Though this is titled late winter, it did not feel like winter on this walk. The air temperature was 75°F. There was a blanket of fog over the beach, and it felt slightly humid and sticky, but with a cooler feel than we have in summer. It is true that Punxsutawney Phil did not see his shadow this year – signaling an early spring, and the weather today supported this, but spring does not officially begin until the equinox on March 21. So, this is a late winter walk.
This walk was near Big Sabine on Pensacola Beach. As I crossed the road at Park East and headed into the dunes there was a breeze from the south creating surf that could be heard across the island. The fog made things damp and chilled. And there was no sign of wildlife anywhere. The numerous songbirds I had encountered during early and mid-winter were gone. There were flowers in bloom but no insects pollinating them. Literally no wildlife was to be seen.
A foggy day on Pensacola Beach.
Photo: Rick O’Connor
So, I turned my focus to the environment, noticing plants and the stages they were in. As you move from the primary dunes of the Gulf side into the more shrub covered secondary dunes, you cross through low areas in the dune field called swales. Here water collects during rain events forming ephemeral ponds and the plants associated with this habitat are more wetland than upland. In the boggy portions of the swale, I found sundews large and in a brilliant red color. These carnivorous plants produce tiny droplets of sugar water on threads at the tips of their leaves that attract the pollinators of the beach. Though sweet and delicious, they are also sticky and trap unaware insects which become a meal for them. Along with the sundew were numerous strands of ground pine, another carnivorous plant of the swale.
Swales are low areas of the dune field where water stands for periods of time and the more wetland plants can exist.
Photo: Rick O’ConnorThe carnivorous sundew inhabits more wetland locations.
Photo: Rick O’Connor
Beyond the swale, the secondary dunes were a blanket of lavender. The false rosemary, also called beach heather (Conradina), was in full bloom everywhere. As I walked through the dunes of flowers I came across the signs of wildlife. Armadillo dens were quite common. There were tracks of animals, including the raccoon, and scat was found. The scat contained seeds and, unlike the long-tapered shape of most carnivore scat, was blunt and rectangular shaped – suggesting a herbivore or omnivore. I did encounter a couple of ephemeral ponds with very little water, but there were no animals, or animal sign, to be found there.
The false rosemary was in bloom and the dunes were full of this lavender color.
Photo: Rick O’ConnorArmadillo burrows like this one can be found all over our barrier islands.
Photo: Rick O’ConnorThe blunt ended and rectangular shape of this scat suggests it was from a herbivore or omnivore. It was full of seeds.
Photo: Rick O’Connor
As you move from the secondary dunes into the maritime forest you pick up a section of the Florida Trail. This 1,500-mile trail begins at Ft. Pickens on the western end of Santa Rosa Island and ends near the Everglades. It was obvious that many of the animals who live in these dunes use this trail as well, there were numerous tracks covering it. Over the ridge into the maritime forest, you encounter marshes. The plants you find growing there help indicate whether the marsh is fresh or salt water. Pausing here to see if something stirred or moved, I saw and heard nothing and continued on.
The orange blaze indicates this is part of the Florida Trail.
Photo: Rick O’Connor
The maritime forest was full of healthy pine and oak trees, creating a completely different habitat for the wildlife out here. You get the feeling when you enter the forest that this is where the creatures prefer to be. Raccoons, skunks, coyote, snakes, birds, lizards, exist here and I was hoping to find something. And then it happened. Glancing up into one of the pine trees I saw a great horned owl – bingo! These are amazing birds and there have been a few reports of nesting great horned owls around the area. I did not see the nest but was happy to see the owl.
The maritime forests of our barrier islands is a completely different environment than the open dune fields.
Photo: Rick O’ConnorUsing the nests of other raptors, great horned owls raise their young this time of year. This one is in the “extended” position suggesting it is alarmed.
Photo: Rick O’Connor
I eventually reached the shore of Santa Rosa Sound and walked along for half a mile or so. I did see a great blue heron in the marsh, and some wharf crabs under a plank of wood – but there was nothing visible in the clear water of the Sound. There was evidence of armadillos digging. One section of the beach they had basically destroyed digging for grubs and other invertebrates to eat.
All in all, it was a quiet day. I am guessing that the foggy conditions moved the animals into their hiding places waiting for the sun to come out. Our next walk will be in early spring, and we are hoping to see more wildlife.
You should get out and take a hike on our beaches, there are plenty of cool things to see and it’s great for your mind.
Six months ago, they were predicting a colder than normal winter. In January that seemed to be the case. We had multiple fronts with high winds and temperatures dropping into the 20s. But February has been different. As I type this, it is 62°F and we have had some of the nicest days we have had in a while. Sunny, low humidity, really nice. AND THE GROUNDHOG SAW HIS SHADOW!!! So… maybe an early spring?
With the warmer temperatures I thought we might encounter some of our ectothermic friends (amphibians and reptiles). On days like we have seen, snakes and turtles will come out from their winter hiding spots to bask in the sun. Since our early winter article, two cottonmouths have been seen on Santa Rosa Island. They were both reported as being very sluggish – but that is to be expected – it is still winter, and the temperatures are still low in the mornings. With that thought in mind we did our February mid-winter hike at Ft. Pickens.
A cottonmouth found on the trail near Ft. Pickens. Photo: Ricky Stackhouse
The hike was on February 6. It was a beautiful sunny day, the temperature was 49°F, light wind from the north. I will say, in the wind it was a bit chilly, but behind the dunes it was very pleasant.
Along the trail I noticed a lot of green plants, but nothing was in bloom. Often the change in temperature can fool flowering plants into blooming early. However, the pine trees were full of male and female cones. They were definitely getting ready for pollen season.
The female cone of a pine tree.
Photo: Rick O’ConnorThe male cones of this pine tree are releasing the all too familiar yellow dust pollen.
Photo: Rick O’Connor
I began in the middle of the island in the hardwoods, moving slowly hoping to find a basking snake. I did not, but I did see numerous woodland songbirds. I am not a good birder, but I believe there were varieties of warblers, titmice, wrens, and the always present mockingbird. I did spot a great blue heron on a nest. Birds are endothermic – and this is their time – a great time to do some birding if you like that.
Blue herons often use the tops of pine trees for nesting.
Photo: Rick O’Connor
I took another trail heading towards the beach. This crossed through more woodlands before reaching the dunes and the shore. It was in the woodland area I came across a bald eagle nest. Many of us remember a time when we never saw bald eagles around here. Now they are becoming more common and nesting all around the bay area. These awesome birds are similar to dolphins, sea turtles, manatees, and the Blue Angels – you never get tired of seeing them. It is always an exciting moment when one flies over.
The American bald eagle.
Photo: Rick O’Connor
There was no wildlife on the beach that day but there were plenty of tracks. Mammals, even in the winter, still prefer to move around under the cover of darkness. I found the tracks of armadillo and raccoon, common mammals on our island, but there was another set that was harder to identify. The paw had the imprint of a cat (no claws visible) but the track was quite large for a feral cat. If it was, it was a big cat. I have seen bobcats in the Gulf Breeze area, and you cannot rule them out, but the pattern of the stride appeared more like an otter. Otter tracks would be webbed – these were not – so… I am not sure what it was.
Most encounter island mammals by finding their tracks.
Photo: Rick O’Connor
Leaving the beach, I returned to the inland trail heading back to the truck. On this portion of the trail, you cross over ponds just outside the walls of the fort. As I glanced across the water – hoping for a swimming snake – I saw something else. It surfaced briefly and then dove again. At first, I thought it was a diving bird, such as a cormorant or loon, but when it resurfaced, I saw that it was not. It was an otter. I had seen otters before in this area, and other pond areas on the island, but – like the bald eagle and dolphin – it is always exciting to see them again.
Based on this hike, it is still the time of the “warm-blooded”. Birds and mammals were the creatures most visible. We will see if this warming trend continues. Maybe during the late winter hike in March, we will see some of the “cold-bloods” come out. Maybe it WILL be an early spring.
No one species has altered the land, sea, and sky – as well as decreased the overall biodiversity of the planet in such as short time as has Homo sapien. Since we have arrived on this planet we have slowly dispersed across all continents, oceans, and even the polar regions. In our wake we have changed the landscape. Altering forests and changing waterways. We have built communities and cities and, in recent years, increased the amount of waste we produce to impact the land, water, and even change the climate. Our planet has encountered major changes in climate and habitats before – but not at the rate it is currently happening, and many are not able to adapt fast enough. Wildlife over much of the planet has declined due to our activities – and barrier islands are not an exception.
Humans have found our barrier islands. Photo credit: Lydia Weaver
Humans first arrived in the Florida panhandle a little over 10,000 years ago. Most of them built communities along our riverways and deltas. As with much of coastal wildlife, barrier islands were difficult places to inhabit. There is little freshwater, selected game to hunt (though an abundance of seafood – which they did seek), intense heat in the summer and cold in the winter, and tropical storms – where there were few places to hide. It appears humans did visit the islands but did not settle there. The early European colonists tried, but unsuccessfully – they had to moved inland.
In the Pensacola Bay area, the first settlements that were successful were fortifications placed there by the U.S. Army to protect the communities where people lived. These were brick fortifications that held up well against the storms, all built with large cisterns to collect freshwater for the troops stationed there. Soldiers accessed them using ferries.
In the early 20th century locals from Pensacola built a casino at what is now Pensacola Beach. There were casinos, boxing, and food vendors for those who made the day trip by ferry to visit the location.
The famous “beach ball” of Pensacola Beach marks the spot where the old casino once stood.
Photo: Molly O’Connor
Much of this early human activity had little impact on the island wildlife. Humans were concentrated in specific locations and did not / could not venture very far from them. But when automobiles became more commonplace with people, bridges soon followed, and things did begin to change. More cars meant more people, and the need for roads. These roads bisected the dune system and altered how they naturally progressed with wind and waves. Not only did dune dynamics change but dunes began to disappear with the new homes and hotels that were built.
A coyote navigates the roads that are now on our islands.
Photo provided by Shelley Johnson.
Homes, cars, and roads made life for several island creatures tough. Most of the shorebirds using the islands as nesting areas lay their nests on the sand. The white/speckled eggs blend in well with the white sand and the warm sand helped incubate them. There were fewer predators on these beaches and so, protection of the chicks was achieved more by driving off any potential threat by “dive bombing” them. This did not work with humans, nor their cars. The roads became hazards for them, and small chicks were often hit by cars. Today some species are threatened and have been given federal protection.
A variety of shorebirds utilize the sand as a nesting area.
Photo: Rick O’Connor
In recent years beaches houses have become true homes, with lawns and gardens. This alters the natural landscape even more. Along with the altering of the dune systems, this impacted many dune creatures like the beach mice. The species on Perdido Key is now considered endangered, and also has federal protection.
Additional housing, development, and roads led to additional needs in lighting in the evening. Many barrier island creatures need “dark skies,” but notably are the nesting sea turtles. In recent years 50-60% of sea turtle nests on our islands have had adults and hatchlings “disorient” towards the artificial lighting instead of the moon/star light that reflects off of the Gulf. This, along with other human related impacts like structures left in the sand at night, have caused a decline in these turtles and they too are now federal protected.
Turtle friendly lighting.
Photo: Rick O’Connor
You could not mention impacts by the human presence without mentioning solid waste – marine debris. Modern humans produce a wide variety of plastic products which we bring to the beach, and some of it ends up in the environment. Sea turtles, shore birds, and even manatees have been found either entangled in it or having ingested it. Much of this marine debris is problematic for the wildlife there.
Boxes providing garbage bags and disposal.
Photo: Pensacola Beach Advocates
Recently there has been an increased issue of pet cats that are allowed to roam the island at night. These pets (some strays) are known for the impact they can have on small wildlife like birds.
We were lucky in Escambia County during the 1970s to have the National Park purchase about 50% of the island as a National Seashore. This has provided a space for the island creatures and a great nature/cultural tourism destination.
Much of the west end of Santa Rosa Island has remained natural due to the presence of the Gulf Islands National Seashore.
Photo: Molly O’Connor
No one moves to the beach with the intent of harming wildlife, but our sense of changing things when we arrive – which we have been doing for some time – does impact them. The answer to this problem is to learn how to live, and develop, with the wildlife on the islands. The islands play a crucial role in protecting the mainland from storms and providing habitat for several unique species. Many of these species are beneficial to our lives by playing an ecological role in maintaining the island. It can be done.
I hope you have learned something new in this nine-part series on barrier island wildlife. If you have, please let me know by emailing roc1@ufl.edu. I hope you get a chance to explore our islands and maybe see some of these neat creatures.
The definition of an invasive species used by the University of Florida IFAS has three parts.
It is not native to the area.
Was brought to the area by humans; either intentionally or accidentally.
Is causing an environmental or economic problem, or somehow lower the community’s quality of life.
Florida is famous for its invasive species problems. Actually, every state in the country is battling this issue. In 2005 the estimated economic cost of invasive species in the United States was $137 billion annually. Looking at the Invasive Species Curve (below) you can see the most effective method of managing is to prevent them from coming in the first place. Easier said than done. International travel and commerce by plane and boat enters Florida every day, who knows what these are bringing with them. There is the legal trade, illegal trade, and the accidental hitchhiker. Though there are efforts in each state trying to prevent invasive species from entering, they do enter. Once they have arrived, resource managers move into what we call Early Detection Rapid Response (EDRR) in hopes of eradicating the species but at the very least containing them. It is a constant battle.
The Invasive Species Curve
Though separated from the mainland, our barrier islands are not immune to this threat. Humans travel to and from our islands all year round; we live on many of them. With us comes non-native species we both intentionally and accidentally bring. Some of these become invasive and can threated the wildlife of our islands. The state is divided into 15 Cooperative Invasive Species Management Areas (CISMAs). The western panhandle is under the Six Rivers CISMA, the eastern panhandle is under the Apalachicola Regional Steward Alliance (ARSA). Both CISMAs have developed a EDRR list for their area. As a member of the Six Rivers CISMA, I helped developed ours and below are the species considered the biggest threats to our island wildlife.
Florida CISMAs
Beach vitex (Vitex rotundifolia)
Beach vitex is native to the Pacific coast of Asia and was intentionally brought to the United States as an ornamental/landscape plant. It does well in open sunny areas, dry soils, along the coast – perfect for barrier islands. In the 1980s it was used for dune restoration in the Carolinas and that is when its invasive nature was first seen. Like all invasive species, there are few predators and disease, and so reproductive success is high. The species multiples and spreads rapidly, basically uncontrolled. Beach vitex is allelopathic, meaning that it creates an environment that can kill nearby plants and thus take over that area; sea oats are one species this occurs with. Its impact on wildlife could include the loss of required habitat and food source. It appears to have already impacted sea turtle nesting in the Carolina’s, and that threat exist here as well. It could also impact the ecology of the listed beach mouse.
I was first made aware of the presence of this plant in the Pensacola area in 2013. It was discovered on the shoreline of a private property on the Gulf Breeze peninsula in Santa Rosa County. It was suspected to have come from nearby Santa Rosa Island. A survey of the Pensacola Beach area found 22 sites where the plant existed. One was quite large, covering about 70% of the property. The others were small individual plants. Some were part of a homeowner’s landscape; others were on public land. At the time, beach vitex was not listed as an invasive species in Florida. Today it is and has also been declared a state noxious weed. A database search indicates there are currently 118 records in the state of Florida found in six counties. Four of those counties are in the Florida panhandle and include Escambia, Santa Rosa, Okaloosa, and Franklin. More in-depth surveys of the coastal areas, and islands, of the remaining counties in the panhandle may find more records of the plant. There are active projects in the Escambia/Santa Rosa area to manage it.
This yard on Pensacola Beach has become over run by vitex.
Cogongrass (Imperata cylindrica)
Cogongrass is native to Central and South America. It was brought to the United States accidentally through the Port of Mobile. It quickly spread across the landscape covering much of south Alabama, northwest Florida, and Mississippi. It now can be found in most of Alabama, a large portion of Mississippi, much of Louisiana and Georgia, some of the Carolina’s, Tennessee, and Virginia, and in every county of Florida. It is not only listed as an invasive species in these states, but also as one of the nation’s worst noxious weeds. It quickly covers pastureland. Being serrated and having silica with the grass blades it is not palatable to livestock, you can lose good pastureland when this invades. In natural areas and private timberland, it quickly covers the understory where it burns too hot during prescribed burning efforts and creates a situation where the valuable management method cannot be used. It is not a good plant to have on your land.
In 2020 we were made aware the plant was growing on Perdido Key in Escambia County. We are not sure how it got there but most likely from landscaping equipment that was not cleaned after working an inland area where the plant was present – this is a common method of dispersing the plant. Currently there are 456 records along the coast of the Florida panhandle. 404 of these are on coastal beaches and 52 are on our barrier islands. 44 of the island records are on Santa Rosa/Okaloosa Island, 4 at St. Andrew’s State Park, 1 on Cape Sand Blas, and 1 on St. Vincent Island.
What impact this plant will have on barrier island wildlife is not fully understood. But we know that it has not been beneficial within inland habitats and the potential of having a negative impact is there. Locally we will begin to survey for exact locations on the islands in Escambia County in 2023 and begin a management plan for those, as well as education outreach to reduce potential sources.
Cogongrass shown here with seedheads – more typically seen in the spring. If you suspect you have cogongrass in or around your food plots please consult your UF/IFAS Extension Agent how control options.
Photo credit: Mark Mauldin
Giant Salvinia (Salvinia molesta)
This is a new invasive species to our area and, until recently, was only found within our state in the panhandle. There are now 19 records found in 7 counties across the state; 10 of the 19 records are in Escambia County. This is a freshwater species that prefers quiet backwaters with high levels of nutrients. In our county the plant is concentrated in the upper arms of Bayou Chico. Though an estuary, Bayou Chico has relatively lower salinities than most of our other bayous – the plant is doing well there. The Florida Fish and Wildlife Conservation Commission (FWC) began management of this area a few years ago, but it is still there and seems to have spread to a nearby retention pond. The best guess as to method of dispersal were beavers seen moving back and forth between the water bodies. We plan to conduct surveys of other nearby retention ponds in 2023.
Though relatively new to Florida, it has had a large impact on the freshwater systems of Texas and Louisiana. I witnessed firsthand that impact at a lake near Shreveport LA where I was camping. This plant is a small one that floats on the surface of the water. It resembles duckweed but the leaves are larger. It had completely covered the surface of the lake and was kept out of the swimming area by using booms. There was no way to fish in the lake and moving through with a paddle craft would have been difficult. It is similar to water hyacinth covered waters. Though the swimming area was clear, the bottom had become “mucky”, and no one was swimming. All water recreation had stopped. The thick canopy covering the surface of the lake blocks sunlight so no submerged grasses can grow, the dead plant material decomposes and draws down the dissolved oxygen levels which could create fish kills.
Knowing this, FWC has a team focused on eradicating this plant from our state before such situations occur here. Though it will not reach our barrier islands by floating there (because of its dislike of salt water) if it DID reach any of the retention ponds near the homes, hotels, and condos, via landscaping equipment used on inland ponds, or some other method, it could be a real problem. And, as we have seen in Bayou Chico, wildlife could move it to the natural freshwater ponds on the island. We will begin surveys of all ponds on Perdido Key and Santa Rosa Island in 2023.
Giant Salvinia mats completely covering Bay County pond. This fast growing invasive can double in coverage every two weeks! Photo by L. Scott Jackson
The Brown Anole (Anolis sageri)
This small lizard from Cuba (also known as the Cuban anole) has been in Florida for some time. It most likely reached our shores accidentally by hitchhiking on a boat. With south Florida’s tropical climate, the lizard did quite well and began to disperse north.
I first encountered the creature on campus in Gainesville. Along west side of Ben Hill Griffin Stadium (The Swamp) are trees that are enclosed in wooden boxes – a sort “raised bed” look. When I looked in one of them there were numerous brown lizards scattering everywhere. I checked the next tree and found the same. I found the same in each of the tree boxes along that road. I then began to see them at the rest stops on I-10 between Pensacola and Gainesville. You would step out of the car and as you walked you would see numerous small brown lizards scattering everywhere. The same ones as in Gainesville – the brown anole. I then received a call from a resident on Innerarity Point Road near Perdido Key. She wanted to know what type of lizard she was now seeing in her yard. They were small, brown, had white spots (diamond-like patterns) on their backs and were EVERYWHERE. I asked for a photo, and eventually made a site visit, they were the brown anole. I then began to receive calls from other residents near Perdido Key, then from Gulf Breeze, then from the East Hill area of Pensacola. All the same. The brown anole had made it to Pensacola. Interestingly, when I was speaking to a garden club about invasive species, and was discussing this one, residents from the north end of the county had no idea what I was talking about. They had never seen them. They apparently were invading near the coast. Between 2018-2021 I was conducting a cottonmouth survey on Perdido Key for a Homeowners Association who was encountering a lot of them. At first the brown anoles were not there. Then, during the second year of surveying, I began to see them. The brown anole had reached the barrier island.
It is believed that the mode of dispersal is the same as how they reached Florida in the first place – hitchhiking. Most likely on landscape plants that were grown in south Florida, transported up here, and delivered to you. It is not quite clear how they may impact barrier island wildlife. We know where they show up the native green anole (Anolis carolinensis) begins to decline. Some studies show that the green anoles move higher up in the trees and shrubs where needed resources are limited, and the population will most likely not survive. I have watched green and brown anoles battle it out on my front porch (yes – I have brown anoles in my yard also). I have seen green anoles win these battles – but they seem to have lost the war. I seldom find them anymore. What changes may happen to wildlife on the barrier islands we will learn with time. Though I have not personally seen one on Santa Rosa Island, I am sure they are there – and probably on your barrier island also.
Cuban Anole. Photo credit: Dr. Steve A. Johnson, University of Florida
Cuban Treefrog (Osteopilus septentrionalis)
As with the brown anole, it is believed the Cuban treefrog reached our state hitchhiking on a boat. They too have been in the state for quite some time. But records in the Florida panhandle were non-existent. It was believed that the winters here too cold for them. But that appears to be changing.
I have had occasional calls about this frog over the last few years. In each case it was a single individual, hanging on their windows and glass doors, shortly after the homeowner had purchased new plants for landscaping. As with the brown anole, we believe this is a common method for spreading them. But as we mentioned, there was not much concern because our cold winters would keep this invasion at bay. Then there was a report of several Cuban treefrogs at a location on Tyndall AFB in Panama City. They appeared to be breeding and also appeared that they had overwintered. Dr. Steve Johnson (of the University of Florida) later confirmed this to be the first recorded breeding group in the panhandle. And the “love had begun to spread”. More accounts were being reported in the western panhandle. One community in Santa Rosa County found over 100 over the course of a year. Again, we think they are spreading with landscaping plants, or hitchhiking by other methods.
The issue with the animal is similar to that of the brown anole. It is much larger than our native treefrogs and likes to devour them. They are large enough to eat small native lizards and snakes as well. They produce a mild toxin in their skin that can irritate your eyes, nose, and even trigger asthmatic attacks. They have been found in toilets and are known to even plug the plumbing. They have also been found in electrical power boxes and have caused power outages. Overall, they are pain to deal with.
There are currently 28 records in the Florida panhandle. Though some have been found along the coast of our estuaries, there have been no reports on our barrier islands. Maybe we can educate the public on the hitchhiking issue and possibly keep them off the islands. We will be initiating a citizen science effort to monitor their locations on Pensacola Beach and Perdido Key beginning in 2023.
Cuban Treefrog.
Photo by: Dr. Steve Johnson
Invasive species, by definition, are a problem for barrier island wildlife. But another problem they are facing is the increase in humans. That will be the topic in part 9.
The land of the wet and muddy – that’s what lot of folks call the salt marsh. If you have ever experienced walking through one you know why they call it that. Salt marshes are wetlands that are dominated by grasses and are partially flooded with salt water during high tide; some portions of the marsh are still flooded at low tide. The grasses that grow there are halophytes (salt tolerant). Their diversity is low, but abundance is high.
Salt marshes are wetlands dominated by grass.
Photo: Molly O’Connor
Salt marshes grow on the protected side of the island – the bay side – and even there they do better in protective coves and inlets off of the main shoreline. They are not big fans of high wave energy. The grasses that live there are spaced in zones. Smooth cordgrass (Spartina) is more water and salt tolerant than black needlerush (Juncus) and is found along the marsh edge close to the shore of the bay itself. Black needlerush dominates the upper marsh closer to the maritime forest and tertiary dunes.
If you approach the marsh from the dune/forest side, you will encounter a dense field of needlerush. As you step into it you will experience soupy layers of black mud and detritus. Your feet sink and, if you do not have on secured shoes, you will lose them. You will get the odor of rotten eggs as you walk. This is hydrogen sulfide released by bacteria who are decomposing the leaf litter, and other organic matter, that is trapped and collected with the rising and falling tide. There is not a lot of wildlife in this area. The mud is deep, and the food sources are few. You will notice small white snails on the needlerush blades. These are marsh periwinkles. During high tide they move up the grass blades to avoid predators, at low tide they come down to feed on the organic material on the exposed mud.
Eventually you find small creeks heading towards the bay. Here the water is murky and the bottom still very muddy. Scattered amongst the needlerush are mounds of high dry ground covered in salt bush (Baccharis) where some animals can move around much better. Raccoons frequently these small “islands” seeking the numerous fish and shellfish that can be found in the creeks. Ribbed mussels can be found attached the base of the needlerush and are a particular favorite of the raccoons. Juvenile blue crabs can be found scavenging food sources in the creeks, juvenile mullet is common, as are small killifish and mollies. These can provide food for wading birds like the great blue heron who has widespread feet that resist sinking in the mud and allow them to hunt. Sometimes oysters and crown conchs are found in the creeks. Oysters do not move and cement to each other forming clumps. They filter feed in the water column collecting organic material and improving the water clarity – unless you walk through and sir up the mud and silt.
A creek within a salt marsh on Santa Rosa Island. The water here is saline, particularly during high tide. Photo: Rick O’Connor
These small creeks become wider and deeper as you approach the bay. In places the bottom becomes sandier, and all of this allows other species to forage. The above mentioned are still present. Oyster clumps become more numerous because they are not covered by the silt of the upper marsh. In the sandier areas flounder can be found feeding on the small fish and shrimp that reside here. This part of the marsh can be an important nursery for many open estuarine species. A variety of shrimp are found here, crabs, and juvenile fish as well. With more sand it is easier for herons to walk and hunt.
This little blue heron is stalking prey in a Gulf coast salt marsh.
Photo: Molly O’Connor
There are also a few reptiles found here. The American alligator can be found at times, but are more common in the open lagoons. The Gulf salt marsh snake (Nerodia) resides here. They are nocturnal and rarely seen. But in the spring when breeding is going on, they can be encountered during daylight hours. These are none venomous snakes.
The nonvenomous Gulf Salt marsh Snake.
Photo: Molly O’Connor
Interestingly the venomous cottonmouth can be found here. This is an interesting story. The cottonmouth is associated with freshwater. It is not surprising, or uncommon, to find them near the freshwater ponds we have discussed already. By they do not have the lachrymal glands found in sea turtles and terrapins that allow them to swallow seawater, excrete the salt through glands in their eyes, and use this as a freshwater source. It appears that the cottonmouth needs freshwater for drinking. Despite this they are being encountered more often in more saline areas. One barrier island near Cedar Key, Seahorse Key, supports a large population of cottonmouths. It has been stated there may be more per square meter there than anywhere in Florida – and there is no source of freshwater. Researchers from the University of Florida have found they drink from pools of freshwater that form after heavy rains and are very opportunistic when it comes to selecting prey – including other cottonmouths. The species found on Seahorse Key is Agkistrodon conanti (Florida Cottonmouth). The eastern cottonmouth (A. piscivorous) is the one most common in and around our freshwater systems. It would be interesting to determine which species is living on our barrier islands, and how they use the landscape. Though I have never seen them swimming in the larger creeks of the marsh, I have seen them basking along its edges many times. I am sure they use this saline environment.
This cottonmouth is basking in a salt marsh on Perdido Key.
Photo: Jen Aicher
Another unique marsh reptile is the turtle known as the diamondback terrapin. This is the only resident estuarine turtle in the United States. They are related to the freshwater pond turtles people frequently see but prefer the more saline marshes of these islands. They feed primarily on shellfish and have a preference for the marsh periwinkle snails that climb the grass blades.
River otters have been found swimming in these large creeks searching for food. They seem to like both fish and shellfish. Redfish can be found in the wider deeper creeks. The mullet and flounder found here are larger.
Hermit crabs are abundant here. These are crabs whose abdomens are not covered by shell. So, they must seek abandoned mollusk snails to “hide their rears”. They will select any shell but seem to prefer oyster drill and moon snail shells – possibly because they are more abundant. Oyster drills are snails who use their serrated tooth (a radula) for “drilling” into oyster and consuming them. Crown conchs and ribbed mussels are abundant here.
The shell of the oyster drill.
Photo: Rick O’Connor
These larger creeks sometimes feed directly into the bay, but sometimes they feed into a large open lagoon. These lagoons are full of fish. Mullet, redfish, flounder, stingrays, pinfish, and – if deep enough – even small sharks can be found here. Wading birds, like herons and egrets, and common along the shorelines and diving birds, like osprey and pelicans, are found here. The shoreline near the grasses still has small juvenile fish. The sandy beaches can support the hunting of raccoons and armadillo tracks are common. The alligator encounters I have had are more common here and we often see the heads of terrapins. The river otters I have seen here are usually along the edges.
The open lagoon of the salt marsh. Photo credit: Erik Lovestrand, UF IFAS
Another unique marsh critter is the fiddler crab. Though found throughout the marsh, they seem to be more abundant where there is more sand. Related to the ghost crab of the Gulf side, these small crabs dig burrows down to the water table. When the tide is high, they plug their burrows with mud and sand, then wait. When low tide arrives they emerge in the thousands to scavenge the shoreline for organic material in the sand – forming these round balls of sand as they are cleaning it that I call “coco-puffs”.
All large creeks and lagoons are connected to the open bays of the northern Gulf of Mexico where seagrass meadows form. As you walk the north shores of panhandle barrier islands you find sandy beaches often loosely covered by a variety of grasses. Walking inland you again return to either the tertiary dunes or maritime forest and may be another salt marsh. You have now experienced the primary habitats, and wildlife found within, on our barrier islands. But there are new concerns that could alter the ecology of these systems. One of those are invasive species. We will discuss this one in Part 8.
