.org/our-work/wildlife-and-habitat-management/diamondback-terrapin-project.

If you see a terrapin, try to take a picture and notify the SCCF at terrapin@sccf.org.