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Those Terrific Terrapins

Those Terrific Terrapins

They are marvelous creatures and there are very few panhandle residents who know what they are. My wife and I were introduced to Diamondback Terrapins by George Heinrich in 2005. George was the president of a nonprofit, Florida Turtle Conservation Trust, and a member of the Diamondback Terrapin Working Group, a national group of terrapin researchers and educators. He, and these organizations, were very interested in the status of terrapins in the Florida panhandle… so Molly and I took that job on.

 

Diamondback terrapins (Malaclemmys terrapin) are the only true brackish water resident turtle in the United States. They range from Cape Cod MA down the entire eastern seaboard, across the Gulf of Mexico to Brownsville TX. Within that range there are 7 described subspecies, 5 of those found in Florida, 2 found in the Florida panhandle. These estuarine turtles prefer salt marsh and mangrove habitat. They are very reclusive and difficult to find – hence why most locals have never seen nor heard of them. When I talk about them to the public I get responses such as… “do you mean tarpon?” “I find those in my yard all of the time” (probably a different species), “aren’t those from up north?” and “never heard of them”… they are not fish so they could be found in your yard if you live along the fringes of a salt marsh, they are up north – but they are here also.

Diamondback terrapin found in Wakulla County.  Photo: Molly O'Connor

Diamondback terrapin found in Wakulla County.
Photo: Molly O’Connor

 

In 2005 Molly and I were asked to survey the panhandle and determine if terrapin populations still exist. We decided to take that job on and then expand to determine their population size and whether those populations are increasing or decreasing. The coastal panhandle extends from Escambia County (on the Alabama state line) to Jefferson County (Aucilla River), but due to existing funding we could only survey to the Apalachicola River. This would include six counties: Escambia, Santa Rosa, Okaloosa, Walton, Bay, and Gulf. We verified at least one record of a terrapin in each county. We discovered the larger the expanse of salt marsh – the higher probability of terrapins; thus those counties with relatively little salt marsh (such as Okaloosa) would have fewer/smaller terrapin populations.

 

But marsh alone is not enough. Terrapins need high ground in which to lay their eggs. High ground within a marsh is not a common thing. Research shows that terrapins will travel up to 5 miles in search of suitable nesting; which means a terrapin could be found in your neighborhood even if no marsh is visible. Unlike sea turtles they are “home-bodies” rarely leaving the marsh where they were born. They spend time forging for shellfish (particularly the snail called marsh periwinkle – Littorina irorata) and basking on and in the mud. They can be seen at the surface with their heads peering at you – they seem to be very curious.

 

Marsh periwinkles will climb cordgrass to avoid predation by blue crabs and terrapins.  Photo: Molly O'Connor

Marsh periwinkles will climb cordgrass to avoid predation by blue crabs and terrapins.
Photo: Molly O’Connor

 

Once we confirmed that terrapins were still in the panhandle we then began work on how many. To do this we needed to find their nesting beaches. Terrapin nesting season is about the same as that of sea turtles (May 1 – Aug 1); some nesting may occur after that but few. Unlike sea turtles they nest during daylight hours and prefer sunny days over cloudy/raining ones. They like to nest at high tide – thus finding a suitable location that is out of the way of potential flooding by the rising bay – however this does not account for severe storms. They typically lay about 10 eggs in their nest, cover and disguise, and then leave it to its fate. Unfortunately in many nesting areas, its fate is to be uncovered and consumed by predators – particularly raccoons. Molly and I would kayak salt marshes searching for suitable nesting beach. Once found, we would walk the beach looking for sign of nesting. If nesting was found this would be recorded and we would then begin 16-day monitoring trips. It is assumed that each sexually mature female within the population will nest once every 16 days; and they will nest more than once each year. Signs of nesting include tracks (which are counted), and egg shells from a nest that was raided by a raccoon (which were logged and removed). Occasionally we would come across a nesting female. We would allow her to complete the nesting activity and then capture her for measurements and photographs. We would mark her with a notch on the margin of the carapace (top shell) and release her (we did not have the funding for PIT tags). We would also set modified crab traps to capture them. Terrapins have a habitat of entering crab traps (probably more for the bait than the crabs) and becoming entrapped. Unless found within 15-30 minutes, they will drown. Our modified crab traps were tall enough that terrapins could reach the surface (even at the highest tide) and get a breath of air. We would set traps for 5 day periods and (if we caught any at all) would only capture during the first day or two. Terrapins are smart and we found that after day 2 most would approach our traps, observe our handy work, and swim away. With the data from these two activities we could get a rough idea of how many terrapins were in this population and how they changed over time.

 

The marshy habitat terrapins love.   Photo: Molly O'Connor

The marshy habitat terrapins love.
Photo: Molly O’Connor

 

We focused our population surveys to our home counties of Santa Rosa and Escambia counties. We were able to identify 1 nesting beach in Escambia and 2 in Santa Rosa (we have since found a 3rd). We never caught a terrapin in Escambia but had good success at one of the two beaches in Santa Rosa. That population had approximately 50 individuals living within it. From 2007 to 2012 the population remained relatively stable. In 2012 I changed jobs and have not had a chance to re-survey. I plan to do this in 2016.

 

This year we trained 24 volunteers to assist us in locating and monitoring nesting beaches. They did find a new nesting beach in Santa Rosa and will begin monitoring nesting activity and trapping next year.

 

These are fascinating creatures and one of the most beautiful turtles you will ever see. Some have asked me about state protection for them. They are listed as a freshwater turtle with FWC thus you cannot possess more than two, cannot have any eggs, and cannot sell them.

 

If you have questions about diamondback terrapins, are interested in participating in terrapin surveys in Escambia and Santa Rosa counties, or would like to begin your own surveys in your county. Contact me (Rick O’Connor) at roc1@ufl.edu or (850) 475-5230.

PG

Author: Rick O’Connor – roc1@ufl.edu

Sea Grant Extension Agent in Escambia County

Rick O’Connor

Permanent link to this article: http://okaloosa.ifas.ufl.edu/newsletters/2015/10/02/those-terrific-terrapins/