The dune fields of the panhandle barrier islands closely mimic those in the deserts of the American southwest. With rolling hills of sand (less the rock), small, spaced shrubs, and high temperatures, hiking through the dunes reminds me a lot of hiking the deserts and canyonlands out west. Oh… and you rarely see wildlife in both habitats.
It’s not that wildlife is not present, its just not visible – and this would be true for both habitats. These systems are more open, easier to spot predator and prey, and the temperatures can be extreme. Because of this the animals who reside here are more active at other times of the day and we are made aware of their presence by tracks or scat.
In winter the temperatures in the dunes can get quite cold. Being in the eastern United States, and closer to the warm Gulf Stream, the atmosphere is more humid and cold temperatures can feel even colder – the “wet chill” everyone talks about. Add to this the winds from the north and it can be an unpleasant place to be out and about. Many plants have gone dormant not producing flowers or seed, and the leaves falling or shriveled and brown, and you have very little for the herbivores to feed on. When conditions get like this animals have basically two options. One, hunker down, hibernate, wait for conditions and food sources to improve. Two, leave – head south where conditions are more favorable. Either way, you do not see them.
A hike in winter finds little wildlife moving about. Birds are common. Many have flown south from harsher conditions further north and seem to enjoy being out. Unless it is unseasonably cold and windy, you can find a variety of passerines (songbirds) in the shrubs and bushes of the dunes. Mockingbirds, cardinals, and mourning doves are often seen. There are also unique species more common up north. Christmas time is a popular time for the Audubon Society to conduct their annual bird counts. Many volunteers often log species rarely seen during other times of the year.
Mammals and reptiles are not often seen during the daylight hours. Some reptiles may come out of hiding on days when the sun is bright, and the winds are low. They will find a windbreak near a dune and bask in this sunlight for a few hours. But to see them it is one of those “being in the right place and the right time”. Daytime is short this time of year and they are not out very long.
Mammals being endothermic can move around. They are still not frequently seen during the daylight hours because the habitat is too open and hunting not as successful. There are also a lot of humans on our islands now and many mammals are not fond of this and tend to avoid us. So, they change their pattern of activity to other times. Animals who are active during the daytime are called diurnal. Those more active at night are nocturnal. And those more active at dawn and dusk are called crepuscular. During the winter many mammals tend to be more crepuscular because the evenings can get quite cold no matter what the wind is doing. If they are not hibernating, they will hunt for a few hours at dawn or dusk and then hide during the colder parts of the evenings.
During my winter hikes I have seen primarily passerine birds, and occasionally an armadillo. But most sign of wildlife are the tracks of raccoons, coyote, and deer.
In the spring things change. The earth is tilting more towards the sun, the days become longer, and the cold air masses are met by the more tropical warmer ones. Temperatures and rainfall increases. These warmer temperatures are more inviting to daytime foraging for prey. Ephemeral ponds form due to the increase rainfall. Island amphibians take advantage of this mating and laying their non-cledoic eggs in these ponds while they are still there. The warmer evenings are filled the calls of male frogs seeking females. Mammals are still more crepuscular and nocturnal, but it is a time when your chances of spotting one during the daylight hours increases. Not only is the weather better but the food sources are as well, and some have been hibernating for a couple of months and are quite hungry. Hunger will push them to be more active during daylight than they would otherwise be. The same can be said for reptiles. Snakes moving during daylight is more common this time of year.
This is also the time for mating. It will be warm for several more months and this is the best time to raise a small offspring. The temperatures are warmer (conducive to growth), food more abundant (needed for growth), and you avoid the colder temperatures that can kill small animals. Males of these species are out and about seeking females and defending territories. Nesting birds of several varieties can be found building such nests. Turtles and snakes are breeding and seeking good locations to lay their eggs. With all of this comes more activity and more encounters by human hikers.
Let’s not forget the insects. Actually, you can find these creatures at all times of the day in all seasons. Insects are one of the most resilient groups of animals on the planet, and their high diversity – even on barrier islands – supports this. In the spring when the rains come and the ephemeral ponds are available, insects begin to breed and fill the skies. Spring is a very active time in the dunes.
Summer brings the heat – particularly late summer. Like the deserts of the southwest, temperatures can rise above 100°F and it is not the best time to be out and about. Much of the wildlife becomes more crepuscular or nocturnal. I have noticed when doing snake surveys, that the snakes may be moving at dawn but by 8:00-9:00am, when you begin to feel the heat of the day, you find no more. They have moved to the shade or a burrow somewhere. BUT the lizards begin to move. Lizards are a popular food for snakes, and it makes sense they would be more active when snakes are not. However, the sand is hot, and birds are also predators. So, lizards, like the six lined skink (Aspidoscelis), move VERY fast across the hot sand from one bush to another. I even notice the passerine birds becoming less common as the heat increases – it is hot out there. Interestingly human activity seems to increase when the temperatures are at their highest. We tend to sleep later than most animals this time of year.
The fall brings some relief from the heat. As the earth begins to tilt away from the sun and the days become shorter, the temperatures begin to drop, and it is more comfortable coming out during daylight hours. Humans are still around so many will still avoid daylight but it also a time to prepare for winter. Seeking food resources and eating as much as possible is the rule for many. For some it is also a time for breeding. Carrying for offspring in a den or burrow over winter is an option for some species. Because of this they are out seeking mates and may be seen during daylight hours when doing so. This would include some of the snakes like the eastern diamondback rattle snake (Crotalus) and the cottonmouth (Agkistrodon).
Though dunes seem void of wildlife there are actually many species that reside here and even more than transient there from other parts of the island. Hikes through the dunes can bring magnificent sunrises and sunsets, just as you see in the deserts out west, and – if you are there at the right time and not moving too much – some really neat wildlife encounters can occur. But further back on the island exist the maritime forest. Here there are more creatures and more encounters. This will be the focus of Part 6.
The open sandy beach is one of the hardest habitats to live in on a barrier island. There is no where to hide and almost nothing to eat. Add to this the direct wind and waves from the Gulf of Mexico and you have a barren landscape with continuous climate and ocean energy. But creatures do live here.
Before we go further let’s define a few terms. The beach is actually the dry sandy portion of this environment. The area where the sand squeaks as you walk through it, the place where you set your chairs, umbrellas, and lunch for your day at the beach. The berm is the harder packed sand near the waters edge. The place where you like walk when you walk the beach (it’s easier) and the waves wash over every few seconds. Living in these two would be very different. Second, we will define resident and transient. A resident is a creature who actually resides there. A transient is just passing through but lives somewhere else.
As you look across the beach you will notice there is NO WHERE to hide from the elements… except beneath the sand. One of the more common creatures who lives beneath the is the ghost crab (Ocypode quadrata). This crustacean digs burrows down to the water table where they can keep their gills wet and this can be as deep as four feet. On these flat beaches they are easy target for predators. They have several ways to deal with the problem. (1) Their compound eyes are on stalks above their head to give them a wider, and longer, range of view. (2) They are white in color and blend in with the quartz sand well. (3) They are more active at night, nocturnal. (4) They are very fast.
The trick to speed is to break contact with the ground. If you were to ask someone “what is the fastest way to get to Los Angeles?” They would answer “flying”, and this would be correct. Birds are some of the fastest creatures around. They fly. They lift off the ground and do not touch again until they reach their destination. It does not get any better than that. Cheetahs are very fast as well. But if you watch them in slow motion, you will see they are basically leaping from one point to the next. They touch the ground very few times over a certain distance. They are trying to fly but cannot. If look at video of a human, or centipede, or slug. Not sot good. Crabs are crustaceans and by definition they have 10 legs. When they move across the surface, they usually use eight of those (two being their claws). The same is true for the ghost crabs. But when they decide to run, they only run on three of them. They raise the other five above their heads. This means fewer legs touching the sand which means they are faster.
Food is another issue. Due to direct high wind (filled with salt), plants do not grow on the beach. Hence the classic food chain (plant – herbivore – carnivore) cannot exist. So, what do ghost crabs eat? They are scavengers. They emerge from their burrows, usually at night, to seek what dead creatures the tide may have washed in. Post storms are particularly good feeding times. Surf fishermen along the Gulf beach often catch hardhead catfish and, not liking them, often toss them on the beach to die. In the evening the ghost crabs will drag these to the entrance of their burrows where they feast for quite a while. They eventually clean to fish to the bone leaving their “hard head” (the skull). When you look at the skull from underneath it appears to be Jesus on the crucifix. These skulls are often collected and sold in novelty stores as “crucifix fish”.
Another prize for ghost crabs are sea turtle eggs. Sea turtles are obvious transients to the beach environment, coming here only during nesting season. The females usually approach the beach close to where they were born at night. She will labor her way across the beach to the first dune line, though some will lay theirs in the open beach area. She could spend several hours digging a hole three to five feet deep. Loggerhead Sea Turtles (the most common on our beaches) simply dig a hole. The Green Sea Turtle will use her flippers to dig a form for her body before digging the nest. She will deposit about 100 eggs before burying them and returning to the Gulf. Ghost crabs, and other beach transients like coyotes, fox, and raccoons, will find and raid these nests.
The wrack (a line of debris that includes seaweed, shells, and other flotsam from the Gulf) offers a variety of food for ghost crabs. Another who is often found scavenging the wrack are shore birds. There are numerous species of terns, gulls, pipers, and plovers that will pick through the wrack for food.
The berm is a tougher place to make home. You are in the surf zone and must deal with breaking waves every few seconds. As you might expect, there are no plants here, and very few animals. Those that do reside here bury in the sand knowing that the surf will most likely expose them and could carry them to another location. The two most common animals in this zone are the mole crab and the coquina.
The mole crab (Emerita talpoida) is also known by surf fishermen as the “sand flea”. It is a small oval shaped crab that has a hard paddle like telson to dig into the wet sand tail first. With its head exposed it will extend antenna that are covered with small hair-like structures designed to collect plankton from the water that covers it when the waves come in. The surf often exposes them, but they flip over and dig back in very quickly.
The coquina (Donax variabilis) is a small clam that comes in a variety of colors (hence it’s species name). Like all clams, it has a fleshy foot which it uses to quickly dig into the wet sand covering most of its body. Like the mole crab, it exposes its head into the surf extending two fleshy tubes called siphons that draw water into the clam where it can collect planktonic food.
Predators do exist here, but they are not residents. They would include transient fish that come close to shore waiting for the surf to wash these small animals into the Gulf. One of the more common is the Florida Pompano. Surf fishermen like to use “sand flea” baskets, dragging them through the sand near the waters edge to capture the mole crabs for bait seeking these tasty fish. Others would include an assortment of shorebirds like sand pipers and plovers who run to the wet sand when the surf recedes back into the Gulf probing for the mole crabs and coquina, then quickly running back towards the beach when the surf returns.
The diversity of life in the beach-berm zone is not high, but this is a tough place to make a living. Ghost crabs, mole crabs, and coquina clams have all adapted to living here and have done quite well. But more wildlife prefers the dunes. It is a little easier there and the next stop in Part 5 of this series.
The habitats of a barrier island are defined and driven by the plant communities there. Seeds from the mainland must first reach the new island and they can do so using a variety of different methods. Some come by wind, some by water, some by birds and other wildlife. Some of these germinate, some do not. Those that do, do so on a sandy island with little or no relief and must deal with the winds off the Gulf, which has salt spray. Many of these mainland plants cannot tolerate this and never make it. But some can… and do.
These early plant communities are known as the pioneer community – meaning the earliest settlers. In the process of succession pioneer communities are made of creatures that can tolerate the harshest conditions, the early days of ecosystem development. There are usually few nutrients, extreme climatic conditions, and for the animals, few prey to select from. But these pioneers are adapted to survive in these conditions and over time alter the conditions so that other creatures can move in.
For the barrier islands, grasses seem to be the plants who do best in the early stages of succession. Though small shrubs and trees may reach the island, the high winds and salt spray will not allow growth. There are numerous species of grasses that can live here, the most famous are the sea oats (Uniola paniculata). This grass can be found on the smallest of barrier islands. Their fibrous root system runs beneath the ground sprouting new grasses all over. Their seed heads blow with the wind starting new populations of plants on other locations and the landscape is soon dominated by them. However, there are other species as well. Panic grass (Panicum amarium), salt hay (Spartina patens), and beach elder (Iva imbricata) to name a few. All these grasses can tolerate the wind and salt spray as well as the low nutrient, low rainfall often found on these islands. They also all have fibrous roots systems that not only connect grasses across the land scape but also trap blowing sand – forming dunes.
The dunes closest to the Gulf are dominated by grass due to the higher winds and salt spray there. These are called the primary dunes and create one of the first habitats on the island for wildlife. The primary dunes vary in height and how far from the Gulf they range but they do form a wind break for portions of the island landward of the Gulf.
Here smaller shrubs and plants like seaside golden (Solidago sempervirens) and seaside rosemary (Ceratiola ericoides) can grow. With less wind their seeds will germinate and survive. What wind is still there forces the plants to grow in a round shape resembling green sheep on a white field, instead of white sheep on a green field. My professor referred to them as “beach sheep”. This area of the barrier island is called the secondary dune and includes other species such as false rosemary (Conradina canescens), square flower (Odontonychia corymbosa), and sandhill milkweed (Asclepias humistrata). Though they cannot tolerate the high winds as grasses do, they do have to tolerate climatic extremes and low rainfall.
These secondary dunes vary in elevation and can become taller than the primary dunes. In the low areas between dunes are areas where freshwater water can collect and form ephemeral ponds. These areas are known as swales and create unique habitats much sought after by some wildlife. More bog like plants grow here such as water dock (Rumex orbiculatus) and marsh pink (Rhexia nashii) but also includes the carnivorous plants like the sundew (Drosera rotundifolia). There are many insects who used these ephemeral ponds and many spiders and sundews to take advantage of this.
Behind the larger secondary dunes, the wind is even less, and the dune wind breaks higher. Here trees can germinate, if they can tolerate the climatic conditions, and grow. Though the species that grow out there are some of the same you find on the mainland, here they grow differently. Barrier island trees tend grow out, not up, to avoid direct contact with wind and salt spray. And, when they do reach the wind the portion of tree directly facing the wind tends to be stunted in growth, giving it the appearance that someone has “combed” the tree back towards the bay – something they call wind sculpting. Trees that seem do well in what they call the tertiary dune include sand live oak (Quercus geminata), pine (Pinus sp.), and magnolia (Magnolia grandiflora). Yaupon holly (Ilex vomitoria) and even cactus like the prickly pear (Opuntia humifusa) and the devil’s joint (Opuntia pusilla) can be found growing here.
Tertiary dunes are some of the largest on the island, with elevations reaching 50 feet or more. These provide excellent wind breaks from the Gulf and allow the formation of salt marshes along the bay side shoreline. Marshes are habitats dominated by grass, but these grasses must be able to tolerate periods emersed in salt water, at least at high tide. Close to the dunes the marsh is dominated by dense stands of black needlerush (Juncus roemerianus). In some locations within the needlerush marsh are areas of bare sand known as salt pans. These are low areas within the marsh where water remains when the tide recedes. These small marsh ponds begin to evaporate in the intense sunlight and the salinity increases to a level where it kills off much of the plant life leaving an area of bare sand. These salt pans are used by some wildlife on the islands. Eventually you will reach the waters edge where smooth cordgrass (Spartina alterniflora) grows. This marsh grass can tolerate water for longer periods than needlerush and supports both island wildlife and estuarine fisheries.
As you can imagine, the process of establishing the pioneer community of grasses on a new, small sand bar, to an island filled with dunes and vegetation takes time – years, decades, maybe centuries – but eventually it will reach what we call the climax community and provides a variety of habitats to support wildlife.
In part 3 we will begin to look at how animal species colonize the islands as these habitats form.
The diamondback terrapin (Malaclemys terrapin) is the only resident brackish water turtle in the United States. Ranging from Massachusetts to Texas. This estuarine turtle spends much of its time in coastal wetlands such as marshes and mangroves but have been found in seagrasses. They feed primarily on bivalves, have strong site fidelity, and live to be 20-25 years in the wild. Studies on their basic biology and ecology have been published throughout their range with the exception of the Florida panhandle.
In 2005 the Marine Science Academy at Washington High School (MSA) was asked to survey coastal estuaries within the Florida panhandle to determine whether diamondback terrapins (Malaclemys terrapin) existed there.
Methods – Presence/Absence
To determine presence/absence MSA identified boat ramps near suitable terrapin habitat. “Wanted” signs were placed at these ramps with our contact information and beach walk surveys were conducted seeking terrapins or terrapin sign. Since the best time to conduct beach surveys is May and June (not suitable for high school), that part of the project moved to program director and his family.
Surveys were conducted and terrapins were found in each of the six counties between the Alabama state line and the Apalachicola River.
Methods – Relative Abundance
The next question was to assess their relative abundance. To do this the team followed a protocol used by Tom Mann with the Mississippi Department of Natural Resources we call the “Mann-Method”. There are recognized assumptions with this method.
Every sexually mature female within the population nests each season.
Each female will lay more than one clutch per season but never more than one in a 16-day period.
You know where all nesting beaches are located.
The sex ratio to males is 1:1.
Going on these assumptions, every track, nest, or depredated nest on the nesting beach within a 16-day window is equivalent to one female. If the sex ratio is 1:1, then each female is equivalent to one male, and you have a relative abundance of the population. That said, there are publications suggesting the female: male ratio could be 1:3 or even 1:5 in the Florida panhandle. We would report the relative abundance as 1:1 – 1:5 for each nesting site.
Another method of estimating relative abundance is conducting a 30-minute head count. From a fixed location, or drifting in a kayak across the lagoon, every head spotted in a 30-minute period is logged. The assumption here is that if the average number of heads / 30-minutes increase or decreases over time, the relative abundance within the population is increasing or decreasing as well.
Trained volunteers conducted these surveys at least once a week at each nesting beach from April 1 to June 30 each year.
2022 Data Update
47 volunteers were trained in March of 2022; 21 (45%) participated in surveys.
173 surveys were conducted; 346 hours were logged.
Terrapins (or terrapin sign) were encountered during 43 of the surveys – Frequency of Encounters = 25% of the surveys.
Surveys occurred in Escambia, Santa Rosa, Okaloosa, and Bay counties. Encounters occurred in all counties except Bay.
Beach Surveys – 2022
County
# of Surveys
# of Encounters
Frequency of Encounters
Escambia
29
4
.14
Santa Rosa
58
15
.26
Okaloosa
43
25
.58
Bay
43
0
.00
TOTAL
173
43
.25
Head Count Surveys – 2022
County
# of Surveys
Range of Heads/30-min
Mean of Heads/30 min
Escambia
0
ND
ND
Santa Rosa
2
0-49
24
Okaloosa
17
0-32
11
Bay
0
ND
ND
Estimated Relative Abundance Using the Mann-Method
County
Nesting Beach Surveyed
Ratio 1:1
Ratio 1:3
Ratio 1:5
Relative Abundance for the County
Escambia
1
4
8
12
4-12 terrapins
Santa Rosa
1
12
24
36
2-48 terrapins
2
2
4
6
3
16
32
48
Okaloosa
1
24
48
72
2-72 terrapins
2
4
8
12
3
2
4
6
Bay
1
ND
ND
ND
ND
2
ND
ND
ND
Year
County
Relative Abundance
2008
Santa Rosa
14-35
2009
Santa Rosa
14-35
2010
Santa Rosa
32-80
2011
Santa Rosa
10-50
2015
Santa Rosa
12-30
2018
Santa Rosa
16-40
2021
Santa Rosa
4-12
Escambia
8-24
Okaloosa
4-70
2022
Santa Rosa
2-48
Escambia
4-12
Okaloosa
2-72
Terrapins Captured – tagged – and tissue samples collected
County
# of Terrapins Captured/Tagged/Tissue Collected
Escambia
1
Santa Rosa
2
Okaloosa
2
Bay
0
TOTAL
5
Results
At the beginning of this project Objective 1 was to determine whether diamondback terrapins existed in the Florida panhandle. That objective has been met – they do, we have at least one verified record in all six counties between the Alabama state line and the Apalachicola River.
Objective 2 is to determine the relative abundance within these counties. The first step in addressing this objective is to determine where terrapins are nesting in each. Nesting beaches have been identified in Escambia, Santa Rosa, and Okaloosa counties – but we are not sure whether ALL of the nesting beaches in those counties have been identified.
Known nesting beaches in Escambia County have changed over time. Two of the three nesting locations have become inactive in recent years and other potential beaches have not been adequately surveyed to determine whether they are being used or not. Based on one active nesting beach, the relative abundance of terrapins in Escambia County is low. Estimations using the Mann-Method suggest that there are between 2-24 terrapins present.
There are numerous potential nesting locations in Santa Rosa County but only a few have been adequately surveyed. Currently there two active nesting beaches being surveyed and the relative abundance at these has run between 30-80 animals at one location, 6-36 at the other. Going with this, there are between 6-80 terrapins present.
Okaloosa has only recently been surveyed. There are currently three active nesting beaches being surveyed and most of the nesting is occurring at one of those. The location of these beaches suggests that these are all animals of the same group or clad and part of the same population. Based on the results there are between 2-72 terrapins present.
Surveys are JUST getting underway in Bay County and no surveys have been conducted in Walton.
These data suggest that the relative abundance in each county is less than 100 and small when compared to other locations within their range.
Discussion
The results are only as good as the data being used. The volunteers participating in this project are doing an excellent job, but the frequency of nesting beach visits and head counts surveys are lower than needed to make accurate assessments. Several of the nesting beaches are in difficult places for volunteers to reach frequently and thus not surveyed as frequently as we would need. More volunteer participation could help this. Keep in mind that the Mann-Method also focuses on nesting females and males, immature females are not accounted for so the population would be slightly larger than estimated using this method. That said, we do believe that the populations in this part of their range are most likely smaller than other parts of their range. These surveys will continue. Questions or comments can be directed to Rick O’Connor, Florida Sea Grant, University of Florida IFAS Extension, roc1@ufl.edu.
Florida has a love-hate relationship with this animal. Some find them cute and adorable, others find them a pest and a nuisance, either way there is no ignoring this guy. They are everywhere and yes – they can make a mess of your lawn and garden. So, for those who are not so in love with the creature – what can be done?
Let’s first meet the animal.
There are about 20 species of armadillo found in Central and South America but there is only one in the U.S., the Nine-Banded Armadillo (Dasypus novemcinctus). The Nine-Banded Armadillo is originally from South America and there were several different species of armadillos that made the trek from South to North America prior to the ice age. But after the ice age it seemed no armadillos were present in the U.S. After the ice age, the Nine-Banded Armadillo expanded north into Mexico, but it seems could not cross the Rio Grande. That is until Americans began to settle the area. Prior to American settlement, armadillos were hunted for food, and the land on both sides of the river was regularly burned. The American settlers ceased the burning and the Native Americans declined in numbers, so hunting pressure declined as well. Many armadillos were probably brought across intentionally, but others who managed to swim across, and armadillos can swim, now found suitable habitat with the decreased burning. They had arrived and began expanding both east and west across the southern U.S. However, the Mississippi River presented another barrier they could not deal with.
The introduction in Florida was a different story. Apparently in the 1920s and 30s they were released by humans. One release appeared to be an escape from a small zoo. Another was from a circus. There are reports of armadillos riding cattle cars on trains from the west and this allowed them to cross the Mississippi. In the 1920s bridges were built across the river for a new invention called the automobile. All of this led to the invasion and the animals are now here, they are also expanding north.
Armadillos like warm/wet climates. They prefer forested areas or grasslands and, again, can swim small rivers and creeks easily. It has been reported they can hold their breath up to six minutes and have been seen literally walking along creek bottoms.
They feed primarily on a variety of small invertebrates such as grubs, snails, beetles, and even cockroaches (many of you will like that). They like to feed in wet areas or loose sandy soils where digging is easier. Unfortunately, your lawn is a good place to hunt. They rarely, but do, feed on small reptiles and amphibians and eggs.
They breed in the summer but delay egg implantation so that birth is in the spring. They typically give birth to quadruplets. The armor of the young is not hard at first but hardens over time and does provide protection from large predators like panthers, bears, and alligators. They typically live 12-15 years, but some have reached the age of 20.
So… now you know the animal… for those who do not want them, what can be done?
Based on an article from UF IFAS Extension, not a lot. Typical methods of deterring wildlife have not worked. Poisons, smells, and even using firearms has not relieved the homeowner of the problem. One study looked at trapping and found that in general it is hard to get them to enter. In this study they caught one armadillo every 132 trap nights – low percentages. Another study looked at baits and found crickets and worms worked best, but the smell of other armadillos in the trap also lured them. One colleague mentioned the need for solid wood traps and he baits them with nothing but the shells of roadkill as had good success. He mentioned the designs of these wooden traps are online. You can get plans to build them, and you can also purchase pre-made ones. Once captured they can be relocated but the trapper should be aware that armadillos have many peg-like teeth and very sharp claws for digging. HANDLE WITH CARE. It is also known that armadillos can carry leprosy, though cases of leprosy being transmitted to humans are rare. None the less, handle with care.
For more information on this animal, contact your county extension office.
Since 2005 we have been tracking and monitoring diamondback terrapins in the Florida panhandle. For those of you who are not familiar with the animal, it is a turtle in the family Emydidae. Emydid turtles include what we call “pond turtles” and also include the box turtles. Terrapins differ from the others in that (a) their skin is much lighter, almost white, and (b) they like salt water – more accurately, they like brackish water.
The animals range from Massachusetts to Texas and within this there are seven subspecies. Five of these live in Florida, and three only live in Florida. In the Florida panhandle we have two subspecies: the Ornate terrapin (Malaclemys terrapin macrospilota) and the Mississippi terrapin (M.t. pileata). It is believed the that the Mississippi terrapin only exist in Florida within Pensacola Bay – more on that in a moment.
There are literally no peer reviewed publications on terrapins from the Florida panhandle… none. And this was how the Panhandle Terrapin Project began. The first objective for the project was to determine if terrapins even existed here. We began surveying for evidence of terrapins in 2005 using students from Washington High School in Pensacola. The project quickly fell to myself and my wife due to the best time to do terrapin surveys was May and June. And the worst time to work with high school students was May and June. Between 2005 and 2012 we were able to verify at least one terrapin record in each of the panhandle counties. Yes… terrapins exist in the Florida panhandle.
The second objective was to assess their population status. To do this we used what I call the Mann-Method. Tom Mann, Mississippi Department of Wildlife, had developed a method of using nesting surveys to estimate relative abundance of terrapins within a population. Terrapins tend to have strong site fidelity – they are “home bodies” – and do not move from marsh to marsh. If you can find their marsh, you can find their nesting beaches. If you can find their nesting beaches you can use the Mann-Method to assess their relative abundance.
There are a couple of assumptions with the Mann-Method. (1) You are assuming every female in the population nest every year – we are not sure that is true. (2) You are assuming that each female will lay more than one clutch of eggs each season – we do believe this is true. (3) You are assuming that each female will not lay more than one clutch in a 16-day period – we are not sure this is true. (4) You know where all of the nesting beaches are – we are not sure we do. (5) The sex ratio of male to female is 1:1 – we are sure that is not the case. One study suggested that in the panhandle the ratio may be 1:3 in favor of males, another suggested 1:5 in favor of males.
Based off this model, and its assumptions, during a 16-day period of the nesting season, each track/nest would be an individual female. Using 1:1, 1:3, and 1:5 as your sex ratio you can get an estimate of relative abundance.
Another method for estimating relative abundance is counting the number of heads in a 30-minute period. It is understood that if I see different heads during periods of the survey, I may be seeing the same head, but the argument is that if I typically see 10-15 heads during a 30-minute and over time that becomes 15-20, or 20-25, the relative abundance of terrapins is increasing – and visa versa.
And we now have a third and fourth objective. A third objective is to capture animals to place tags on them. Doing this can give us a better idea of how these terrapins are using the habitats in the panhandle, how far they may travel and how they are getting there. The fourth objective is to obtain tissue samples for genetic analysis. The purpose of this is to determine whether the populations in Pensacola Bay are Mississippi terrapins, Ornate terrapins, or hybrids of the two.
Since 2015 this work is now being conducted by trained volunteer citizen scientists – people like you – and we do the trainings in March if interested.
So… how did things go in 2022?
In 2022 we trained 47 volunteers to be survey beaches. 25 (53%) participated in at least one survey.
173 surveys were conducted between April 2 and July 31 at 14 nesting beaches between Escambia and Bay counties. Encounters with terrapins, or terrapin sign, occurred during 43 of the 173 surveys (25%) and three terrapins were captured for tissue and tagging.
Escambia County
Number of Surveys
Dates
Number of Surveys / Day
29
Apr 3 – Jul 31
0.2
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
4
.18
No surveys conducted
4-12
Santa Rosa County
Number of Surveys
Dates
Number of Surveys / Day
58
Apr 4 – Jul 5
0.6
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
15
.26
N=2, 0-49, X = 24
30-90
Okaloosa County
Number of Surveys
Dates
Number of Surveys / Day
43
Apr 18 – Jul 15
0.5
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
25
.58
N=17, 0-32, X = 11
30-90
No surveys were conducted in Walton County
Bay County
Number of Surveys
Dates
Number of Surveys / Day
43
Apr 2 – Jun 30
0.5
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
0
.00
No surveys conducted
0
Summary of 2022 Terrapin Season
Surveys of nesting beaches occurred in four of the five counties in the western panhandle.
Terrapins were encountered in each of these cand captured in two of them.
The relative abundance ranged between 0 (Bay County) to between 30-90 individuals (Santa Rosa and Okaloosa counties) and was about 64-192 animals for the entire western panhandle (depending on the sex ratio you use).
We are sure that we have not found all of the nesting beaches in this region and will continue to look for more.
We are awaiting results from the tissue sampling to determine whether we have a distinct population of Mississippi terrapins in Pensacola Bay, but more samples will be needed.
We need to place satellite tags on some females to get a better idea of how they travel through the system.
And our relative abundance numbers suggest that populations in the Florida panhandle are relatively small compared to others within the terrapin range.
More needs to be done and we will continue to survey each spring. If you are interested in becoming a member of the Panhandle Terrapin Project, contact me (Rick O’Connor) at roc1@ufl.edu.