Panhandle Terrapin Project 2025 Report

by Rick O'Connor | Sep 22, 2025

Introduction

The diamondback terrapin (Malaclemys terrapin) is the only resident turtle within brackish water and estuarine systems in the United States (Fig. 1).  They prefer coastal estuarine wetlands – living in salt marshes, mangroves, and seagrass communities.  The literature suggests they have strong site fidelity – meaning they do not move far from where they live.  Within their habitat they feed on shellfish, mollusk and crustaceans mostly. In early spring they will breed.  Gravid females will venture along the shores of the bay seeking a high-dry sandy beach where they will lay a clutch of about 10 eggs.  She will typically return to lay more than one clutch each season.  Nesting will continue through the summer.  Hatching begins mid-summer and will extend into the fall.  Hatchings that occur in late fall may overwinter within the nest and emerge the following spring.  They live 20-25 years.

Fig. 1. The diamondback terrapin.
Photo: Molly O’Connor

Terrapins range from Massachusetts to Texas and within this range there are currently seven subspecies recognized – five of these live in Florida, and three are only found in Florida (Fig. 2).  However, prior to 2005 their existence in the Florida panhandle was undocumented.  The Panhandle Terrapin Project (PTP) was initially created to determine if terrapins did exist here.

Fig. 2. Terrapins of Florida.
Image provided by FWC

The Scope of the Project

Phase 1

The project began in 2005 using trained volunteers to survey suitable habitat for presence/absence.  Presence is determined by locating potential nesting beaches and searching for evidence of nesting.  Nesting begins in April and ends in September – with peak nesting occurring in this area during May and June.  The volunteers are trained in March and survey potential beaches from April through July.  They search for tracks of nesting females, eggshells of nests that were depredated by predators, and live terrapins – either on the beach or the heads in the water.  Often volunteers will conduct 30-minute head counts to determine relative abundance.  Between 2005 and 2010 the team was able to verify at least one record in each of the panhandle counties.

Phase 2

The next phase is to determine their status – how many nesting beaches does each county have, and how many terrapins are using them?  A suitability map was developed by Dr. Barry Bitters as a Florida Master Naturalist project to locate suitable nesting beaches.  Volunteers would visit these during the spring to determine whether nesting was occurring, and the relative abundance was determined using what we called the “Mann Method” – developed by Tom Mann of the Mississippi Department of Wildlife, along with the 30-minute head counts.  The Mann Method involved counting the number of tracks and depredated nests within a 16-day window.  The assumption to this method was that nesting females would lay multiple clutches each season – but they did not lay more than one every 16 days.  Going on another assumption, that the sex ratio within the population was 1:1, each track and depredated nest within a 16-day window was a different female and doubling this number would give the relative abundance of adults in this population.  Between 2007 and 2023 we were able to determine the number of nesting beaches in each county and relative abundance in three of those counties (see results below).

Phase 3

Partnering with the U.S. Geological Survey, we were able to move to Phase 3 – which involves trapping and tagging terrapins.  Doing this gives the team a better idea of where the terrapins are going and how they are using the habitat.  To trap the terrapins, we use modified crab traps (modified so that the terrapins had access to air to breath), seine nets, fyke nets, dip nets, and by hand – the most effective has been modified crab traps (Fig. 3).  These traps are placed in terrapin habitat over a 3-day period, being checked daily.  Any captured terrapins are measured, weighed, sexed, marked using the notch method, and given a Passive Intergraded Transponder (PIT) tag.  Some of the terrapins are given a satellite tag where movement could be tracked by GPS (Fig. 4).  We are now bringing on acoustic tagging for some counties.  This involves placing acoustic receivers on the bottom of the bay which will detect any terrapin (with an acoustic tag) that swims nearby.  Results are below.

Fig. 3. Modified crab traps is one method used to capture adults.
Photo: Molly O’Connor

Fig. 4. This tag with an antenna can be detected by a satellite and tracked real time.
Photo: USGS

Phase 4

This phase involves collecting tissue samples for genetic analysis.  Currently it is believed that the Ornate terrapin (Malaclemys terrapin macrospilota) ranges from Key West to Choctawhatchee Bay, and the Mississippi terrapin (M.t. pileata) ranges from Choctawhatchee Bay to the Louisiana/Texas border.  The two subspecies look morphologically different (Fig. 5) and the team believes terrapins resembling the ornate terrapin have been found in Pensacola Bay.  Researchers in Alabama have also reported terrapins they believe to be ornate terrapins in their waters as well.  The project is now working with a graduate student from the University of West Florida who is genetically analyzing tissue samples from trapped terrapins to determine which subspecies they are and what the correct range of these subspecies.  This phase began in 2025, and we do not have any results at this time.

Fig. 5. The Mississippi terrapin found in Pensacola Bay is darker in color than the Ornate terrapin found in other bays of the panhandle.
Photo: Rick O’Connor

Ornate Diamondback Terrapins Depend on Coastal Marshes and Sea Grass Habitats
Photo: Erik Lovestrand.

2025 UPDATE AND RESULTS

In 2025 we trained 188 volunteers across each county – including state park rangers and members of the Florida Oyster Corps.  47 (25%) participated in at least one survey.

We logged 345 nesting surveys and 17 trap days.

No seining or fyke nets were conducted in 2025.

Phase 1 – Presence/Absence Update

Phase 2 Nesting Survey – Update

¹ primary beaches are defined as those where nesting is known to occur.

² secondary beaches are defined as those where potential nesting is high but has not been confirmed.

³ FOE (Frequency of Encounters) is the number of terrapin encounters / the number of surveys conducted.

⁴ There was one deceased terrapin found by a tour guide in Baldwin County but was not part of the project.

⁵ There are potential nesting sites on Pensacola Beach that are technically in Escambia County but covered by the Santa Rosa team.  The Escambia team focused on the Perdido Key area.

Phase 3 Trapping/Tagging Update

We currently have 8 years of data.

Terrapins have been tagged in 7 of the 8 panhandle counties.

1483 captures, 1061 individuals.

2025 Capture Effort

Preliminary information subject to revision. Not for citation or distribution.

Satellite Tagging Information

Due to the size of the tags – only large females are satellite tagged at this time.

Big Momma – tracked for 188 days – averaged 0.16 miles.

Big Bertha – tracked for 137 days – averaged 35.83 miles.

2025 Tracking Effort

Phase 4 Update

This phase began in 2025 and there are no results at this time.

Summary

2025

17 trainings were given in 7 of the 8 counties of the Florida panhandle (including Baldwin County AL).

188 were trained; 47 (25%) conducted at least one survey.

345 surveys were logged; terrapins (or terrapin sign) were encountered 49 (14%) of those surveys.

Every county had at least one encounter during a nesting survey.

17 trapping days were conducted; 46 terrapins were captured; 37 (83%) were captured in modified crab traps; 7 were captured by hand; 1 was captured in a dip net.

8 terrapins were tagged for tracking; 6 acoustically; 2 with satellite tags.

Since 2007

511 have been trained.

1449 surveys have been logged; 347 encounters have occurred; Frequency of Encounters is 24% of the surveys.

Discussion

Phase 1

We have shown that diamondback terrapins do exist in the Florida panhandle and in Baldwin County AL.

Phase 2

We currently have 13 primary nesting beaches we are surveying weekly during nesting season across the panhandle.  There were 17 secondary nesting beaches surveyed and most likely there are many more to visit.  Nesting seems to be more common in late spring, but the Frequency of Encounters has been declining since 2023.  This could be due to less terrapin activity but could also be due to evidence being difficult to find.  We will continue to monitor to see how this trend continues.

Phase 3

The team has captured 1483 terrapins, the majority of which were from the eastern panhandle.  Satellite tagged females suggest more than one has traveled over 30 miles from where they were tagged.  This goes against the idea that terrapins have strong site fidelity.  However, all the terrapins tagged were large females (due to size of the tags) so we are looking at the movements of only the larger females – not the population as a whole.  The movements of these females also suggest they may use seagrass beds as much as the salt marshes.

Training for volunteers occurs in March of each year.  If you are interested in participating, contact Rick O’Connor – roc1@ufl.edu.