Stories of the Swamp

Armchair Interpretive Walks

Friends of Fakahatchee: Dedicated to financial and volunteer support to preserve the unique ecology and cultural heritage of Fakahatchee Strand Preserve State Park and educate the public about its importance.

Mosquito fish – Our Unsung Heroes

by Patrick Higgins

Mosquito Fish

A female Eastern Mosquito Fish (Gambusia holbrooki). Photo by Patrick Higgins.

I’m often privileged to take people into the Fakahatchee for their very first swamp walk. It’s nearly always a transformative experience for them. After marveling about the dappled light, oohing over the epiphytes, commenting on the clarity of the water, the fresh minty smell and how surprisingly firm the footing is, they often quizzically remark “but there are no bugs.” Well, that is if you take them to the right place at the right time of the year. And if the mosquito fish are dong their job.

By bugs of course they mean mosquitoes and so, on cue, I can launch into a talk about those little two-winged flies and their nemesis, the humble mosquito fish. As Floridians we can be very proud; we have over 80 species of mosquitoes. That’s more than any other state. These can be divided these into two broad groups; floodwater and standing water mosquitoes.

Floodwater mosquitoes, like our particularly vicious black salt marsh mosquito (Aedes taeniorhynchus), don’t lay their eggs in water. Instead they seek out moist ground. The eggs need to dry out before they hatch and lay dormant in mud cracks and crevices. When they are inundated by heavy rains, or in the upper reaches of our salt marshes, monthly by spring tides, they quickly develop. The density of mosquito eggs in a floodwater habitat can be staggering, as high as 1.3 million per acre.

All but 3 other species of our ‘swamp angels’ are standing water mosquitoes that lay their eggs in water. They cannot withstand drying out and usually hatch within 24 hours. Fortunately in both categories it’s only the females that need a blood meal as a protein source for egg development. The males typically feed on nectar. Think what it would be like otherwise.

In a perfect model mosquitoes should only be a problem at the beginning and end of the dry season when there are isolated pockets of water that our native mosquito fish cannot reach. But it’s not as simple as that, because sometimes the rains don’t follow our seasonal model. Last summer was a classic example. The rains started in a timely manner in June, but kind of stopped in July, then came back with a vengeance in September. I was reconnoitering a potential new swamp walk off South Main a few weeks after this occurred, and the mosquitoes were so bad I couldn’t escape soon enough.

We’d had repeated deluges that had flooded the dry swamp landscape, triggering floodwater eggs and creating habitat for standing water mosquitoes to breed. And breed they did at a much faster rate than their vertebrate predator, the mosquito fish. This created a lag, which if you plotted on graph paper would show a classic bell curve as the mosquito population surged, then a rapid decline as the mosquito fish population multiplied and spread across the newly created aquatic landscape. Eventually we reached a nice equilibrium for our swamp walk season.

Mosquito fish

An egret’s eye view of our native Mosquito Fish. Photo by Patrick Higgins.

So our unsung hero in all this is the Eastern Mosquito fish (Gambusia holbrooki). The females are about 2 ½ inches long, and the males are about an inch shorter. Gambusia are viviparous – they bear live young, which enhances their survival probability. In nature the quantity of offspring is usually inversely related to the chances of any individual reaching maturity and reproducing. So, for example, when a female cod spawns she lays hundreds of thousands of eggs. A mosquito fish typically only gives birth to 25 live young, but can do this up to nine times a season. These young reach sexual maturity in 4-6 weeks. They are technically planktivores, but are voracious predators of mosquito larvae when available. A large female can consume hundreds a day.

But here’s the rub, as demonstrated by a remark made to me on a recent tram tour –  “We should get some of those and take them up to Michigan.” That’s exactly what has been done all over the world. The problem is that they have co-evolved here in a highly competitive environment where they’ve had to eke out a specialized niche. When they are introduced to non-native waters they tend to prey heavily on the eggs and young of other fish species – perhaps the very ones that ate mosquito larvae there. So if you search the literature on mosquito fish, you’ll find most of it is about how to get rid of them where they have been introduced.

Incidentally a British biotech firm is in the late stages of FDA approval for a trial release of genetically modified male Aedes aegypti mosquitoes here in Florida. The idea is to help control the spread of Zika and dengue fever. They have been engineered to pass on a ‘kill-switch’ gene when they mate with our wild females. This prevents their offspring reaching maturity. Trials in other countries have reduced the target Aedes population by more than 90 per cent, but I’m not sure the locals in Key Haven, the chosen test site, will go for it so we’ll just have to rely on our Gambusia.

Patrick Higgins with an apple snail. Photo by Robert Fisher.

Patrick Higgins with an apple snail. Photo by Robert Fisher.

Patrick Higgins is a National Association of Interpretation Certified Interpreter, Vice-President of the Friends of Fakahatchee and Project Manager for the development of the Boardwalk Master Interpretive Plan.

Mollusking in the Fakahatchee – Part 1

By Patrick Higgins

As I was recently stalking through one of Fakahatchee’s sloughs, I found myself fantasizing that I was a great big wading bird. It seemed perfectly natural to move ponderously so as not to create a ripple in the golden water. I slid each foot forward in slow motion, conscious of everything around me: the Sun streaming through a leafless winter canopy, a single red maple leaf floating by, a movement in the cutgrass to my left, the rustle of an anhinga taking flight ahead, the plop of a frog into the water. I froze as my eye caught something shimmering on the dark bottom. And then, fortunately just before I plunged the imaginary spear-like bill on my face into the water, I shook myself out of my revelry.

A handful of Florida shiny spike (Elliptio buckleyi) freshwater mussels shells fished up from one of Fakahatchee’s sloughs. They can grow up to 100 mm (3.9”) The neatly chiselled holes look like the work of a limpkin. Photo by Patrick Higgins.

A handful of Florida shiny spike (Elliptio buckleyi) freshwater mussels shells fished up from one of Fakahatchee’s sloughs. They can grow up to 100 mm (3.9”) The neatly chiselled holes look like the work of a limpkin. Photo by Patrick Higgins.

Instead I fished down clumsily with my hands, wetting my sleeves in the process. I had to feel around a bit due to refraction, but finally my fingers closed around my target. It was the fragment of a bivalve’s shell and shone like burnished silver. When we think of swamp invertebrates our minds tend immediately to go to crayfish, insects, snails and such, but we seldom give much thought to the snail’s mollusk cousin: the freshwater mussel.

After a bit more probing I was able to come up with a whole shell, although it was empty. Its ebony exterior was striated by growth rings, some of which had eroded revealing the iridescent mother-of-pearl beneath. In the center was a neatly chiselled rectangular opening, probably the work of a limpkin’s bill.

This is the same mother-of-pearl that was used for over half century in button production until plastic came into being in the 1940’s. Today ground freshwater mussel shell is still favoured as a seed material for Japan’s cultured pearl industry.

However, freshwater mussels are not simply freshwater versions of the marine mussels we love to eat cooked with butter and garlic and washed down with a glass of white wine. True, they both are aquatic filter feeders, sort of resemble each other by having asymmetrical shells that are longer than wide, and are both bivalves, but freshwater mussels are members of an entirely different subclass (Palaeoheterodonta). In fact, marine mussels are more closely related to oysters and scallops than they are to their freshwater namesakes.

The biggest difference is in their life cycles. Marine mussels are sessile. They typically attach themselves in clumps with those stringy byssal threads we scrape off when preparing them for the pot. They reproduce by releasing sperms and eggs into the water in a rather hit or miss fertilization process. They then go through a floating planktonic stage before settling out of the water column to live in a fixed location.

On the other hand, freshwater male mussels release gametes into the water column. The gametes are then sucked into a female’s siphon, where her eggs are fertilized internally. The fertilized eggs develop in specialized brood chambers in her gills into tiny motile glochidia. This specialized larval form has an array of hooks, which allow them to attach to fish where they live as parasites for a period.

Many species are highly host specific. Some mussels even use mimicry to lure in host fish by packaging their glochidia to look like prey items such as fish eggs or insect larvae. Typically the glochidia attach to the fish’s gills, although some species also utilize the tail fins. This is an important adaptation to aid distribution. Otherwise, in freshwater streams and rivers distribution would be one in direction only, i.e. downstream. After a few weeks feeding on the host fish they complete their metamorphosis into juvenile mussels, then detach and fall to the bottom to begin their adult stage.

This is where a second huge difference comes in. Freshwater mussels have a powerful clam-like foot which enables them, through a series of muscular contractions and expansions to burrow, anchor themselves or move along the bottom. They seldom move more than a few hundred feet, but that could be critical to survival as water levels drop. Finally, they are known for their longevity. Some species live up to a hundred years.

The mussel I was holding in my hand appeared to be a Florida shiny spike (Elliptio buckleyi or to some taxonomists E. jayensis) – one of 365 North American, 62 Floridian and 14 lower-peninsula species. I say probably because many freshwater mussels are incredibly hard to identify without the aid of magnification.

The same species from different habitats often have variations in shell shape. There is so much speciation in freshwater mussels due to their intolerance to saltwater. This inhibits spreading from one river basin to another, isolating populations. It is therefore not surprising that 69% of Florida’s freshwater mussels are endemic, some to specific catchment areas.

To date, three host fish species have been identified for Florida shiny spike’s glochidia. These are Bluegill, Largemouth Bass and the Florida Gar, but in the incredible web of life about 40% of shiny spikes are in turn parasitized by several species of mites.

Freshwater mussels provide an important ecosystem function. As filter feeders they are constantly straining bacteria, algae and particulate matter from the water column, cleansing it in the process and reducing contaminant loads. They can filter as much as of 1-2 quarts per hour depending on the bivalve’s size. Their faecal matter and ejected particulates then provide food for invertebrate communities that in turn support fish populations.

They occur in almost every freshwater habit, except highly acid rivers which inhibit shell production. However, some 60 North American and 7 Florida freshwater mussel species are listed as threatened or endangered. This is due to habitat loss or alternation such as silting or pollution. So keep a look out for those telltale glittering fragments of mussel shells next time you’re in the swamp.

Oh, one final difference between marine and freshwater mussels: they are a prized food source of raccoons, otters, crayfish, and many wading birds. Also, they were consumed by Native Americans after much boiling, but apparently taste like old boot – something I haven’t put to the test yet!

Patrick Higgins with an apple snail. Photo by Robert Fisher.

Patrick Higgins with an apple snail. Photo by Robert Fisher.

Patrick Higgins is a National Association of Interpretation Certified Interpreter, Vice-President of the Friends of Fakahatchee and Project Manager for the development of the Boardwalk Master Interpretive Plan.

Hammocks and Cypress Domes

by Tony Marx

Visitors to Southwest Florida are often intrigued by the undulating tree-covered backdrop which seems to comprise small hills. Most obvious as you drive along I-75 Alligator Alley, this is also evident in the Fakahatchee Strand State Park as you begin driving along the dirt-surfaced Janes Scenic Drive after leaving the paved road. Look to your right at the distant tree line and it is not level as you would expect, when viewed across the open marl prairie. Rather than a rise and fall in elevation, the dome shaped mounds of trees actually indicate a water-filled depression or solution hole under the dome. At its deepest point, the bald cypress trees grow tallest, gaining height and strength from the peat that accumulates at its deepest point. Where the trees grow around the edges of the dome, they grow shorter although they are actually the same age.

These Cypress Heads, or Domes as they are called, remain wet all year round, when the sawgrass prairie and open areas dry up and become parched during the winter and early spring Dry Season. Here alligators and wading birds collect to feed on the surviving aquatic life, and the turkey vultures gather in great numbers to feast on the left-overs. In winter, the cypress trees are bare as they annually shed their needles. These decay and, besides adding to the peat, produce acid which continues to dissolve the limestone base. Thus, the depression very slowly expands over the years.

The sub-tropical South Florida landscape, although seemingly flat, is sensitive to the slight rise and fall of elevation, when a matter of inches can promote a sharp change in scenery. The Fakahatchee Strand Preserve State Park offers an ever changing skyline. Just about all tree and plant communities found in the larger adjoining Big Cypress National Preserve and Everglades  National  Park  are found here. Where the land remains mostly unflooded, pine and palm trees replace the cypress or dense tracts of hardwoods. The ‘tree islands’ seemingly sprouting out of the open stretches of marl prairie as you drive along Tamiami Trail are also found here and one can be seen next to the road on your left about a mile along Janes Scenic Drive.

The opposite to a Cypress Dome, which sometimes looks like a tree island set in a wide expanse of sawgrass prairie, is a Cypress Head, or Hardwood Hammock. It may be a small clump of hardwoods and palms growing on a limestone ridge above the surrounding marshland. Or it may be a wider stretch of jungle vegetation dominated by Gumbo Limbo, Cabbage Palms, Oak, Mahogany, Red Maple, and others which need to remain several feet above the surrounding swamp land. As may be expected, it is home to a variety of animals, birds, and reptiles.At the center it often contains a ‘gator hole’ where alligators gather when the surrounding marsh land dries up in winter. In times of heavy rain – when the surrounding area can flood to a depth of several feet – deer, bear, and Florida panther may also take temporary refuge there.

Seen from the air or on maps, these hammocks have a distinct tear drop shape usually running north to south. They rarely flood and are often surrounded by a moat of water which keeps fires at bay. A profusion of ferns, orchids, and bromeliad adds to the jungle atmosphere. Knowing and recognizing the different tree and plant cover as you drive along Janes Scenic Drive will make your trip all the more rewarding. Deer may be seen on the open prairie, wading birds in shallow water, an owl perched silently watching for an unsuspecting rodent, a raccoon climbing a tree, and always an alligator floating lazily by or resting close to the trail. If you are really lucky, and it’s early morning or close to dusk, you may encounter a black bear or panther crossing the road or appearing ahead on the trail.

Take your time, drive slowly, and stop where safe and clear. Look down at the water, then through and up into the trees, and you will often get a pleasant surprise and a photo opportunity. Whether you see them or not, the Fakahatchee animal, reptile, and bird population is always nearby. Find a spot to park and watch quietly; one of them may appear and venture across the road or be noticed only a few feet away. Of course, a short hike along one of the marked trails is better still. Walk quietly and stop now and again to look and listen. A rustle, call, or movement will direct you to where one of our wildlife friends is going quietly about their business.

Tony Marx is a Florida Master Naturalist and former FOF Board Member. He is also a volunteer interpreter for the Fakahatchee guided tram tours and frequently contributes articles to The Ghost Writer.

Walking on Gators


by Patrick Higgins

Anyone who sails in the skinny waters of the Ten Thousand Islands, as l regularly do on my catamaran Tropicbird, will occasionally bump the bottom. And so I suppose it’s inevitable that if you stomp around the swamp often enough, you will eventually step on an alligator. I did so for the first time a few weeks ago.

Far from scary it was quite Pythonesque (of the Monty variety). Mike Owen and I were alone deep in the Fak, about 1,000 yards west of East Main surveying some ghost orchids. It was just before the September deluge and water was scarce.

We found ourselves in a broad, shallow depression where there was still 6-8” of water and were focusing on pop-ash trunks about 6 feet above the ground. Mike was ahead as I was determined to make my own discovery, which I didn’t, of course – at least, not of a ghost.

As I put my foot down, a gator whipped around in a lightning splash and grasped onto it. Now, you have to look at this from the poor gator’s perspective. It had nowhere to go as there wasn’t water elsewhere; so it probably had elevated down as I approached, pressing itself hard against the bottom to gain a few inches of cover. It can’t be pleasant to have 240 pounds step on your back. Its reaction was purely defensive.

Luckily I was already raising my foot as its teeth fastened onto my boot, so it had a grip on the sides on my sole rather than the top of my foot where I would have felt the bite force. Also, it was only a five-footer.

So there we were; the gator’s teeth stuck momentarily in the rubber sides of my boot’s sole and me hopping backwards on one leg dragging the creature with me whilst trying to keep my balance with my stick – all the while trying to shake the darn thing off and shouting, “Mike, I got a five foot gator on my foot!” This impasse lasted only a few seconds. I think the gator was as keen to let go as I was for him to do so and maybe even had his teeth stuck.

Mike almost stepped on a cottonmouth coiled on a dry patch during the distraction but was most solicitous, insisting if there was any skin broken I go to the hospital because of the risk of infection. But the only injuries were my pride and a few small perforations in my boot sole. I did get some kudos, though, because scientist to the end, even in my excitement, I hadn’t exaggerated the gator’s length. When we approached him afterwards sure enough he was five feet, and with nowhere to hide, he rotated around to face us and scowled.

I suppose seeing the humor of the moment even as it happened comes from a long, albeit sporadic, association with reptiles. Growing up my father wouldn’t allow us to keep any pets that could harbor fleas, and so by eleven years old I had a caiman living in my bath tub and a collection of snakes and lizards.

I should mention for the benefit of those whom I lead on swamp walks, that it was entirely my own fault and that when I lead the public groups I always pre-reconnoiter the route so I can concentrate on their safety and enjoyment. In any case, our swamp walks are during the cooler months when gators are less active or inactive. As I often tell my parties: they normally avoid humans, don’t feed when the water temperature is below 70°, and like all predators are very cautious about injury so won’t tackle prey bigger than themselves. And even if you’re not six foot one like me, when you’re in a group you seem like a big organism.

I’ve never actually encountered an alligator on a public swamp walk in the water. If we see one it’s usually on the tram and by that, in case I’m alarming any potential tram tour participants, I mean on the old logging trails which in the Fakahatchee we have come to call trams, not on the tour vehicle! But just knowing they are out there, along with black bears and panthers, adds to the enjoyment of being in one of Florida’s last remaining wilderness areas.

Patrick Higgins is a National Association of Interpretation Certified Interpreter, Vice-President of the Friends of Fakahatchee and Project Manager for the development of the Boardwalk Master Interpretive Plan.

One man’s fruit; another man’s poison

by Patrick Higgins

After spending July in England I was ready for a Fakahatchee fix. So still jet-lagged I headed to the swamp, stopping first at Big Cypress Bend Boardwalk to see how our new signs were faring. Donning my Fakahatchee cap and in a matching shirt, I was an obvious target as I stepped out of my SUV and was quickly waylaid by a charming French couple and their ten year old daughter. They asked if the Indian Village was worth visiting. Hmm – a common misconception that our new entrance will address.

They had pulled over to picnic and complained they had just been on an airboat tour and not seen a single gator. They quoted their guide, “with so little water gators are hard to find.” This was August. When I left the rainy season was in full swing. What was up?

I ended up giving our French guests an extended tour, but sure enough there wasn’t any water until the gator hole, except for the small pond in the root hollow created by a toppled tree. Nevertheless they were delighted. I was able to point out a well camouflaged 6 ft female alligator with half a dozen hatchlings in the borrow ditch. The hatchlings were the smallest I’d ever seen and couldn’t have been more than a day old. After that a barred owl obligingly flew in and roosted not 10 ft from us and a six lined skink let us get close–up and personal. Their day was made. The new signs were holding up well by the way.

My next stop was to check out Six-pipe slough on Janes Scenic Drive. Instead of water gushing through the culvert, there was barely as much water as we had for our winter swamp walks. If rain didn’t come to the Fakahatchee soon, and lots of it, the season ahead looked tough. It was then that I spied the marbled-green fruit of a pond, aka custard apple.

Pond apples, (Annona glabra) with their cherry-like bark, big glossy leaves and buttressed trunks are one of my favorite trees. They bear the largest fruit of any of our natives and its light wood was used by Calusa and later Native Americans to make fishing floats. The pond apple also happens to be the larval food of the giant sphinx moth; the pollinator of the ghost orchid. Although the vast majority of our ghosts are found on pop ash trees, about 15% utilise pond apples.

Ripe pond apple

Ripe pond apple fruit has poisonous seeds, mild yellow flesh, and is an important wildlife food. Although sometimes called alligator apple, it’s more commonly consumed by turtles, birds, raccoons and squirrels.

. The creamy yellow flower of the pond apple with petals and sepals in 3s

The creamy yellow flower of the pond apple with petals and sepals in 3s.

I collected a fallen fruit and sliced a wedge out with my knife, being careful to avoid the poisonous seeds and took a bite. Not quite ripe – the flesh hadn’t yet turned yellow. Perhaps a passing vehicle had detached this one prematurely. Its taste was not unpleasant, although a bit insipid with just a hint of passion fruit. But it’s an important wildlife food, hence one of its other aliases alligator apple, although more commonly it’s consumed by turtles, birds, raccoons and squirrels.

Pond apple trees were once much more common in Florida. Patrick D. Smith, in his A Land Remembered, paints a portrait of a vast bygone pond apple forest that grew along the southern shores of Lake Okeechobee, swarming with moon vine, airplants and Carolina parakeets that has since been destroyed by drainage dikes to make way for sugarcane and other agriculture.

Like most of our tropicals, the pond apple is at the northernmost limit of its range. They naturally occur on both sides of the Atlantic aided by their buoyant fruit and range from South Florida through the West Indies, to South American and West Africa.

Due to its hardiness and tolerance of brackish conditions A. glabra has been used as a rootstock to graft some of its more desirable cousins, such as soursop (A. muricata) and sugar apple (A. squamosa). What’s one man fruit is another man’s poison. In Australia escapees from this process have become highly invasive, especially in the wet tropics of northern Queensland where ironically, or maybe in a case of poetic justice, the invasive pond apple threatens their melaleuca wetlands, as well as some native mangrove communities.

The Friends of Fakahatchee’s Captain Franklins Adams remembers a large pond apple swamp along Janes Scenic Drive in the late 1950’s and early 60’s when the Fakahatchee was still a State of Florida Wildlife Management Area run by the old Game & Freshwater Fish Commission.
Franklin says, “My family and friends would camp and sometimes hunt the area for turkeys or buck deer. Janes Scenic Drive had not been designated and the old main logging road was then referred to locally as the Copeland Grade.”

“The pond apple swamp location as I recall was near the west end of the Copeland Grade primarily on the south side of the tram. In the evening wood ducks would fly into the pond apple swamp to roost for the night. We sometimes camped in the wide spot on the south side of the grade where today there are some sour orange trees, the Fakahatchee sign and a water gauge location. On the opposite side are the old rock borrow pits.”

“1961 was a drought year and may have been the year that fire was able to enter the pond apple swamp and burn the muck down to the limestone foundation. Nothing remained of this beautiful area and subsequent wet seasons filled the limestone cavities with detritus.”

Franklin has been back a number of times to try and find the pond apple swamp’s remains but there’s no trace of it. For now we’ll have to be content with a scattering of trees along our trams and Janes Scenic Drive and the population deep in the swamp.

The Fakahatchee Wetlands

by Anthony (Tony) Marx

Photo taken by the author off Janes Scenic Drive.

Photo taken by the author off Janes Scenic Drive.

The Fakahatchee Ecosystem is unique. Although part of the United States mainland, it contains plants that exist only within its borders (or very close by); others are found in the Caribbean, Central and South America. Many elements contribute to this delicate and fragile wilderness, each dependent on the other. Its preservation has enabled us to experience what much of South Florida looked like prior to the twentieth century.

South Florida has a sub-tropical climate, but the Fakahatchee Strand Preserve State Park itself actually enjoys a tropical climate within its depths. Thus, a mild temperature exists year round, slightly warmer in winter and slightly cooler in summer, perfect for the rare ferns, bromeliads and orchids that exist year round. Some are visible from the Boardwalk and on the hiking trails, while others only reward those who venture into the interior swamps off the trail, usually by joining a ranger-led swamp walk.

Much of the Fakahatchee is natural wetland, meaning it existed  before  man  began altering its topography, but it includes uplands and aquatic systems, too. Seen from the air it presents a mosaic of contrasting colors. It includes sweeps of dun-colored upland prairie studded with contrasting green hammocks of tropical hardwood and clumps of pineland rooted on higher ground. The interior is a dark green forested swamp studded with stands of tall Royal Palms poking above the canopy. These are matched only by the occasional Bald Cypress which escaped the loggers attention sixty to a hundred years ago.

The ground slopes gently south, 2” to 4” per mile, quickly becoming wetter, with a central linear strand slough (wide, straight, shallow moving river) fed from two directions. Water enters the park from the north and flows south to disperse in the marshes south of US-41, and finally into the coastal mangroves. The depth ranges up to 6’ in summer, leaving a series of ponds that remain during the dry winter months. Theses provide the humidity needed for vegetation and a water source for the park’s wildlife. South of US-41, the wetlands consist of mostly open, saw grass prairie, with patches of marsh and swamp and shallow water courses navigable by kayak. Finally, mangroves herald the transition from brackish to saline, signaling proximity to the Gulf and home to the endangered American crocodile.

Although the Fakahatchee recovered from its period of logging from 1913 and reaching maximum output in the 1940s and 1950s, it is also partly an ‘Altered Ecosystem’. It is somewhat impacted by run-off from agricultural and ranchland to the north, its crucial water supply sources being the Okaloacoochee State Forest near Immokalee and the Caloosahatchee basin to the north-west. In both cases, before reaching the Park, the water flow competes with the needs of agricultural businesses and now the expanding development of Ave Maria and the  huge planned city of Big Cypress stretching east from North Naples to Immokalee. Thankfully, during its progress through the Park, these pollutants are captured and absorbed by wetland plants, helping protect the crucially important spawning areas without which commercial and recreational fishing cannot survive.

The hiking trails and road access are all located in the northern half, starting at the Copeland ranger station, using the beds that were formerly logging rail tracks known as ‘trams’. The interior of the park is bisected by the dirt-surfaced Janes Scenic Drive, with hiking trails leading off it, elevated on what were originally the beds of trams hauling lumber out of the interior. These are the West and East Main, Mud Tram, and Uplands Trails. For those preferring a less strenuous introduction to the Park, the Boardwalk on US-41, located 7 miles west of the Everglades City Junction, offers enchanting views of the tropical forest and its wildlife, accompanied by newly-designed interpretive signs along its length.

The never-ending battle of conservationists versus developers will continue. The good news is that nearly 70% of Collier County is preserved under the jurisdiction of local, state, federal, and private management. More is being added on a regular basis, either by county and state government acquisition or private bequest. This is how the Fakahatchee State Park has expanded since 1974, when only a third of its present size at the outset.

At 85,000 acres it is the largest of Florida’s State Parks and is surrounded by protected and preserved land managed by other authorities. It is bounded on the north by the Florida Panther Preserve, and the Picayune State Forest adjoins its western side. The vast Big Cypress National Preserve is on its eastern side across State Road 29, and the Everglades National Park Ten Thousand Islands section is on its south-eastern corner.

Tony Marx is a Florida Master Naturalist and FOF Board Member. He is also a volunteer interpreter for the Fakahatchee guided tram tours and frequently contributes articles to The Ghost Writer.

Fire, a Natural Part of our Ecosystem

By Patrick Higgins

I just happened to be leading a combined tram tour and swamp walk on the 29th of January when the Park’s Burn Specialist, Steve Houseknecht, and his team were setting Lee-Cypress Prairie ablaze. It was of course a prescribed burn, in this case of some 400 acres from the road to the margins of the swamp beyond.

Trundling down Janes Scenic Drive on the Ghost-rider, our passengers had a front row view of the burn crew, decked out in their helmets and yellow Nomex jackets, igniting the dry grasses and shrubs with their drip-torches. We traversed a smouldering landscape with flames lapping at hammocks in the distance. Hawks moved from perch to perch just ahead of the fire head watching for fleeing prey or perhaps some fresh barbeque. Later, wading in Six Pipe Slough we had the novel experience of snow in the Fakahatchee, as white ash rained down upon us.

South Florida is the lightning capital of the USA with an average of 25 lightning strikes per square mile and more thunderstorm days than anywhere else in the country. This, coupled with seasonal drying, makes wildfire a natural component of our environment. As a consequence most of our ecosystems have evolved to be fire dependent.

The majority of lightning strikes are between June and September, coinciding with the peak of our wet season, so the resulting fires tend to be lighter in touch and more localized. However wildfires from thunderstorms in late spring, when there’s lots of accumulated dry fuel about, tend to be wider sweeping, more severe, and can even alter the soil structure. But with the creation of roads and  canals that act as firebreaks and fragmentation of the habitat, this cycle cannot take its natural course. So we have prescribed burns that attempt to mimic this otherwise natural phenomenon. The Fakahatchee has the largest prescribed burn program in Florida’s State Park system.

Fire maintains the habitat by preventing succession. Without fire, shrubs and trees would invade our marshes and wet prairies, eventually drying them out. Fire releases and recycles nutrients locked up in plant tissue, keeps non-fire adapted invasive plants in check, and alters the landscape spatially, creating clearings and opportunity for burnt areas to experience increases in native wildflowers, birds and other wildlife. In the case of prescribed burns, they also protect Park neighbors and facilities by reducing potential fuel for wildfires.

New growth abounds n Lee Cypress Prairie just two weeks after a prescribed burn. Photo by Patrick Higgins.

New growth abounds in Lee Cypress Prairie just two weeks after a prescribed burn. Photo by Patrick Higgins.

I tramped across the charred landscape 2 weeks later and was greeted by fresh sweet green shoots of grass already 6 inches high being grazed upon by white-tailed deer. More remarkable were the thistles in flower everywhere, poised to create seeds to colonize new terrain. The burn also revealed some of the prairie’s normally hidden structure like the recumbent trunks of saw palmettos, cap rock, or circles of cypress knees around old logged stumps, as well as a littering of white shells from the previous seasons’ apple snails.

Of particular interest to me was how the prairie hammocks had faired. Many of the smaller islands of cabbage palm and saw palmetto appeared incinerated, although I knew within a few weeks the palmetto’s blackened trunks would be sprouting new fronds. The hardwood hammocks however were largely untouched. Some are protected by shallow perimeter moats, but it’s the deep shade of their interiors that create microclimates with higher humidity that seems to keep them safe. In most cases it was just the volatile wax myrtle around their margins that had burned.

There’s no water in most of the borrow ditch paralleling lower Janes Scenic Drive right now, so the burnt prairie is easy to access. Try investigating it on foot before the grasses gets too high again and compare it with unburnt Copeland Prairie to the east. Personally I’m waiting for autumn when the muhly grass ought to be spectacular. It flowers best after a good burn.

Restoring the Giant Air Plant

by Mike Owen and Karen Relish

The Friends of Fakahatchee are an important part of a team to rescue bromeliads, especially the Tillandsia utriculata or Giant Air Plants, seemingly a favorite of the non-native Metamasius callizona or Mexican Bromeliad Weevil. Typically, after about 10 to 15 years of growth, the Giant Air Plant sends up a seed stalk or spike up to 6 feet long, produces flowers in June, then produces thousands of seeds during spring, and then dies unlike many of the other Florida bromeliads which can also reproduce vegetatively by pupping.

Chad Washurn of Naples Botanical Garden, Fakahatchee biologist Mike Owen, and Bruce Holst of Selby Botanical Garden with the Giant Air Plants.

Chad Washurn of Naples Botanical Garden, Fakahatchee biologist Mike Owen, and Bruce Holst of Selby Botanical Garden with the Giant Air Plants.

The Friends of Fakahatchee contributions will assist other team members at Naples Botanical Gardens, Selby Botanical Gardens and possible affiliates to educate, quarantine/monitor, then regularly treat with an insecticide the recovered plants as well as provide materials to re-attach to hosts, and logistical support for the Giant Air Plants from Fakahatchee Strand Preserve State Park and from its headwaters Okaloacoochee Slough State Wildlife Management Area and other Florida Natural Areas.

Work on the Giant Air Plant and other bromeliads at Fakahatchee and other parks around the state was initiated at University of Florida by Teresa Cooper for her graduate work. She is currently working for Indian River Research and Education  Center in Fort Pierce with Ron Cave. From December 2008 through December 2013, Mike Owen and primarily two Fakahatchee volunteers continued and expanded the monitoring within the center of the Fakahatchee Strand along 7 miles of Janes Scenic Drive. With the dedicated efforts of the two volunteers, including one who entered the data and created the graphs, the monitoring efforts produced an annual snapshot of the Mexican bromeliad weevil invasion that reached the sampling area in 2010. The December 2013 data revealed an over-80% decline of the Giant Air Plants, especially  north  to  south  along  Janes  Scenic  Drive.  Upon seeing this in graph form, Mike Owen obtained the necessary permission and permits to collect some of the known remaining surveyed  plants, approximately 160 of them, to place under the conservation efforts of the Gardens’ staff and volunteers to enable a healthy seed stalk and seed production.

On November 13, 2014, 16 Giant Air Plants were ready to be returned to the Fakahatchee. Using the data gathered, they were returned to as close to the same tree, height, and distance from Janes Scenic Drive that they originated. Team members from both Gardens, including interns from Belize, and Fakahatchee staff and volunteers assisted in this process. By the time these seeds mature into plants, we are hoping with the tireless team efforts that we will see them produce healthy seed stalks and successfully release thousands of seeds back to the Fakahatchee Strand. Each year in November the plants, safely protected from the ravages of the weevil larvae at the two  Botanical  Gardens,  that  produced  a  spike  during  the previous June will be returned to the Fakahatchee Strand to continue the release of seeds into the swamp.

Flying Rodents They’re Not

by Patrick Higgins

It was dark. Glen Stacell and I were rolling slowly down Janes Scenic Drive with lights dimmed in his pick-up truck. There was just the soft crunch of tires on gravel. The silhouettes of cabbage palms and cypress contrasted against the evening sky.  Each of us had an arm out a side window holding a small black device aloft listening for clicks.  We were reconnoitering our upcoming new moonlit tram tours and searching for some of Fakahatchee’s bats.

Eastern pipistrelle, Fakahatchee's smallest bat. Photo by Dr. J. Scott Altenbach

Eastern pipistrelle, Fakahatchee’s smallest bat. Photo by Dr. J. Scott Altenbach

Eight of Florida’s 13 species of bat frequent the Fakahatchee; the Seminole bat (Lasiurus seminolus), Big brown bat  (Eptesicus fuscus), Brazilian free-tailed bat (Tadarida brasiliensis), Evening bat (Nycticeius humeralis), Eastern pipistrelle or Tricolored bat (Pipistrellus subflavus), Northern yellow bat (Lasiurus intermedius), Rafinesque’s big-eared bat (Corynorhinus rafinesquii)  and the endangered Florida bonneted bat (Eumops floridanus).

The Seminole bat, Northern yellow and pipistrelle are solitary roosters utilizing clumps of Spanish moss, dried palm fronds and old tree cavities.  The others are colonial roosters. The Brazilian free-tail and Big-eared have now adapted to man-made structures.  The Brazilian likes bridges and picnic shelters, and is particularly partial to the crevices under barrel tile roofs, a penchant shared with bonneted bats. The Big-eared strays less far from its preferred forest habitat and is more likely to use old cabins and sheds. The evening bat is less picky and sometimes found in the folds of patio umbrellas.  All are slow reproducers with typically a single pup born each spring.

Like all bats they are the subjects of many misconceptions, even being referred to as flying rodents. Bats are in fact in an order all of their own, Chiroptera, from the Greek aptly meaning hand-wing, and may be closer related to primates than rodents.

They are a diverse group accounting for almost 20% of all known mammal species and can be divided into two suborders; the megabats or flying foxes of the old-world tropics, sometimes referred to as fruit bats, and the ubiquitous microbats which include all of Florida’s species.

Our bats are small; ranging from our smallest, the Eastern pipistrelle with a 9” wingspan but weighing in at a mere ¼ oz, to our largest, the Florida bonneted bat with a 20” wingspan but, still only about 1 ¼ oz weight. Despite their diminutive body mass bats are extraordinarily long-lived. Some bats weighing less than an ounce have lifespans of 30 years.

Flying foxes in particular put paid to the myth ‘as blind as a bat’. They have excellent binocular 3D color vision.  But even the smaller eyes of our microbats have highly refractive lens and are densely packed with rods. They have good night vision, but nobody goes around saying, “as sharp as a bat’s eyes at night.”  Microbat eyesight is however made largely redundant by their ability to echolocate: to use reflected sound waves to map their environment in the same manner as dolphins.  This remarkable sixth sense allows them to determine distance, size, shape, texture, speed and direction.

Not only are bats not the harbingers of evil portrayed in horror films, they are highly beneficial, providing many important ecosystem services. Not least of these in Florida is that our species are all insectivorous typically consuming their own body weight in insects every night.  Depending on the size of the bat and size of the insect this can total several thousand ‘bugs’, many of which may be agricultural pests.  In other parts of the world they provide pollination services as well.

As Glen and I proceeded, our scanners periodically rippled to life, with the distinctive slower pulses of bats in the search mode, followed by increasingly frantic chirps as they closed on their targets, culminating in a feeding buzz which ends abruptly when the insect is scooped by wing or tail membrane into its mouth.  Occasionally we also picked up insect noise when it intruded into the bats’ frequency range, but this was a like a low muffled roar and easily distinguishable.

We think of nocturnal predators as being quiet, but bats are noisy, broadcasting at 110-120 decibels, which is the same level as standing next to a jackhammer. So it’s a good thing that most of their calls are ultrasonic and well above 20 kHz, the upper limit of human hearing.  It makes perfect sense being so loud if you’re trying to resolve a moving object as small as a mosquito.

Our Swiss bat detectors are only the size of cigarette packs but quite sophisticated, as well as quite expensive, although I won’t say quite how much in case my wife reads this.  They automatically scan the full chiropteran echolocation frequency range, which varies by species. They then transform the chirp into our audible range, modulate its volume, and display its frequency. This provides a clue to identification, but only a clue as the call ranges of many bats overlap.  However, armed with this and the knowledge of what bats are likely to be found in any given area, one can make a pretty good guess.  Even more sophisticated bat scanners can record wave patterns that can be downloaded onto a computer for analysis and positive identification.

But this aerial combat is not all one sided.  Many insects can detect the bats signals and take evasive actions or apply countermeasures.  Some moths will fold their wings and suddenly drop to the ground. Tiger moths take a different tack. Their larvae feed on toxic plants that make them taste nasty so they emit a series of clicks to warn off an approaching bat.

Earlier in the day Glen had a sugared a few trees along our route with a homemade concoction of rum, molasses and brown sugar.  I would rather have drunk it, but he painted it on several trunks in the hope of attracting moths. The idea was to see what the bats might be feeding on.  It worked well up north, but we didn’t have any luck with it that night, so will revert to the time-honored tradition of a white sheet and backlight for our tours. We had better success with the fireflies and were able to attract a few towards us using a keychain LED flashlight, but you have to get the flash pattern just right for the particular species.  We look forward to sharing our new skills with our moonlight tram riders and boardwalk-after-dark strollers.

Night Ramblings

Night Ramblings
by Patrick Higgins

 View of South Oxfordshire from atop the Chilterns at Watlington Hill. Photo by Patrick Higgins

View of South Oxfordshire from atop the Chilterns at Watlington Hill. Photo by Patrick Higgins

Late July found me stumbling down a sunken way with Martha in the pitch dark of a moonless night. Our rough path was hemmed in by ancient yew and beech trees. We were in the Chiltern Hills of South Oxfordshire – an area designated as being of Outstanding Natural Beauty, a Site of Special Scientific Interest and a Special Area of Conservation about 15 minutes from our son’s house in Watlington where we were staying.  The broad bottomed ditch we were negotiating dated back to Saxon times.  In the darkness with the clinking of key chains and water bottles one could almost hear “the tramp of Saxon foemen, Saxon spearmen, Saxon bowmen” although more commonly this path would have been trampled by generations of Saxon farmers taking their animals to market; merchants with their wares travelling between settlements and woodsmen hauling timber and charcoal.

Further down, the sunken way was bisected by an old Roman road, now resurfaced and travelled by cars. For some unknown reason the Roman routes are always straighter than most of our modern English highways. Behind me, back up the hill, our ditch led to the Ridgeway, Britain’s oldest byway dating back over 5,000 years, which stretched from the Norfolk coast to that of Dorset, linking up Neolithic sites like Stonehenge and Avebury.  It’s hard to escape history in England, but we were in search of the glow worm (Lampyris noctiluca), cousins to Fakahatchee’s fireflies in Aston Rowant National Nature Reserve.  However, in the dark my mind kept wandering to the Fakahatchee because I had to give a talk locally on the Everglades Ecosystem and was also planning some new night-time interpretive programs for the upcoming season back in Florida.

The Reserve is a mosaic of chalk grassland, beech woodland and Juniper scrub sitting atop 300 feet of chalk, formed 350 million years ago from the compressed calcite shells of microscopic Foraminifera that lived in the warm, shallow seas that once covered southern Britain.  Chalk grassland is a unique and fragile habitat, important for both its beauty and wildlife value. It is the product of centuries of grazing by animals on nutrient poor chalk soils and is characterized by a short turf rich in herbs, flowers, butterflies and grasses, and like the Fakahatchee also in orchids, although here they are all terrestrial.

Comparisons between the ecosystems continued to flood my thoughts as we bumped along. In one we employ prescribed burns to maintain the habitat. Here, it’s the grazing of a large flock of speckle-faced sheep and a few Dartmoor ponies that controls the spread of young scrub and keeps chalk grassland healthy.

Aston Rowant, at only some the 500 acres, is a classic example of the threat to biodiversity through islandization and habitat fragmentation. Especially as even this small, precious parcel is sliced into two by a massive cut for the six lane M40 motorway from London to Oxford which paralleled our route just over the rise. It was further affirmation why the Fakahatchee is important; not just because of its unique plant communities, but also as Florida’s largest State Park because of its scale. When it comes to maintaining biodiversity, size does matter!

Back in Florida swallow-tailed kites would just be beginning to assemble for their annual 4,500 mile return migration to South America. Here there were Red kites (Milvus milvus).  They had been reduced to just a handful of pairs in Wales through past persecution. It was mistakenly believed that they were a threat to gamebirds and livestock, but recently they have made a remarkable comeback. Through a reintroduction program using chicks taken from northern Spain there are now some 250 breeding pairs in the Chilterns.   With a 5 ½ foot wingspan Red kites are a much larger bird than our swallow-tail, weighing 2 – 3 pounds versus 10–20 ounces and their ecological role is different too. Rather than being canopy feeders they are primarily carrion feeders, filling the role of vultures, although they will take small mammals too if caught in the open. The locals who once persecuted them now throw the bones from their Sunday joints out on to the lawn to watch them swoop in, a practice sadly that does not encourage the kites’ dispersal into new territory.

Field of yellow meadow ant mounds. Photo by Phil Champion

Field of yellow meadow ant mounds. Photo by Phil Champion

In Florida the instant we step off the road we are on the alert for fire ant nests.  Here there is an unseen benevolent ant, the Yellow meadow ant (Lasius flavus). The chalk grassland and other undisturbed ancient pasture areas are dotted with myriads of small grassy domes that look almost like neatly planted helmets. These are actually ant-hills, some over a hundred years old. Inside of each is a colony of up to 5,000 meadow ants that feed the by farming the sap sucking aphids that live on the roots of the surrounding forbs and grasses.  The ants milk the greenfly for honeydew which they carry back to their colony and in the winter will eat the aphids themselves. Their subterranean activities control damaging insects, open up the soil keeping it porous and their droppings fertilize the grasses’ roots. They also have a curious relationship with the Chalkhill blue butterfly (Polyommatus coridon). Attracted by secretions they will bury the pupa, unintentionally protecting it from predators.

Wingless female glow worm (Lampyris noctiluca). Photo by Barry Crowley

Wingless female glow worm (Lampyris noctiluca). Photo by Barry Crowley

After about 45 minutes bumbling about we finally detected the steady green glow of our target, a glow worm.  It was about a foot off the track, naturally in completely the wrong spot deep in the woodland.  Glow worms of course are not a worms at all but a bioluminescent beetle just like our related firefly.  In their larval stage they are predatory and hunt snails, which why calciferous habitats that favour snails like chalk grasslands are preferred. As adults they rarely feed.
In the glow worm’s case it is only the inch long wingless female that glows significantly.  She had climbed up a dried grass stem about 12 inches above the ground then curled her abdomen slightly upward to display the last few segments of her abdomen where her glowing organs are located in hope of attracting a passing male.  Unlike American fireflies she can’t readily turn her glow on and off – it’s rather like a very slow starting fluorescent tube, which takes about 20 minutes to cycle so they don’t flash.  Misplaced deep in the woods she would be very lucky to have any success.  As well as attracting a mate, the glowing abdomen is a warning to predators to stay away – bioluminescent chemicals taste bad.

Nevertheless, hers is a very efficient light source. Unlike incandescent light bulbs that only, transform about 3% of the energy used into light, bioluminescence is generally 90 to 98% efficient.  The light is produced by a reaction between calcium, luciferin and ATP in the presence of the catalyst luciferase and oxygen, using nitric oxide as a chemical on/off oxygen valve. It is the switching on and off of the oxygen flow which allows American fireflies to flash.  Specific flash patterns are used to identify other members of their species, as well as members of the opposite sex and even. In the case of some Photuris fireflies, it is to mimic the light signals of other firefly species to lure, kill, and eat them.  Studies of America’s most common Photinus species show that females are more attracted to males that flash longer and faster. A flash can bring either sex or death!  We shall be trying a bit of mimicry ourselves on our moonlight tram rides down Jane’s Scenic Drive this season to see if we can attract any eager males.  It’s just a case of getting the response timing right.

Anyways, that solitary glow worm by the trail was the only one we saw that night.  We scoured the open grassland to no avail.  I guess we missed the peak by about a week, but even then observers were only seeing a dozen specimens a night on this site. Light pollution as well as habitat loss is taking a toll on these interesting insects.  We’re pretty lucky in the Fakahatchee.