This week for Flora and Fauna Friday, we have a tropical butterfly with a transparent caterpillar, the Brazilian Skipper (Calpodes ethlius).
The Brazilian Skipper is large for a skipper, at about an inch-and-a-half in length with an elongated forewing. The underside of their wings is a golden-brown with four white cells, the technical term for spots, in a diagonal line towards the outer edge of their hindwing. From above, their wings are a dark brown towards the center with a half-dozen or so large, blocky white cells. Their eye is surrounded with a prominent white eye-ring. Overall a drab butterfly that’s a bit overgrown and with some anatomical quirks. Being a large skipper, Brazilian Skippers are strong and fast fliers, zipping around between flowers and perches. Their large size and an extra-long proboscis allows this butterfly to easily sip nectar from larger flowers, those usually reserved for acrobatic hummingbirds and spelunking bumblebees. Brazilian Skippers are mainly crepuscular, flying at dawn and dusk, and so are scarcely seen during the day. They’re most easily found in close proximity to their host plants or as caterpillars.
Brazilian Skipper caterpillars host on two genera of plants, Canna and Thalia. Here in the Lowcountry, we have two native host plants for the Brazilian Skipper, Golden Canna (Canna flaccida) and Powdery Alligator-Flag (Thalia dealbata). Both are rare with few natural populations in South Carolina. However, they are also both popular and hardy aquatic plants commonly sold by plant nurseries, alongside the even more popular and widespread Canna Lily (Canna indica) from South America. All three species are natural host plants for the Brazilian Skipper, which is adept at eating them! The Brazilian Skipper actually goes by another name in the nursery trade. Its infamous alter ego is the “Larger Canna Leafroller” and they can do some damage, albeit superficial damage, to their ornamental host plants, which has evoked the ire of horticulturalists. Brazilian Skipper caterpillars feed using the leaf-rolling technique. Young caterpillars will cut two slits in the edge of a leaf, then fold it over on top of themselves self like a little caterpillar taco, attaching the folded leaf in place with silk. There the caterpillar is safe from the elements and will poke its head out to chew on the edge of its roof. When it eats itself out of house and home, it will move to a new spot on the leaf to tuck itself into a bigger bed and breakfast. These caterpillars are also very unique in appearance. They have a khaki colored head, transparent skin, and green innards spider-webbed with white tracheal tubes, this insect equivalent of lungs being visible through their see-through skin. Eventually this caterpillar will grow to a chunky three inches in length. At that point, it will move to a new leaf and fold it in half. In this final cozy abode it will pupate into a powdery, pale green chrysalis and eventually emerge a fully formed butterfly.
This year for Pollinator Week (6/17 – 6/23) we’re doing a 7-part series about native pollinators on Edisto Island!
Today let’s dive into one special group of pollinators, the Butterflies. Butterflies are a subset of the moths, the superfamily Papilionoidea. Butterflies all share 2 common features: they fly during the day and have “clubbed” antennae. In the Lowcountry, we have about 130 species of butterfly, which come in a wide array of sizes, colors, shapes, behaviors, and life histories.
Butterflies, to be frank, are mediocre pollinators. They have a long, prehensile proboscis to sip nectar out of flowers at a distance. This means they don’t walk around on flowers much and don’t pick up a lot of pollen. Some plants are specialized for butterfly pollination but, generally, butterflies aren’t moving all that much pollen around. Yet, butterflies have 3 special characteristics that make them valuable to pollinator habitat conservation.
First, butterfly caterpillars feed on plant leaves. This makes butterflies a plant “pest” in some ways but, in reality, they and moths serve as a natural check-and-balance for native plants. If one plant has a banner year, moth and butterfly populations spike, eating more of that plant and keeping it in check, so it doesn’t dominate a habitat. In turn, wasps eat these caterpillars so they themselves don’t get out of hand.
Second, butterflies are a great indicator species for the health of a pollinator habitat or ecosystem. Butterflies are also easy to spot and identify, which is important for indicator species. Butterflies respond quickly to environmental changes, weather, and climatic trends. So, their populations follow conditions that ecologists want to keep track of. Being plant eaters, they are also sensitive to insecticide and herbicide use, declining faster than other species and indicating a problem sooner.
Third, butterflies are the quintessential pollinator ambassador for folks. They’re big, they’re pretty, they’re easy to watch, they’re harmless, and can be raised from egg to adult in a classroom terrarium. Their herbivorous caterpillars demonstrate the inextricable link between insects and plants and their adults like the same big pretty flowers we humans love to plant. They’re the poster children of pollinator conservation.
This year for Pollinator Week (6/17 – 6/23) we’re doing a 7-part series about native pollinators on Edisto Island!
The Hutchinson House is an iconic local landmark and touchstone for interpreting African-American history on Edisto Island from the Emancipation through Reconstruction and onward. EIOLT has worked the last 8 years to restore the house and interpret its history.
Just as the House is significant to interpreting our history, the land it sits on is a stellar example for interpreting sea island Pollinator Habitat. EIOLT purchased the adjacent 9-acre lot in 2019 and have diligently maintained its existing wildflower meadows. These fields burst to life in fall with a profusion of native wildflowers that are inundated in a billowing haze of pollinators! We’ve even built a pollinator garden on site to better showcase the beauty of these meadows.
These wildflower meadows are what are commonly referred to as an “Oldfield” habitat. As the name implies, oldfields are agricultural fields left to go fallow. Often, they’re burned or mowed sporadically to control woody plants but otherwise are left to their own devices. An oldfield’s beauty is in its simplicity and purity. A field gone fallow allows for the local “seed bank”, the native plant seeds persisting in the top soil, to be exercised and showcased. Over time, new plant species will germinate from the bank and duke it out in the oldfield free-for-all until an equilibrium is reached. Throughout that process, plant structures, micro-habitats, complex ecological interactions, and diversity will build, creating stellar pollinator habitat.
“Pollinators” are not a monolithic group, it’s a loose collection of animals that spread pollen. Some need pollen, others nectar, some leaves, others leaf litter, hollow stems, bare soil, wet mud, or dead trees; every species has its own unique list of living conditions. Pollinators are a diverse group and, consequently, a diversity of habitat is needed to support them all. Diverse site conditions breed a diverse assemblage of plants, which in turn create a diversity of habitat, a sprawling miniature metropolis of stems and leaves, to support a diversity of pollinators.
Check out this video about the wildflower meadows at the Hutchinson House:
This year for Pollinator Week (6/17 – 6/23) we’re doing a 7-part series about native pollinators on Edisto Island!
Many of our flowering plants rely on pollinators to spread their pollen far and wide. But why do plants need pollinators? Insect pollination encourages cross-pollination between two unrelated plants, increasing a population’s genetic diversity and resiliency to climatic shifts, disease outbreaks, and environmental changes. It also allows a plant avoid producing the massive amounts of pollen needed for wind pollination, making the process more efficient for the plant. This frees up resources the plant can allocate towards growth, or producing nectar.
Nectar is the currency that plants use to pay pollinators for their hard work. It’s a deep-rooted mutualistic relationship. Native plants rely on insects to keep their populations healthy and insects rely on the plants for food. In the end, both groups are better off. This makes pollinators a lynchpin in the long-term health of our native ecosystems, and many plants need cross-pollination to set seed at all. Pollinators are thus extremely important to human agriculture. Many fruit trees and vegetables need insect pollination to produce viable fruit. If insect populations drop, agricultural yields can plummet even though all other site conditions are ideal. This is why recent trends of insect and pollinator declines are disturbing and worrying to ecologists. European Honeybees have been declining due to a myriad of pressures, such as increased misuse of insecticides in residential settings, foreign diseases and parasites becoming more established, and new invasive species, like the bee-eating Yellow-legged and Japanese “Murder” Hornets. These rising threats are highly damaging for beekeepers and agriculture. In parallel, our native pollinators aren’t able to pick up the slack due to similar pressures, such as systemic misuse of insecticides in residential areas, over-reliance on insecticides in agricultural settings, invasive plants, and habitat loss. The Monarch Butterfly and both the Southern Plains and American Bumble Bees are even candidates for listing as endangered species. However, we can mitigate these losses locally if we all help provide our pollinators with pollinator habitat.
This year for Pollinator Week (6/17 – 6/23) we’re doing a 7-part series about native pollinators on Edisto Island!
First things first, what’s a pollinator? It’s simply an animal that moves pollen from one flowering plant to another. Most often this is a flying insect but birds, bats, and ants will also pollinate. We have 5 main groups of insects that serve as pollinators: Bees, Wasps, Flies, Beetles, and Butterflies.
Bees are the powerhouses of the pollinator world. They do the lion’s share of pollination. Adults eat mainly nectar and feed their larvae pollen and nectar. Our native bees, especially Bumble Bees, do the bulk of the pollination in natural areas and small gardens. Honeybees, an exotic domesticated species, pollinate agricultural fields and orchards.
Wasps are anti-heroes among pollinators. Adult wasps eat nectar and do a lot of pollination in the process. They also hunt caterpillars, spiders, and other insects to feed their young. This helps control insect populations and stabilizes an ecosystem.
Flies are the unsung heroes of the pollinators. They do a ton of pollination on smaller flowers that are not often visited by other pollinators. There are also many plants with extremely specialized pollination tailored to just one species of fly. Another group, the Flower Flies, have carnivorous larvae that feed on pests that plague pollinator plants.
Beetles are our pollinator old guard. The original pioneers now stuck in their ways. Beetles are sedentary and uncoordinated, making them inefficient pollinators. However, some plants take advantage of these bumbling beetles to douse them with pollen and to make unwitting pollinators. Butterflies are the celebrities of our pollinators. They’re good looking and they soak up a lot of energy, resources, and attention, but don’t do all that much.
Butterflies are very well adapted to drink nectar and not get pollen on them. Yet, certain plants make use of butterflies as preferred pollinators. Further, butterfly larvae feed on plants, this helps control plant populations and keeps any one plant species from dominating an ecosystem.
This week for Flora and Fauna Friday we’re on the lookout for a rare, coastal plain endemic, backwater wildflower, Powdery Alligator-Flag (Thalia dealbata).
Powdery Alligator-Flag is one of just two species in its genus found in the United States. That genus, Thalia, is our only representative for the Arrowroot family, Marantaceae. Powdery Alligator Flag is a bona fide rare plant here in South Carolina, with only a smattering of population sites in our coastal counties. Edisto Island is notable in being a population stronghold for this rare plant.
Powdery Alligator-Flag can be found in practically all of our natural freshwater backwater wetlands around Edisto Island. It will most readily inhabit shady marshes and shallow swamps around the Island. It is even mildly salt tolerant, and can handle a touch of saltwater intrusion. Powdery Alligator-Flag is an emergent aquatic plant, growing in mucky soil in a foot or so of water along the water’s edge. It spreads laterally through rhizomes into large clumps, or along an entire shoreline in good conditions. Its foliage can reach three to five feet in height with large elliptical leaves a foot long and half as wide. It’s a perennial plant and can even be evergreen through a mild winter. All and all, it looks a lot like a taller, bulkier Canna Lily. However, the most recognizable feature of this plant is not its prominent foliage but its handsome flowers. In about June, Powdery Alligator-Flag gets into full bloom sending up thin flower stalks five to eight feet high. These are capped with a cluster of powdery platinum-white flower buds that eventually bear delicate deep-violet petals. The plant will continue to bloom until fall and the flowers will mature into a spherical nut-like fruit. These nuts are mostly hollow and float, allowing the singular seed within to journey across the water. Despite its rarity and specialized life history, Powdery Alligator-Flag is actually a very hardy plant and a perfect native addition to any wetland garden, pond edge, or detention basin. Powdery Alligator-Flag tolerates full sun, partial shade, mucky soils, fluctuating water levels, freezing, and even a dash of salt. In return it provides towering foliage, beautiful flowers, and wildlife habitat. Thanks to these traits, it’s grown and sold widely in aquatic plant nurseries. Powdery Alligator-Flag is also a host plant for the Brazilian Skipper butterfly (Calpodes ethlius), a large golden-brown skipper common in subtropical regions where Canna and Thalia plants are abundant. These butterflies are scarce in South Carolina but locally abundant where Powdery Alligator-Flag is established.
This week for Flora and Fauna Friday it’s a long-necked, fowl-flavored, slow-moving slough citizen of the Southeast, the Chicken Turtle (Deirochelys reticularia).
The Chicken Turtle is found throughout the coastal plain of South Carolina. It is scarcely seen in many locales but is particularly common here on Edisto Island. Chicken Turtles inhabit freshwater marshes, bottomland forests, backwaters, and other shallow, vegetated freshwater wetlands. Chicken Turtles share many physical characteristics with other turtle species in the family Emydidae, but have a few standout features of their own. In general appearance, their shell is a bit taller and smoother than other pond turtles. Their carapace has a faint yellow, net-like pattern across its top and their plastron is a solid golden-yellow below. A Chicken Turtle’s front legs have a thick yellow stripe running from toes to shoulder and the side of its head has thin, parallel yellow lines. However, the most standout feature of the Chicken Turtle is its head and neck. The head of a Chicken Turtle is noticeably longer than other pond turtles and its neck is proportionately almost twice as long as its cousins! Chicken Turtles use their long neck to hunt crayfish, small fish, insects, and amphibians. It allows them to reach out and suck up or snap down on prey at a distance in the shallow waters they inhabit, where moving quickly isn’t an option.
Chicken Turtles have some other interesting quirks as well. Unlike most turtles, they nest in fall and winter, rather than spring. Their eggs in tandem have a prolonged incubation time in response to colder temperatures, preventing hatching until spring. Further, rather than moving to a new home when their shallow wetlands dry out in summer, they instead head to the uplands to aestivate underground until the wetland floods again. Aestivation is similar to hibernation but is done in summer, usually by reptiles or amphibians and when the weather is too hot or too dry. Chicken Turtles also grow rather fast for a turtle but have a surprisingly short lifespan of only about 20 years.
Lastly, the name “Chicken Turtle” is a reference to the historical account that these turtles taste like chicken! It also is a fitting description of this turtle’s long chicken-like neck. Chicken Turtles were once a mainstay in the southern delicacy of turtle soup, as they apparently taste much better than our other turtles. Nowadays, turtle soup is no longer on the menu in Charleston. But it’s still a delicacy on the other side of the Earth. Until recently, there were practically no limitations on the collection of wild turtles in South Carolina. This resulted in South Carolina becoming a hotbed for poaching and the black market sale of our native turtles overseas to Asian meat markets. Our turtle populations crashed as a consequence and new laws were passed in 2020 to staunch the decline and crack down on poaching.
This week for Flora and Fauna Friday it’s a tough, lush, turf-grass that’s a possibly native to the Sea Islands, St. Augustine Grass (Stenotaphrum secundatum).
St. Augustine Grass, also called Charleston Grass, is a perennial, occasionally even evergreen, turf-grass. It is tolerant of heavy shade, wet soils, poor soil fertility, drought, and even saltwater intrusion, but does not tolerate full sun nor frost well. It grows as a groundcover with heavy stoloniferous stems that run along the surface of the soil, dropping roots as they go. Its leaves are a lush, deep verdant green, are soft and drooping, and can exceed a foot in length in ideal conditions, if left untouched. Its flowers are a flattened, thickened spike that rises straight up above the ground. It will bloom throughout summer. St. Augustine Grass is a host plant for many of our native butterflies’ grass-eating caterpillars, such as the Carolina Satyr, Southern Skipperling, Whirlabout, and Clouded Skipper.
St. Augustine Grass is found widely throughout the Sea Islands of South Carolina and Georgia and is planted extensively for lawns throughout the Lowcountry of South Carolina, as well as Florida, the Gulf Coast, and other subtropical climates worldwide. The natural range of St. Augustine Grass is something botanists are still debating and contesting. Many sources claim it is native to the coastline of the Southeast, others the Gulf Coast, and others say it is native to South Africa. A clear answer isn’t yet known. What I can tell you for sure is that the first place it was described by science was in 1788 by the botanist Thomas Walter from Charleston, South Carolina. More modern research appears to indicate that this grass is an extensive species-complex spanning from Charleston through the Gulf Coast and Caribbean down to South America and across the Atlantic Ocean to West and South Africa, with various lineages that have spread both naturally and by humans, including into the Pacific. All other species of the same genus, Stenotaphrum, are found in the Pacific Ocean. As it stands, the origin point of St. Augustine Grass as a species is still unknown. In my personal opinion, it likely originated in Africa and was spread to North America either naturally by ocean currents thousands of years ago or by Europeans during colonization sometime during the last five centuries.
Let’s finally address the elephant in the room. (Hello there Mr. Elephant!) Today I’ve spotlighted THE turf-grass of the Sea Islands, Charleston Grass itself. Turf-grass lawns and monocultural turf-grass lawn management have been catastrophic for native plant and insect biodiversity across the entire United States since the 1940s. A traditionally managed turf-grass monoculture contains no native plants and can sustain next to no native insects, let alone wildlife. I do not, and will never, advocate for creating nor maintaining a turf-grass monoculture around your home, business, et cetera. But if I can’t convince you not keep a turf-grass lawn, then at least pick the lesser of the evils. In my opinion, the old wild-type variety of St. Augustine Grass is the closest thing to a native turf-grass we have in the Lowcountry. I’ve inherited some amount of St. Augustine Grass in every lawn or park I’ve ever managed and I can tell you from firsthand experience that, when managed tactfully, it will support some native wildlife and won’t exclude all other native plants. It is by no means a team player and will crowd out many smaller plant species. Yet if left shaggy, and the “weeds” left alone, St. Augustine Grass can provide wildlife value and management utility in our coastal landscape, without exacerbating the harm already done, and can be readily converted to a more natural botanical community later on. However, a native grassland or meadow will always be the best replacement for any lawn.
This week for Flora and Fauna Friday it’s our darling bird on Deveaux Bank, the Whimbrel (Numenius phaeopus).
Whimbrels are a cosmopolitan species, meaning they can be found all across the globe. Yet, they have four subspecies, three that breed in Europe and Russia and then our Hudsonian Whimbrel (N. phaeopus hudsonicus) who breeds in North America. Within the Hudsonian Whimbrel, there are two disjunct populations, one on the west coast of the Pacific Ocean and one on the east coast of the Atlantic Ocean. Here on Edisto Island, we see the Atlantic population of the Hudsonian Whimbrel.
The Whimbrel is a large shorebird, at about a foot high on stout black legs. Their plumage is a camouflaged pattern of mocha-brown and bone-white, each color breaking up the other in dots and dashes into a seamless cryptic checkerboard across their whole body. Their most standout feature is their long black bill that curves down towards the tip and, at the opposite end, blends back onto the head into a set of dark racing-stripes across their dome and a heavy line through their eye. Apart from their larger and scarcer cousin the Long-billed Curlew (N. americanus), there’s nothing else in South Carolina like a Whimbrel! Whimbrels spend their days in our saltmarshes and tidal creeks resting and foraging. Their diet consists largely of fiddler crabs, which they snatch from the surface of the marsh or pluck from deep within their intertidal burrows. Apart from fiddlers, they also eat a good deal of other crustaceans as well as some small mollusks and fish when available. When tides are high, Whimbrels retreat to oyster banks, hammock islands, and sometimes even docks, to rest and digest until the tide ebbs. Whimbrels use their time here on Edisto Island to put on the pounds they need to fly up to the Arctic Circle to nest in the Canadian tundra. Some Whimbrels overwinter here in the marshes of the Edisto Rivers and the ACE Basin. Some younger birds may even spend their first summer on the South Carolina coast, forgoing migration. However, the prime time to find a Whimbrel on Edisto Island is during their spring migration.
Edisto Island is of the utmost importance to the survival of the Atlantic Hudsonian Whimbrel population. During spring migration, nearly fifty-percent of our total Atlantic population will simultaneously use Deveaux Bank as an overnight roost, flying in by the thousands as the sun sets. Deveaux is an undeveloped sand bank at the mouth of the North Edisto River, in between Seabrook and Edisto Islands, which is owned and managed by SCDNR. In 2019 the importance of Deveaux Bank was made known globally to ornithologists and shorebird conservationists through research by SCNDR biologists. From the research, scientists had learned where the Whimbrels were roosting, at an astonishingly high concentration, but not where they were all dispersing to forage during the day. In 2024, new research to answer those questions is ongoing and its preliminary results have revealed the importance of Edisto Island and the ACE Basin to the survival of the Atlantic population of the Hudsonian Whimbrel. Our migrating Whimbrels all roost on Deveaux at night but, in the day, they disperse across the tidal marshes of Edisto Island, Toogoodoo Creek, Bohicket Creek, St. Helena Sound, the Kiawah River, and even all the way over to Beaufort to feed. They are dependent on the entirety of the tidal ACE Basin and its surrounding sea islands’ marshes to survive, with Edisto Island housing the closest all-you-can-eat fiddler crab buffet to Deveaux Bank. Whimbrels use their time here on Edisto Island to put on the pounds they need to fly up to the Canadian tundra in the Arctic Circle to nest.
Without SCDNR’s management of bird sanctuaries like Deveaux Bank and the prior decades’ worth of tireless land protection work by the Edisto Island Open Land Trust and our peers in the ACE Basin Task Force, we could have already lost the Whimbrel on the East Coast by this point. Whimbrels are in steep decline and Deveaux Bank and the ACE Basin represent what may become their last stronghold on the East Coast. With each passing year, South Carolina’s preeminence, cooperation, and forward thinking actions in the arena of landscape-scale conservation are being realized, recognized, and solidified as the standard by which all other regions of the country must compare, the ACE Basin being a crown jewel of those efforts. EIOLT is a proud member of this cooperative conservation community and thanks you, dear reader, for your support that makes it possible for EIOLT to continue our efforts to protect land containing critical habitat for imperiled coastal species, like the Whimbrel, who depend on Edisto Island to survive.
This week for Flora and Fauna Friday, it’s a departure from the norm to talk more generally about an ecological concept, and to highlight some foreign flora and fauna. Today you’re getting a crash course on the major Invasive Species of the South Carolina Lowcountry.
I’ve been writing this series for nearly seven years now and, if you’re a loyal reader, you may have noticed that I tend to look at practically all aspects of our Lowcountry ecosystems with an air of positivity and reverence, bordering occasionally on unfeigned evangelism. I tend to take the side of the scorned and maligned members of our natural world. The vipers, sandburs, spiders, coyotes, thistles, and even the rats; I’ve praised them all and preached of their importance.
Today’s subject is different. There are a select few species that have wrought my utter contempt. Beings so wretched and vile they deserve no safe harbor in this landscape. Invaders from exotic lands who undermine the foundation, tarnish the beauty, and corrupt the sanctity of this Sea Island we’ve toiled so hard to conserve. I’m speaking of invasive species, both plant and animal. Insidious and existential threats to the ecological integrity of Edisto Island and the whole of the Lowcountry.
First, let’s define what an invasive species is. An invasive species is an introduced exotic organism that has a measurable, harmful, damaging impact on native species and, by extension, the natural ecosystem which it invades. To expound upon this we have to also detail what an invasive species is not. Firstly, a native species cannot be invasive within its natural range. This generally extends to “Range Changers” which are native species that expand their range into a new area due to favorable changes in the landscape, for example Coyotes and Cattle Egrets. An “exotic” species is simply an organism native to someplace else, which now exists in a place where it never naturally occurred. Further, not all exotic species are harmful or damaging. An exotic species that establishes in a new area but doesn’t cause any meaningful harm is referred to as a “naturalized” species. So it’s only when things end up where they’re not supposed to be AND when everything else starts to go wrong as a consequence that an “invasive species” manifests.
But, before we continue, it’s important to note that an invasive species is not invasive in its own native range. It has a home where it belongs and where it plays an important role in its natural ecosystem. There, they also predators and pests that keep them in check and competing species to level the playing field. It’s only when they’re introduced as an exotic in a foreign land that they become freed from these natural biological controls and can usher in an ecological plague.
Out of all the invasive species that occur in the South Carolina Lowcountry, of which there are well over a hundred, there are three plants and two animals that come to my mind as the worst of the worst. These five have precipitated unfathomable ecological destruction and economic burdens throughout the Southeast: Chinese Privet (Ligustrum sinense), Feral Hogs (Sus scrofa), Chinese Tallow Tree (Triadica sebifera), the Red Imported Fire Ant (Solenopsis invicta), and Common Reed (Phragmites australis).
Chinese Privet (Ligustrum sinense) is the poster child for invasive plants, a wanted poster that is. Chinese Privet was introduced to the United States in the mid-1800s. It has opposite, evergreen leaves and showy clusters of white, spring-blooming, fragrant flowers. As such, it was planted widely as an ornamental shrub. However, following the Civil War, many agricultural fields were laid fallow and Chinese Privet began leaching out into the Southern landscape. Its dark blue-purple drupes in summer are attractive to birds, who gorge themselves before flying off, spreading the seeds as they go. Chinese Privet can grow on a wide array of soils, tolerates full sun and partial-shade, spreads clonally, and is evergreen with a dense canopy. These characteristics create the crux of what makes it so terrible. Once established on a field row or roadside, it begins a generational march into the forest understory, creating an impenetrable privet thicket that slowly snuffs out all plant life below it. When a tree falls and light hits the forest floor, it creates a pocket of prime songbird habitat, which Privet then exploits. The birds unknowingly hop-scotch the Privet into these clearings, allowing it to advance its front with ease. Soon the Privet saturates the forest floor and withers away the surrounding biodiversity. Privet is an over-bearing threat in the upstate of South Carolina. Here on Edisto Island, we have a fair bit of privet but, thankfully, it is mainly kept in check by our native Sea Island flora. Our native trees and shrubs often grow fast enough and thick enough to freeze Privet in its tracks before it can spread. Yet, it often still secures a foothold in fallow fields and around human developments. A quick tangent, many of our invasive plants here in South Carolina originate from China or Japan. This is not a coincidence. Certain regions of Japan and especially coastal China have a very similar climate and soils to the Southeast. So, when brought here, their plants grow equally as well, but without the other species that naturally control them.
Feral Hogs (Sus scrofa) are a special kind of blight. They look like a typical pig, albeit more athletic and hairier, because that’s all they are. Feral Hogs are descendants of domesticated pigs, gone feral. Their ancestors escaped from captivity centuries ago and returned to life in the forest. Just the wrong forests on the wrong side of the ocean. Although they’re fully feral, they’ve retained all those traits that make pigs a versatile and adaptable livestock. Feral Hogs can reproduce at an astonishing rate, with sows able to breed at less than a year old and capable of raising 15 or more piglets a year. Under ideal conditions, a Feral Hog population can more than quadruple in a year. Hogs are unbelievably intelligent, being smarter than most dog breeds, and they learn how to evade people, defeat barriers, and avoid traps rapidly. They’re also big, tough, and fast. Weighing over 100 pounds, not much can threaten a full grown sow. Full grown, a boar can exceed 200 pounds and wields a face full of pointed tusks. Hogs, especially boars, can be aggressive and a deadly threat to people and pets. A Hog’s nose is incredibly sensitive to both smell and touch, letting it find food buried underground. Yet it is also strong enough to function like a plow and is capable of upturning the most hard-packed soils and digging under fences. Hogs will eat anything and everything, and I mean that. They are true omnivores and will eat plants, tubers, seeds, nuts, insects, reptiles, fresh carrion, bird and sea turtle eggs, and any mammal or bird they can catch. All these factors combine to make Feral Hogs, by no exaggeration, an existential threat to the conservation of many rare and endangered species in the South. Feral Hogs can single-handedly decimate native plant and wildlife population, and may even extirpate them from the landscape. They destroy farmer’s crops at every chance they get and pollute waterways by upturning, wallowing, and defecating in creeks and wetlands. Their constant digging and eating of native plants plows and primes the soil for invasive plant species to set seed and take root, further destroying an ecosystem. Wherever they go, Feral Hogs wreak havoc and bring destruction. The only silver lining to this blight is that they are at least made of bacon! There are ostensibly no harvest limits or hunting restrictions on Feral Hogs in South Carolina. This is to encourage continuous and relentless population control. However, a sickening trend has developed nationwide, some people have deliberately spread Feral Hogs to new counties and states in order to create sport hunting opportunities. This is a highly illegal and a morally bankrupt practice, but still it continues to spread Feral Hogs within the United States. We are extraordinarily blessed on Edisto Island to not have any established populations of Feral Hogs. However, Hogs do occasionally swim across the South Edisto River. Thankfully, so far, they have been kept off our Island by our responsible local landowners.
Chinese Tallow Tree (Triadica sebifera), or perhaps more widely known as Popcorn Tree, is in my opinion the most destructive invasive plant established on Edisto Island. It has alternate, diamond-shaped leaves, white seedy fruits, and a pale-gray lightly flakey bark. Chinese Tallow was first introduced to the United States in the late 1700s for soap making but later became a popular ornamental tree due to its colorful fall foliage and large white seeds. It is well adapted to growing in coastal wetlands and tolerates shade, full sun, well drained soils, saturated soils, and even occasional saltwater flooding. Once established, Chinese Tallow grows unimpeded, as its foliage is toxic to herbivores. It grows quickly into a small tree and can begin to produce seeds when it is only a few years old. Its seeds are coated in a thick wax, which gives them their characteristic white color and the “popcorn” common name. This wax is an attractive food to many birds, including bluebirds, woodpeckers, and cardinals. They swallow the seeds whole, digest the wax, and pass the seed some time later somewhere else. This disperses Chinese Tallow seeds far and wide. At the same time, seeds that aren’t eaten fall to the ground in winter. Our Lowcountry wetlands are often flooded in winter and these seeds float, allowing them to disperse by wind and floodwater to distant shores. Some seeds inevitably germinate below the parent tree as well. These two dispersal mechanisms result in Chinese Tallow taking root in every inaccessible corner of an intact wetland in as little as five years. That’s when the real problems start. Chinese Tallow is an ecosystem engineer, one that engineers the subversion and destruction of healthy wetland ecosystems. Once establishes in a wetland, its seeds can lay dormant in the soil. All it takes is one disturbance event, like a flood, a drought, a fire, or salt intrusion, to activate these seeds like sleeper agents, which quickly grow into full blown trees. Each one of these trees acts like a water pump that sucks water from the wetland soils and evaporates it into the atmosphere. This upsets the balance of the wetland, which allows for more Chinese Tallow seeds to germinate. This creates a positive feedback loop where Chinese Tallow starves the native wetland plants for water and then takes their place the following year. This eventually creates a nearly pure stand of nothing but Chinese Tallow, which then wrests control over the wetland’s hydrology. Eventually, if the soil dries out enough, upland plants may try to intrude. The upland plants shade out the tallow and the Tallow stops pumping water, which causes the wetland to flood, which kills the intruding upland plants, which allows the Tallow to repopulate. It is truly a diabolical strategy, a vicious cycle by design.
Red Imported Fire Ants (Solenopsis invicta) are small ants with a dark-red head and thorax and a darker-red or black abdomen. They build large, porous mounds with a sponge-like appearance and no central entrance. Fire Ants are likely the single most destructive invasive animal to southeastern wildlife biodiversity, even more so than Feral Hogs. The difference between these two invasive animals is that Hog damage is often isolated and is impossible for any land manager to miss. Fire Ant damage is omnipresent and insidiously hidden. Red Imported Fire Ants were unintentionally introduced into the United States in about 1920. These ants have then spread like a fire across the United States since and can be found in every corner of South Carolina. The full extent of the ecological damage that has been caused by Fire Ants is almost impossible to quantify or gauge. Fire Ants eat practically any animal they can reach and they can live in practically all habitats from fields to savannas, from forests to beaches, from parking lots to even rice field marshes. Over the last century they have systematically invaded every corner of South Carolina and secretly waged an unyielding war of attrition on all fronts against our native wildlife. They’ve imperiled turtles, butterflies, quail, salamanders, bumblebees, snakes, bats, and even our native ants, nothing is safe from the onslaught of Fire Ants. What makes Fire Ants so particularly destructive is multi-fold. To start out with, unlike all our native ant species, they’re violently aggressive, attacking anything they encounter whether it be a threat, potential food, or a human foot just minding its own business. Our native wildlife have no adaptations to deal with these unprovoked swarm attacks. But fleeing does little good as Fire Ants are everywhere. Fire Ants have spread so far and wide because they’re adaptable, but also because of their teamwork. Normally, ant colonies fight with other neighboring ant colonies, even within their own species, over resources and territory. However, Red Imported Fire Ants colonized the United States through just a few isolated introductions. This has resulted in all the Fire Ants being one giant extended family, meaning they see each other not as enemies but as allies. The consequence is that all the Red Imported Fire Ants in the United States operate as one gargantuan, unstoppable supercolony which persists at unnaturally high colony densities and, like an out of control fire, slowly and surely consumes everything it envelopes. This unceasing horde of ants has decimated the populations of many ground nesting birds, turtles, endemic amphibians, pollinators, and native insects. Much of this destruction occurred rapidly and out of sight, before ecologists even knew it had begun. When wildlife populations plummet, it has ripple effects throughout an ecosystem. If there is a population decline in pollinators, herbivores, and/or seed dispersers, their decline can cause native plants to either suffer or grow out of control, creating a positive feedback loop known as a trophic cascade. These ecoregion-wide ecosystem changes caused by Red Imported Fire Ants have been ongoing for over a century now in some places, their scale and severity are so acute yet diffuse as to be nigh incalculable by ecologists.
The truly insidious thing with these five invasive species is that there is currently nothing that we can do to thoroughly control them. They are all still ever spreading on the American landscape. All have been running rampant, mostly unchecked, for nearly a century or more but some have only truly unleashed havoc in the last 50 years. Once any one of them becomes truly entrenched, they’re practically impossible to stamp out. The only solutions to controlling them so far require expensive, continuous, active management just to keep their populations under control. If these efforts cease, the destruction would be unfathomable. This makes the idealistic concept of preserving ecosystems in their natural state (E.G. taking a hands off approach and letting nature take its course) now untenable in the Southeast. Right now, the damage done by the hands of man can only be staunched with the deliberate and desperate actions of those same hands. Taking a hands off approach with our natural landscapes today is tantamount to throwing what’s left over to the Hogs.
That’s also just the big 5. There are over a hundred more invasive species in South Carolina and more keep appearing with each passing year. Some have even made their debut in the State in our own backyard, for example the Asian Long-horned Beetle (Anoplophora glabripennis) outbreak in Hollywood, SC and the Cuban Bulrush (Oxycaryum cubense) invasion in Green Pond, SC.
However, all hope is not lost! The more people who recognize and rectify these existential environmental threats, the sooner we can snuff them out. Biologists are feverishly working on developing biological controls to wrangle these five pests into submission and one day these efforts will come to fruition. In the meantime, ecologists and land managers toil day in and day out to expunge invasive species from our natural landscapes. You too can play a vital role, especially when it comes to controlling invasive plants. Take a gander around your garden, your yard, your driveway, or your property. You might be surprised to find where invasive plants have already taken root. If they have, cut them down and dig them up. Then keep an eye out for when, not if, they return. If you don’t have land yourself, considering volunteer with SCDNR, USDA, EIOLT, or other local nonprofits on invasive species work days. On the other side of the coin, when you’re perusing plants at your favorite big box store or nursery, double check that that shrub you’re eyeing isn’t a Trojan horse. If we all do our part, if we plant native plants and root out invasive species, we can conserve and improve what we’ve still got left of the Lowcountry’s natural history.
