This week for Flora and Fauna Friday we have the wick of the savanna, the tinder of the timberlands, the powder keg of the pineywoods, Threeawn (Aristida spp.), aka Wiregrass.
Here in South Carolina we have a little over a dozen species of Threeawn. In the Lowcountry, that number dips to about seven decently common species. Four of the dozen species I want to highlight: Southeastern Slimspike Threeawn (Aristida longespica), Arrowfeather Threeawn (Aristida purpurascens), Southern Wiregrass (Aristida beyrichiana), and Carolina Wiregrass (Aristida stricta).
Southeastern Slimspike Threeawn is the most common species of Threeawn you’ll find on Edisto Island. It’s an annual species that grows most often in sunny sand barrens and other dry clearings. It has a compact and skinny growth form, sparse flower stalks that reach upright to about knee height, relatively small seeds, and narrow leaf blades that curl when they dry. Arrowfeather Threeawn is the most widespread species statewide but not as abundant on the Sea Islands. It grows on deep sands and dry ridges in pineywoods, barrens, and savannas. It’s a perennial bunch grass with an upright form, dense flower stalks reaching up to about waste height, fairly large seeds, a burgundy-purple wash to its upper foliage, and blade-like leaves that curl as they dry. Southern Wiregrass and Carolina Wiregrass are a package deal. The two species were recently split and look quite similar. Carolina Wiregrass is found in the northern Sandhills of South Carolina down our eastern border to and through the coastal plain of North Carolina, but not in the Lowcountry. Southern Wiregrass, however, is found throughout the southern point of South Carolina, from the Francis Marion National Forest to Aiken and down through the savannas to the Savannah River. The two Wiregrasses reside in frequently burned Longleaf Pine savannas and grow on deep sands. They’re a perennial bunch grass that spreads clonally, grows as a dome of thin wiry leaves, and bears narrow but dense flower spikes which may reach up to hip height.
Threeawns are remarkable both physiologically and ecologically for their seeds and foliage. The seeds of Threeawns have three conspicuous awns. That’s where they get the common name. Awns are a long pointed projection of the leaf-like bracts that surround a grass’s flowers and often sheath the seeds. (Recall a head of wheat or barley. Those pointy bits are the awns.) The three awns of Threeawns are notable for twisting around each other, like a basket in a wrought fence, before then bending at a right angle. It’s a shape that’s hard to describe. Imagine an umbrella without the fabric and only three arms, but with a spiral twist in the middle. This twisted tripod of a seed has some innovative properties that enhance its chances of finding a good home. Firstly, that umbrella like shape helps the seed catch the wind and float further than it would just falling straight down. Although, they’re too heavy to float indefinitely. Second, the awns catch on the fur of passing mammals or pants legs of hikers, letting the seeds hitchhike to a new home. Saving the best for last, the awns are a compliant machine that operates as a drill fueled by humidity. These three awns are grown with an asymmetrical composition; one side of each wiry awn is denser than the other. When these awns dry, their difference in internal density causes one side to shrink more than the other, twisting and bending the base of the awns like a clock spring. When rain or heavy dew wets the seed, the awns absorb the water and stretch back out into their original straight shape. As sun dries the seeds, they twist back up. This acts on the same principal as an analog hygrometer, used to measure humidity. You can even grab a seed off a plant on a dry day, breathe heavily onto it, and watch the thing spin in your hand! This hydrated helical spin has an important function, drilling the seed into the soil. When the seed falls to the ground, the heavier seed side lands pointed down. If it’s lucky, it will land on bare soil, but it might be blocked by debris or duff. That’s when the drilling begins. Even in the driest of climes at the driest of times in the Lowcountry, our air is still sopping wet with water. That water condenses and drenches the ground as dew every night. Then, the scorching suns evaporates it all back into the air. This process repeats every day, spinning and shifting our little Threeawn seed. When the awns straighten, their tips anchor into the substrate as they twirl and push the seed forward, deeper towards the soil. When they dry and curl back up, the awns smoothly slide against the litter like a free spinning one-way ratchet, preserving the progress of the seed’s downward spiral. This cycle repeats daily, until the seed strikes pay dirt and sets roots in the sandy soil below. It’s a truly amazing adaptation!
Yet, spinning seeds ain’t the only trick this grass has hidden up its leaves. The foliage of Threeawns is built to burn. When old leaves dry, they do so thoroughly and then twist like a corkscrew together into a ball of tinder. This effect is most evident in the annual Slimspike Threeawn. However, both the Wiregrasses take this strategy to the extreme. Wiregrass is an ecosystem engineer. It combines its flammable foliage with its dome-like shape, its deep and expansive root system, and clonal nature to dominate the understory of the Southern Pine savanna. Hand in hand with Longleaf Pine it turns the forest floor of the pine savanna into a web of fuses, linking the ring of pitch plastered pine needles around each Longleaf Pine into a continuous carpet of fuel. The foliage of Southern Wiregrass in particular is so flammable, it will purportedly still burn in wet conditions. Through this smoldering smothering of the understory, Wiregrass fans the flames of renewal brought by natural and controlled fire. When Wiregrass’s prescription for fire is met, it is astounding how stable an ecosystem Longleaf Pine and Wiregrass have forged, its beauty jaw-dropping and biodiversity awe-inspiring. I’ve even read research suggesting the mycorrhizal fungi living in the sands of these fire-ravaged lands have a third hand in the conspiracy for conflagration, supporting the growth of the pyrophytic plants, promoting the flammability of their duff, and suppressing fire-phobic plants and fungi. The interwoven complexity of the southern pine savanna is an intoxicating realm to ecologists, extending above the pine boughs and below the tortoise burrows with a breadth wider than the Wiregrass roots that tie it all together.
If you’d like to get a gander up close at the glory of our southern pine savannas, SCDNR’s brand new Coosawhatchie Heritage Preserve in Yemassee, SC is a prime site to see a proper Wiregrass savanna. Or if you ever find yourself upstate cruising down HWY-1 through McBee, SC, Carolina Sandhills NWR is unforgettable detour!
This week for Flora and Fauna Friday we have a cryptic mammal with some crazy physiology, the Southern Short-tailed Shrew (Blarina carolinensis).
The Southern Short-tailed Shrew is native to the Southeast and found throughout the Atlantic Coastal Plain from Virginia to Texas as well as up the lower Mississippi River Valley into Kentucky. Shrews are an odd family of creatures belonging to the mammal order Eulipotyphla, the true insectivores. This order also contains moles and hedgehogs. Shrews share several traits with moles, notably a dense coat of soft fur, a soft pointed snout, and tiny poorly formed eyes that render them practically blind. Shrews, at a glance, look a lot like a mouse or vole, being about the same size and shape. But even a cursory up close examination reveals just how different they are.
Here in the Lowcountry of South Carolina, we have three species of shrew: the Southeastern Shrew (Sorex longirostris), North American Least Shrew (Cryptotis parvus), and the Southern Short-tailed Shrew (Blarina carolinensis). The Southeastern Shrew is about two-inches long with a tail half that length and ruddy brown fur. The North American Least Shrew is a little over two-inches long with a tail a third of that and gray-brown coat. (Meaning the Southeastern Shrew is actually smaller.) The Southern Short-tailed Shrew is by far the most common shrew you’ll find on the Sea Islands and throughout the Lowcountry. It averages three-inches in body length with a tail somewhere between a quarter to third of that length and with fur a dark-gray often peppered with silver. In the upstate and mountains can also be found the Northern Short-tailed Shrew (Blarina brevicauda), which is very similar overall to its Southern sibling but about an inch longer and double their weight. The Northern Short-tailed Shrew is the largest Shrew in the United States.
Shrews, for the most part, lead a predominantly fossorial lifestyle, rooting around in leaf litter or digging tunnels underground that protect them from predators, keep out the elements, and facilitate hunting. A Shrew’s wedge-shaped face, dense fur, and strong legs enable its subterranean homebuilding. This makes Shrews quite cryptic critters. They are rare to encounter in the wild by chance. Unlike moles, they don’t leave obvious tunnels and molehills on the soil’s surface to track them. So most often people find them deceased lying atop the ground somewhere or by chance unearth them while gardening.
Southern Short-tailed Shrews inhabit a variety of habitats from forests to fields to floodplains but seem to most prefer habitats underlain by productive, moist soils which support relatively healthy and diverse plant communities. That’s not because they eat those plants though. It’s because they hunt the herbivores and detritivores that subsist on those plants. Shrews are ravenous predators with an insatiable appetite. They have an absurd metabolic rate, meaning they need to eat year-round, day in and day out, both day and night and throughout the dead of winter just to stay alive. Their heart rate clocks in around 900 beats-per-minute, about 75% that of a hummingbird and over ten times that of a human! To sustain this hyper fast metabolism they hunt nonstop and subsist on a diet of earthworms, slugs, snails, insect larvae, arthropods, and fungi, alongside just about any other small animal they can sink their teeth into. That’s possible because Short-tailed Shrews are venomous. You read that right. This mammal packs a neurotoxic venomous bite that’s strong enough to paralyze mice and other small vertebrates. A Shrew’s venom is secreted into its saliva. So it has to chew that venom into its prey, rather than inject it like a viper or spider would. This venom isn’t fatal to humans but is reportedly quite painful. The Northern Short-tailed Shrew, with its larger body, is the most accomplished small game hunter among all the North American Shrews. Yet, you can still add small reptiles, mammals, and amphibians to our smaller Southern Short-tailed Shrew’s menu. As a defense mechanism against its own predators, the Southern Short-tailed Shrew has musk glands, which it uses to exude a nauseating stench to ruin the appetite of would-be Shrew eaters. Often times the Shrew doesn’t sense the threat until it’s already mortally wounded, which is likely why we find dead, uneaten Shrews lying about the place. Although it doesn’t help that particular now deceased shrew, it might keep that particular Bobcat or Gray Fox from bothering other Shrews going forward.
Now, the astute among you may be wondering how a stinky nearly blind furball, the size of your thumb, with the heartrate of a hummingbird, venomous or not, can even find enough food to survive. Thank you for that perfect segue my dear hypothetical reader, now I can talk to you about the senses of the Short-tailed Shrew. Our shrew has a fantastic sense of smell, allowing them to sniff out food both underground and on the forest floor by the trace scents animals leave behind. They also have a well-developed tactile sense, allowing them to feel vibrations underground to further hone in on prey. Their sense of hearing is similarly well developed. Oh, and they can echolocate. Yeah, you read that one right too. This venomous, bloodthirsty mammal can echolocate. Their acute hearing affords them the capability to utter clicking noises, which bounce off the surrounding landscape like radar, and permit Shrews to perceive nearby objects by listening for the echoes. Their echolocation ability isn’t nearly as well defined as a bat’s, but it certainly gives the Southern Short-tailed Shrew another tool in the toolbox. Shrews need all the help they can get after all. They’re burning the candle at both ends and it’s a shrew eat mouse world out there.
This week for Flora and Fauna Friday we have the pine of the high hills, Shortleaf Pine (Pinus echinata).
Shortleaf Pine is found throughout the Southeast, including all of South Carolina. In the Lowcountry, it’s most often found on hilltops, old dune ridges, and sandhills where it grows on well-drained and often droughty soils. It’s more common inland than it is on the Sea Islands, but still appears reliably on our highest sand ridges on Edisto. You’re as likely to find Shortleaf Pine mixed in with hardwoods as you are with other pines and rarely is it ever a dominate species this close to the coast. However, further up the state, it can often be the predominant pine on certain types of sites. Shortleaf Pine is a fire adapted species and often found growing amidst Longleaf Pine Savannas and along Oak-Hickory ridges. It is not as fire dependent as some other pines but does benefit greatly from fire on the landscape.
Shortleaf Pine is one of the easier pines to identify here on the Sea Islands. It has a character clearly distinct from all our other pines. It’s small for a pine, rarely exceeding one-hundred feet in height or two feet in diameter. Overall it has a thin trunk, straight shape, densely compact crown, and few trailing branches. Upon closer examination, it has key features that help identify it. Its pine cones are small and compact, on average the smallest of all our pines, and often persist upon the branches for several years. Its needles are short and straight, rarely longer than finger length, and generally grown in fascicles of three. The fascicle, the sheathed bundle containing individual needles, is an important feature to examine when identifying pines, especially in the Upstate between young stems of our other short needled pine species. But here in the Lowcountry, we have just one other short needled pine, the Spruce Pine (P. glabra). However, it’s easy to discern from the Shortleaf Pine, with Spruce Pine having twisted needles in fascicles of two most often. (Additionally, Spruce pine grows in floodplains and has uniquely smooth twigs and silvery bark.) Further, Shortleaf Pine has distinct bark from our other pines. Overall, its bark appears smoother with larger, flatter plates compared to Longleaf (P. palustris), Slash (P. elliottii), or Loblolly Pines (P. taeda). But, when you look up close, it reveals the trademark signature of the species, resin pockets. The bark of Shortleaf Pine is peppered internally with resin pockets, which weep resin when the bark exfoliates and leave behind birdshot-sized dimples across the surface of the bark. This is a unique trait of Shortleaf Pine and makes it an easy pine to identify when mature.
Shortleaf Pine is a boon for biodiversity and for bird watchers in the winter months. In my experience, I’ve found it to be particularly attractive to songbirds for a pine. Shortleaf Pine’s dense crown of needles and prolific little cones produce a bounty of seeds and attract insects seeking shelter. These in turn make it a favorite year-round hunting ground for Nuthatches, Chickadees, Titmice, Goldfinches, and Pine Warblers. This effect is further enhanced by its resilience to growing alongside hardwoods in mixed forests.
This week for Flora and Fauna Friday we’re glancing up at our ever present warbler of the evergreens, the Pine Warbler (Setophaga pinus).
From year to year and season to season no other warbler is so consistent a sight and sound as the Pine Warbler. Throughout the Deep South and in every corner of South Carolina pines abound. And in them, Pine Warblers are found. Large for a warbler, male Pine Warblers glow with lemon-yellow from beak to breast, fading to straw-yellow in winter and grading to a dingy shade towards the tail. Females shroud themselves in that same dingy straw yellow year-round. Dull steel-blue wings bear two strong wing-bars of white. A light eyebrow, dark eye-stripe, broken eye-ring, and dull, darkened cheek faintly mark their faces. The song of the Pine Warbler is simple, one to two-dozen sharp and upward notes trilled in quick succession. Yet, subtly inconsistent in its pitch and varied in rate from bird to bird. This inconsistency helps separate their song from the similar sounding Worm-eating Warbler (Helmitheros vermivorum) and Chipping Sparrow (Spizella passerina). The Pine Warbler’s call is a single “chet” note, harsh in tone with a sucking ring and the faint bass of a bigger warbler.
Just as its namesake pines remain a static and verdant fixture of our landscape, the Pine Warbler’s place in the Palmetto State is equally constant. Yet, their behavior and diet fluctuates with the seasons. In winter, they forage the treetops both above and beyond the savannas, feasting on any arthropods they can find alongside the pine seeds they pluck and the occasional fruit. In spring, they descend readily from the pines to scavenge fields and fencerows for waking insects and to collect pine straw, incessantly singing all the while. In summer, they continue their singing as they raise their young within the pineywoods, who’ll soon leave the nest to curiously and clumsily explore the wide world of pines. In fall, they fall silent as they fatten up for winter, using their mouths to eat rather than to sing for once. Despite this seasonal cycle, throughout the year Pine Warblers are always here, shifting about the pines, as surely as shadow hang beneath their needles.
This week for Flora and Fauna Friday we have a festive forest fern, Christmas Fern (Polystichum acrostichoides).
Christmas Fern is a species of evergreen fern found across the eastern United States and practically all of South Carolina. Its deep, jade-green fronds are divided once, giving the frond a feather-like appearance. The pinnae that make up the frond are glossy, lightly toothed, have a characteristic lobe at the base that points back to the ground, and sparse, orange hairs along the stem. The spore-bearing sori on the underside of the frond present predominantly as two parallel lines of cinnamon spots. The fronds of Christmas Fern are roughly forearm length, emerging at an angle from the ground and held low like a shallow basin shin-high above the ground. Christmas Fern is perennial and will spread slowly through its roots underground, most often forming loose clusters of clumps. Christmas Fern gets it holiday name from its evergreen foliage, which stays green throughout winter. This makes it a favorite addition to festive wreaths and arrangements over the holiday season.
Christmas Fern is a denizen of deciduous forests, damp soils, and deep shade. I most often find it around South Carolina growing in creek valleys, above stream banks, on north-facing slopes, along hillside seeps, between the buttresses of oaks, and just uphill of wetlands. Here around the Sea Islands, I mostly see it in the ecotone, the transitional band of land between ecosystem types, where mixed-hardwood upland forests grade downhill into swampy bottoms, especially when downhill faces to the north. That north facing slope is important. Here in the temperate zone of the northern hemisphere, the sun is always in the southern half of the sky. Meaning slopes that face south get more sun, and slopes that face north get less. The soils of those north facing slopes thus stay in shade for much of the year and dry out less. Perfect conditions for our shade tolerant, moisture loving Christmas Fern. This effect is far stronger in the Upstate. Yet here in the Lowcountry, where elevation is measured in inches, it can still have a significant impact within a forest. Christmas Fern is a species that doesn’t tolerate disturbance well. It prefers established, mature, deciduous forests. For me, as an ecologist, that makes it a useful indicator species for intact forest ecosystems. Where I find Christmas Fern in the Lowcountry, I know I’m in a healthy forest, a place worth protecting, and to be on the lookout for rarer plants and animals.
This week for Flora and Fauna Friday we’re looking and listening for a pair of wonderfully weird water birds, our Loons (Gavia spp.).
Here on the Sea Islands, two species of Loons frequent our tidal waters, the Red-throated Loon (Gavia stellata) and the Common Loon (Gavia immer). Both species breed in the arctic, with the Common Loon also breeding across Canada and Alaska. They return to South Carolina each year to ride out the winter. Both of our Loons have a fairly duck-like silhouette but with a body sitting lower in the water, a long neck, round head, and a sharp and dagger-shaped bill. Loons prefer deep, open waters and aren’t afraid of swift currents or choppy seas. Loons need deep water because they hunt by diving, sinking beneath the waves to dart like a torpedo after fish, shrimp, and other sea life, or frogs and crawfish in freshwater lakes. They also need wide open water so they can take flight. Loons are built for swimming and consequently have legs pushed so far back on their body that, practically speaking, they can’t walk on land anymore. They pretty much have to slide and flop around like a seal. (This is why you rarely see them on land.) It also means taking flight is a struggle, as they have to take a running start, like a Cormorant or Anhinga would, but with less range of motion at their disposal. So they need a longer runway than most water birds to get airborne.
Red-throated Loons are often scarce in the Lowcountry. They prefer to whittle their winters away in the choppy, windswept waters of our beaches. They’re most often spotted along river inlets, beaches, or just offshore, bobbing on and diving under the surf in search of their next meal. They have a slender build and are about three-quarters the size of the Common Loon. Their bill is shorter, thinner, and sharper than their common cousin. This narrow bill and svelte physique give them a more streamlined appearance overall. Their winter plumage is a neutral-gray across the back speckled with white, like stars in the night. This gray extends up the nape of the neck, over the top of the head, and to end at the bill. Their throat and sides of their neck are pure snow-white, their bill a silver-gray, and eyes ruby-red. Here in South Carolina, Red-throated Loons rarely display their breeding plumage, which colors their bill black, head phosphate-gray, and their lower throat a rust-red. They also rarely ever vocalize outside of their breeding grounds in the Arctic Circle.
Common Loons are by far the more common of our two Loons. They’re also the most generalist in their habitat usage. Common Loons are abundant in lakes, inlets, sounds, tidal rivers, and major tidal creeks, particularly those close to the ocean and near confluences. They are heavy-bodied with a robust bill. Their winter plumage is quite drab, a dark-gray back running up the back of the neck to the bill, contrasted by a white throat and cheeks and with the only flash of color being their red eyes. On occasion, we’re lucky enough on Edisto to see one fully in its breeding plumage before it departs in spring. Their drab winter garb is replaced by a hood of iridescent black-green, a collar of white bars, and a black-green back studded thoroughly in small squares of pearl-white. Their calls and songs are equally beautiful and utterly captivating. An unmistakable holler that is equal parts harrowing and hallowed. The tune of the Loon echoes off the water, inundating the landscape and resonating deep in the soul of all who hear it; a call of the wild. A ringing wail, half mourning cry and new morning’s sigh, a requiem for our wilds of past and an exaltation for those that still last.
This week for Flora and Fauna Friday we’ve got a pair of native clumping grasses, Saltmeadow Cordgrass (Sporobolus pumilus) and Sand Cordgrass (Sporobolus bakeri).
Both Saltmeadow Cordgrass and Sand Cordgrass are perennial native grasses found along the extreme coast of South Carolina, to include here on Edisto Island. Saltmeadow Cordgrass is a widely distributed plant, being found across the entire eastern seaboard of the United States. Sand Cordgrass is far more limited, mainly residing in Florida northward to Charleston, SC. The two species look very similar. Both spread through their roots but grow as clumps rather than individual stems. They form large, three to five foot high, dome-shaped clumps with their arching grass blades, which have emerald-green foliage fading to straw-yellow with age. Even the flowers of these two species are similar in appearance, a dozen branches of florets stacked tightly like books on a shelf, similar to other Cordgrasses (formerly members of Spartina). One of their few easily described physical differences is that these floral branches in Saltmeadow Cordgrass tend to be more perpendicular to the stem, whereas those of Sand Cordgrass are held upward to nearly parallel. But of course they vary and overlap! In my experience the two are best told apart by their differing preferred habitats and the gestalt of the whole plant.
I find Sand Cordgrass to be a bigger plant overall, often growing chest to chin-high as a well-defined clump with more yellow foliage. Sand Cordgrass is more of an upland plant, growing on banks, dikes, and wetland edges on sandy, moist soils. It also doesn’t tolerate regular saltwater intrusion all that well, preferring to grow in the brackish and freshwater reaches of tidal systems. Here on Edisto Island, I mainly see it on the northwestern corner of the Island, where the freshwater influence of the South Edisto River and the plethora of old dike-works create pockets of suitable habitat. It is far more abundant west of Edisto Island, in the heart of the ACE Basin and around Beaufort. Sand Cordgrass is a wonderful native landscaping plant and does well in wide array of use cases in coastal towns and neighborhoods, but prefers subtropical climes.
Saltmeadow Cordgrass trends more toward a knee to waist-high clump and is more prone to forming loose clumps and monocultures. Saltmeadow Cordgrass is highly tolerant of irregular saltwater intrusion but can’t persist in the true saltmarsh. I most often encounter it on marsh islands, tidal ditch banks, tidal floodplains, and wetland swales where a shallow water table flows into the marsh. Think of it as growing within the king tide line. Places that see a high salty tide once a month or less, but not with daily consistency. Here on Edisto Island, these places, and consequently Saltmeadow Cordgrass, are generally few and far between, but fairly common on Little Edisto Island. Overall in the Lowcountry, Saltmeadow Cordgrass does well as a landscaping plant on the banks of brackish ponds, floating wetland islands, tidal wetlands, and sandy marsh edges.
This week for Flora and Fauna Friday it’s the Lowcountry’s local marsh sparrow, the MacGillivray’s Seaside Sparrow (Ammospiza maritima macgillivraii).
Within the winter’s salt marsh the blackbirds linger and grackles gallivant, rails scurry and wrens bound, all beneath the watchful eye of hovering harriers and ospreys. But between them all resides a trio of songbirds, scarcely seen and rarely heard, who call this cordgrass kingdom home, the marsh sparrows: Seaside Sparrow (Ammospiza maritima), Saltmarsh Sparrow (A. caudacuta), and Nelson’s Sparrow (A. nelsoni). Within their ranks one can find a special lineage, the subspecies MacGillivray’s Seaside Sparrow (A. m. macgillivraii), who calls the marshes of the Sea Islands home year-round.
The MacGillivray’s Seaside Sparrow is a large sparrow with a heavy bill and tattered tail that’s dyed in dusky, dark plumage. Soot-stained gray shades its body, dark walnut-brown colors its wings, an occasional chestnut wash livens its breast and flanks, while a white patch under the chin and a lemon-yellow eyebrow add the only sharp contrast to its feathers. Their call is a high metallic “tink” and their song a three-part verse, first a cricket-like chirp, then a lower two note warble, and finished with a dry, trailing buzz. Their vocalizations are made softly and steadily, easily becoming buried in the cacophonous din of a windswept spring marsh, already saturated in blackbird song. MacGillivray’s Seaside Sparrows live their lives within the saline and brackish marshes of South Carolina. There they forage on seeds, insects, and other invertebrates. In spring they head up river to nest in higher, more tidally stable marshlands. In winter, they head towards the coast, to hunker down on marsh islands in the thermal stability by the sea.
Seaside Sparrows, of all subspecies, and the Saltmarsh and Nelson’s Sparrows are facing tremendous pressure. The Saltmarsh Sparrow is currently under review with the US Fish & Wildlife Service for listing under the endangered species act as threatened. The MacGillivray’s subspecies of the Seaside Sparrow was petitioned for listing in 2018, but ultimately not protected. The Dusky subspecies (A. m. nigrescens) of Florida already went extinct in 1987. Historic wetland draining and alteration, ongoing coastal development, more extreme tide cycles, and rising sea levels are squeezing marsh sparrows from all angles to dwindle their populations. Here in South Carolina, all three species overwinter in our salt marshes and rely heavily upon marsh islands and hammocks for refuge during king tides. As seas rise and the number of king tides increases, these marsh islands become ever more critical, and ever more scarce.
This underscores the priceless value of the protection, restoration, and management of tidal wetlands in the Lowcountry of South Carolina for the survival of these three sparrows, as well as every other species that depends upon our estuaries. Protecting marshlands, marsh islands, and the marsh migration spaces abutting them ensures the highest quality marsh habitat will persist into the future. Restoring historically drained or bermed marshlands will improve the condition of marsh migration space and offers the opportunity to create future marsh islands. Smart management and maintenance of existing tidal impoundments, particularly rice impoundments, will provide bastions of stability and refuge during tumultuous times and tides. Although the futures of our marsh sparrows look bleak, we’ve pulled species back from the brink under bleaker circumstances. Here at the Edisto Island Open Land Trust, we’re doing our part, and we’re always looking forward to how we can forge the brightest future we can on Edisto Island, one plan, one person, or one parcel at a time.
This week for Flora and Fauna Friday it’s our most widespread Lichen in the Lowcountry, Bushy Beard Lichen (Usnea strigosa).
Beard Lichens can be found in humid forests all throughout the Southeast. This genus, Usnea, contains a multitude of similar looking species that range around the globe and with several found here on the Sea Islands of South Carolina, including Bushy Beard Lichen (U. strigosa), Coastal Beard Lichen (U. evansii), Horned Beard Lichen (U. subscabrosa), and Cryptic Beard Lichen (U. endochyrsea). Today I’ll be focusing primarily on Bushy Beard Lichen, our most common species. Beard Lichens are epiphytes, growing on the bark of trees, particularly small branches and buttresses. Like other epiphytes, they cling to bark purely for support. They absorb their nutrition from the air and rainwater that washes over them and produce food through photosynthesis.
I often find Bushy Beard Lichen growing in floodplains, bottomland forests, and maritime fringes. Its fungal façade is a pale platinum-white with a subtle greenish hue and takes on a fluffy, beard-like form. This lichen’s body is finely divided into roughly inch-long feathery tendrils to increase its surface area, for efficiently gathering both light and water. Bushy Beard Lichen often has many small circular discs, embedded in its body. These structures are called apothecia and are its primary spore-bearing structures. Its “mushrooms” if you will. Their abundance helps you to tell Bushy Beard Lichen apart from other members of the Usnea genus, as most of our other species reproduce with different spore-bearing structures and rarely have the dish-like apothecia in number.
Because of their epiphytic nature and reliance on rainwater and humidity for nutrition, Beard Lichens, and other similar epiphytic lichens, are very sensitive to poor air quality and pollution in rainwater. You won’t find them growing above a well trafficked road, due to car exhaust filtering through them, or in urban areas, with increased acid rain and smog. But on Edisto Island, they abound, high above, on the boughs of oaks in the peaceful woodlands along our backroads, and at arm’s reach, in the windswept margins of our maritime forests.
On an aside, I want to talk about Lichens in general for a bit and add a disclaimer to the above. I’ll be the first to tell you, I don’t much about Lichen taxonomy. To be frank, almost no one does. Lichens are a fascinating and strange life form, referred to as a compound organism. They are a fusion of a photosynthetic microbe, an alga or cyanobacteria, and a specialized fungus, with the fungus wearing the proverbial pants in this relationship. This arrangement is similar to how corals operate, but far more advanced and intertwined. The fungus has ostensibly turned its body into a greenhouse and is growing a special strain of photosynthetic microbe within its body. Complex symbiosis and natural co-evolution like this is quite amusing to ponder upon, but that’s a rabbit hole and monologue for a different day. In regards to Lichens, this makes studying and discerning different species of Lichen very complex. Since there are multiple organisms acting as one, what qualifies as the “species” becomes nebulous and breaks down most taxonomic definitions of what a species is. My above account of Bushy Beard Lichen (Usnea strigosa), I can tell you, for a fact, is really a description of a species complex containing at least one other extremely similar looking species, Cryptic Beard Lichen (U. endochyrsea), but likely also several more and probably something currently undescribed. Point being, biologists ain’t figured these things out yet! Advances in gene sequencing and phylogenetic techniques are coming along swiftly these days and more and more attention is being put to topics like this with each passing year. So maybe, in the next few decades, we’ll finally have a solid idea of the biodiversity of Lichens and hopefully some kind of handle on how to even define symbiotes like these taxonomically.
This week for Flora and Fauna Friday, we have the bane of marsh birds, the wraith of the marsh, the Northern Harrier (Circus hudsonius).
The chill of morning lingers in autumn’s wet dawn air. Fog rising, cold steam, from the waking engine of the salt marsh, a metaphor which reflects the serenity of your awoken mental haze, that pleasant AM daze, before the anxious machinations of mind, or marsh, can commence. But then, like a ghostly train of thought steaming on return from yesterday, an eerie specter tunnels into sight. Piercing sunken eyes and pallid plumage, cutting through the fog on silent wings mere feet above the marsh, a Northern Harrier coasts by on his breakfast commute, delivering a shudder of silence to the morning marsh.
The Northern Harrier is a mid-sized hawk, very similar in size to the Red-shouldered Hawk (Buteo lineatus) but bearing many unique physical features. Their tail is long and broad and so are their wings which, held upward in a slight dihedral, offer perfect aerodynamics for controlled gliding. Males are colored a dingy platinum-gray above and cloud-white below, with wingtips and trailing edges stained slate-black. Females are a walnut-brown above and dyed a rust-orange below, with a speckled checkerboard of black and white on their flight feathers. Both sexes have a long banded tail, affixed above to an unmistakable white rump. Like most raptors, their large eyes give them great vision for hunting. Yet, Harriers have honed another sense. Northern Harriers have excellent hearing and even possess a feathered facial disk, turning their face into a parabolic reflector and giving them a distinctly owl-like appearance. They also have elongated legs, making them stand taller than other raptors their size. Both these features give them a subtly uncanny appearance compared to other hawks.
A Harrier’s keen senses, long legs, and controlled gliding flight pattern come together to form the backbone of their hunting strategy. Northern Harriers cruise, silently and with infrequent wingbeats, on the short air thermals rising off the tops of sunbaked marshes and fields. From just a few feet up, they scan the grasses and reeds for movement while listening for motion and vocalizations, before reeling back and plunging straight down on unsuspecting prey, reaching their long legs through the grass to grasp. Northern Harriers primarily feed on songbirds within the salt marshes of the Sea Islands but will eat just about anything of suitable size, particularly rodents, small rails, lizards, frogs, and large insects. The Northern Harrier is found throughout North America but calls the marshes of Edisto Island home in fall and winter. Here they can readily be seen patrolling the vast mashes of the Dawhoo River along National Scenic Byway 174.
