Zebras, Spiders, and an Interesting Vine

August 7, 2015.  We had two-and-a-half inches of badly-needed rain yesterday afternoon at my house in Columbia, but it’s obvious not a drop fell here at the park, only fifteen miles away. It reaffirms that summer rainfall in South Carolina is local.

Since my last visit five days ago, I see that the squirrels have begun feeding on green pine cones, as indicated by the leavings scattered over the handrails and decking of the high boardwalk. I’m  impressed with any animal that can take on and dismember the hard, spiny cones.

Five-lobed cucumber vine, Cayaponia quinqueloba.

I find an interesting vine growing on the trail near Wise Lake. The bright red, oblong fruits, about three-fourths of an inch long, stand out like beacons against the green foliage and grab my attention first. They are doing their job as color attractants in order to get birds to eat them and disperse the seeds (John Nelson, curator of the A.C. Moore Herbarium at the University of South Carolina, reports that they have a very bitter taste). The red color and bitter taste may be an indicator of a high quality food for migratory birds which will soon be passing through the Congaree in large numbers. High quality bird fruits typically have a bitter or sour taste and are high in fats, rather than sugars, and enable migratory birds to undertake their arduous fall migrations that take them thousands of miles away from their breeding grounds in North America. Some other high quality bird fruits now ripening in the swamp include spicebush, Virginia creeper, and swamp tupelo.

The vine is five-lobed cucumber, Cayaponia quinqueloba, a tropical species with close relatives in South America. It is a member of the famous Cucurbitaceae family which includes such notable representatives as squash, cucumber, gourds, pumpkins, cantaloupe, and watermelon. All of these are vine plants, and botanically speaking, the melons, gourds, cucumbers and squashes themselves are called a pepo, one of my favorite botanical terms. A pepo is defined as a soft fruit, without internal partitions or septa (as found in citrus fruits), surrounded by a hardened rind. Like all family members, five-lobe cucumber is pollinated by bees, although some botanists think in their original tropical haunts they were pollinated by bats.

My interesting vine is one of the thirty plus species of vines found at Congaree, more than any other national park.

After crossing the bridge over a very dry Hammond Gut, I walk for the first half mile on a southwest bearing that takes me through a series of ridges and swales, the latter being old river channels from thousands of years old, the former, old river banks. This is a nice section of old-growth forest dominated by large sweetgums, green ash, and sugarberries. The ground cover, unfortunately, is dominated by lush clumps of exotic Japanese stilt grass, Microstegium vimineum.

Stilt grass, Microstegium, has unfortunately become widespread as a ground cover at Congaree.

I get a whiff of bananas and see the source, a ripe fallen pawpaw, partially chewed by squirrels or rodents. It’s the first fruit I’ve seen this morning, despite walking by hundreds of pawpaw trees.

As I get closer to the river, the ridge and swale topography merges into flat terrain dominated by even-aged, medium-size sweetgums with a few scattered cherrybark oaks. A forest stand dominated by even-aged sweetgum like these suggests the possibility of an antebellum clearing of some sort, possibly an agricultural field or other such opening.

I come out at Pearson’s Pond, probably named for Philip Pearson, one of the early surveyors in Richland County who surveyed some of the first Congaree land grants before and after the Revolution. The pond has not had any water in it for four or five months, and the bottom has been thoroughly chewed up by rooting pigs. The trees are mostly small to medium-sized water tupelo and red maple. I see no large rotten stumps of virgin cypress that are characteristic of many other ponds and sloughs in the park.

The next pond to the west of Pearson’s is Duck Pond, named by Harry Hampton. It has a number of large old stumps that appear to be water tupelo, all of which were cut at ground level rather than above the buttress as most cypress were. I don’t think water tupelo had much commercial value a hundred years ago when the virgin cypress stands were being cut and don’t understand  why they would be cut at ground level as it made for extra work with little economic return. The insides of the old stumps are recessed a foot or more below ground and filled with sediment that has settled in over the years.  This could explain why the old stumps are now at ground level: a hundred years ago the stumps may have been two feet above ground level.

The north loop of the ten-mile River Trail runs along the western edge of Duck Pond. It is one of the most unused trail sections in the park, since most hikers prefer to stay on the south section and get to the river quicker.

A hard to see spiny-backed spider in the middle of this photo by John Grego.

I have been walking for much of the morning and early afternoon through numerous spider webs, always at face height. Many of these webs belong to Verrucosa arenata, the triangulate orbweaver or “arrowhead spider,” in reference to the white triangular patch on its abdomen. Other webs belong to spiny-backed spiders in the genus Micrathena. I see not a single golden silk spider today.

As I attempt to unwrap one particularly irksome web that has ensnared me, accompanied by low curses, I see a zebra swallowtail butterfly, with notably long tail streamers, flitting through a clump of sunlit pawpaws. I have to ask myself, why don’t butterflies get caught in spider webs? I know some do on occasion, but still, you’d think there would be a lot more trapped in webs out there.

I watch the zebra as it flits from one pawpaw to another, pausing briefly on the leaves as if wanting to lay eggs. It comes closer and lights on the edge on one leaf and bends its abdomen underneath the leaf, then quickly flies off. I walk over, look under the leaf, and sure enough, find the round, light green egg she just laid, about the size of a pin head. Despite the abundance of both pawpaws and zebra swallowtails at Congaree, I have yet to see my first zebra caterpillar.

It is early afternoon, clouding up a bit, and I hear a distant rumble of thunder.  On the way back I walk the last twenty minutes in a light rain but barely get wet since a lot of it is intercepted by the dense canopy overhead.

Possum on the Half Shell

August 2, 2015.  I decide on another night visit to the park to take advantage of a day-after full moon. Unfortunately, it does not rise until 9:15 and has still not cleared the trees by the time I leave the park thirty minutes after midnight.

I start out on the high boardwalk. A light rain fell earlier in the evening but was not enough to even wet the boardwalk where the canopy overhangs it. The air is thick with humidity.

Shortly after I get on the low boardwalk, I hear faint, clucking, bird-like sounds and look down just in time to see an armadillo tail disappear under the boardwalk. The odd-looking animal, appearing like a cross between a reptile and a possum, shortly emerges and scurries along the ground next to the boardwalk. It’s the latest in a series of exotic fauna that has invaded the park in recent times, starting back in the 1980’s with feral swine, the 1990’s with coyotes, and the early 2000’s with nine-banded armadillos (I don’t count beavers that started showing up in the 1990’s since they once occurred here naturally). Makes me wonder what’s next? They say nutria, a South American rodent similar to the muskrat and introduced to Louisiana in the 1930’s, is heading this way.

I wonder too what impacts the “possum on the half-shell,” as some call the armadillo, will have in the Congaree? They are mostly insectivorous, feeding on ants, termites, beetles, and grubs, as well as other invertebrates such as earthworms, millipedes, centipedes, snails, and slugs, and in floodplains like the Congaree, even crayfish. But they also have a strong generalist streak, and are probably not above feeding opportunistically on ground-nesting bird and turtle eggs, salamanders, small snakes, and skinks and lizards. They will at times feed on plant material such as seeds, berries,  nuts, and even occasionally mushrooms. Their food habits overlap a good bit with feral swine and between the two could be having negative impacts on what I call Congaree’s “log fauna.”

In the modern landscape, armadillos appear to have few natural predators except for automobiles, which kill thousands every year in their now widespread range, a range that goes as far west as Nebraska, and north to Indiana, with expected incursions eventually into Pennsylvania, New York and New Jersey. The one thing that may eventually limit their expansion is the lack of insulation, which makes them vulnerable to cold winters. They don’t hibernate but dig burrows for security and to escape the elements. In the Congaree I often see armadillo burrows in the large mounds of root balls (tip-up mounds) created by fallen trees. Coyotes and bobcats appear to be their only predators in the swamp. Armadillo flesh is consumed by some humans and supposedly tastes like pork (rather than chicken). They are well known for having identical quadruplets and the only other animal besides humans to contract leprosy.

Armadillos are adaptable to a wide variety of habitats and seem well-equipped for floodplain living. They can hold their breath for long periods of time, have been known to cross water bodies by walking on the bottom, and can make themselves buoyant by partially inflating their bodies. And of course floodplains provide an enormous variety and abundance of armadillo foods. However, during floods, armadillos, like many swamp critters, have to tough it out and too much flooding probably results in heavy armadillo mortality.

I stay on the low boardwalk and make my way to Weston Lake. At Tupelo Alley I find another armadillo next to the boardwalk. This one also hurries out of my way and runs off into the now-dry slough that runs into Weston Lake.

A green (bronze) frog, a smaller relative  of the bullfrog and very abundant at Congaree. By John Grego.

I arrive at the lake overlook at 10:30 to a chorus of green frogs (aka bronze frog), if that’s the right term for their monosyllabic, banjo-like calling; katydids and crickets are serving as back-up. I see only a handful of lightning bugs tonight, mostly around the high boardwalk back near the bluff line at the visitor’s center. The still-rising, orange-yellow moon is mostly hidden behind the thick canopy foliage. I sit for nearly an hour without hearing anything else except the occasional splash of a fish and a few, far off, one-note barred owl calls. I listen, in vain, for the faint laughing of the Weston Lake sturgeon rider.

I return via the Sims Trail and high boardwalk. Just before arriving on high ground, the beam of my headlamp picks out a bright green object on the boardwalk handrail. At first glimpse I think it’s a leaf, but a second look shows it to be the caterpillar of a tiger swallowtail butterfly. It’s about an inch-and-a-half long with the characteristic small yellow eye spots near the front of the body. It obviously fell from an overhead leaf, where it was much more camouflaged, and secure, than here on the handrail.

Moonrise at Dawson’s

July 30, 2015.  Moonrise this evening is 7:45, one day shy of being full, and I decide on a moonlight paddle on Cedar Creek. When I arrive at the landing at 8:45 the katydids have already started singing, and a few cicadas are still calling at the end of the day shift.

Katydid

Cedar Creek is low, 1.9 feet, and my paddle touches bottom in places. The creek bottom is filled with old rafts of logs that didn’t make it to the mill a century ago. Presumably they were too green, and heavy, to float. The logs appear to be sound, but many have been partially exposed to the air during droughts and low water and may not have much value as recovered wood.

The shallow creek has a slight fishy smell; it disappears once I reach the deeper Dawson’s Lake. Every once in a while I also detect a faint fragrance of something almost sweet, an odor I periodically smell during the growing season in the swamp but still haven’t been able to pin down its source.

The creek edge is bright with the reflected eye shine of wolf spiders, some of which are a nice size. They are on tree trunks and fallen limbs and logs as well. I see a snake swimming along the edge and paddle closer for a better look. It’s a small cottonmouth about eighteen inches long. It reminds me of how vulnerable kayakers are to a rare but possible poisonous snake bite coming from a swimming cottonmouth since our arms are only inches above the water. Another heads- up situation for kayakers is paddling through shallow sloughs and guts full of logs and debris, places that make ideal cottonmouth resting places. I somehow feel a lot more exposed being at eye level to a cottonmouth rather than looking down at if from five feet, nine inches, away.

Up ahead and coming from the crotch of a water elm overhanging the creek is a bright eye shine that belongs to a half-grown raccoon. It keeps an eye on me as I pass under it.

I make it to Dawson’s at 9:30. The nearly-full moon has finally cleared the trees but is partially obscured by haze and light overcast. Green frogs are calling regularly as is a single green treefrog. The latter’s call, despite coming from a much smaller animal than the green, is loud in the nighttime stillness.

I hear a faint sound coming from the partially submerged top of a nearby large fallen tree lying horizontally in the lake with most of its trunk and thick crown above water. It sounds like the whimper of a child. I paddle over to investigate, and a beaver swims by within six feet of the kayak. It turns and goes back into the cover of the fallen tree, where I see it raise out of the water a little and give the whimper-like call. I now hear another faint sound, almost like something gnawing on wood. Then a small beaver, about the size of a gray squirrel, swims from the tree and right up to the boat (perhaps my headlamp has confused it). It turns and swims around a bit in open water before going back to the security and safety of the tree.

I stay at Dawson’s for nearly an hour. The beavers go silent, and about the only sounds are coming from frogs, the periodic splash of fish, and katydids. I only hear one or two barred owls make brief, one-syllable calls. The only lightning bugs I see are back at the landing.

I get back to the landing at 11:00. On the drive home, I see the moon shining in glorious brightness, the haze and overcast left behind.

Good To Be Back

July 27, 2015.  It has been six weeks since my last visit to the swamp, time occupied by a detour to Maritime Canada, where I was sleeping under two or three blankets at night and wearing a fleece pullover in the morning. The swamp is so different from Canada that I may as well have been on another planet.

It has been hot and dry during my absence. For my six-hour visit today the only water I found was in Cedar Creek, and there wasn’t much in it (the gauge is reading 1.9 feet). The mosquitoes are absent as well, but a few deer flies are still lingering on. It is a reminder of the regular clash of reality versus myth for southern river swamps – the public image of quicksand, biting insects, poisonous snakes, alligators, and other perils and dangers. I daresay that just one campground in Newfoundland and Nova Scotia has more mosquitoes than now found in the entire Congaree National Park.

There was obviously a recent, violent windstorm as indicated by three oaks snapped off by the high boardwalk on the edge of the floodplain. They all fell pointing north-northwest, indicating the wind coming from the opposite direction. Within the floodplain two large loblolly pines by the boardwalk were also snapped off by the same storm (fortunately neither hit the boardwalk). And several large limbs are on the ground. No doubt it would have been a frightening experience being caught in the middle of such violence and mayhem.

Swamp milkweed, Asclepias perennis.

I leave the low boardwalk and walk west. About the only thing blooming right now is swamp milkweed growing in the muck swamp. I continue on a westerly course, in what I call “low swamp” (referring to elevation and not canopy), a transition area between the muck swamp to the north and the higher bottomland forest to the south. The latter is demarked by an abrupt line of switch cane that runs almost like a straight line along its edge. The low swamp consists primarily of green ash, laurel and willow oak, overcup oak, red maple, and American elm. There is no undergrowth and you can easily see three or four hundred feet in front of you. The ground floor is bare, with scattered patches of luminescent green sedge and strewn with downed limbs and logs. The trees for the most part are not that big, perhaps due to the thick, hard, clay soil that contains little oxygen to support root growth.

Golden silk spider wrapping up a cicada for lunch.

There are a lot more spider webs out than when I was last here, on June 11, and I see some impressively large female golden silk spiders. The open visibility also allows me to see a doe deer two hundred feet away. She is looking at me intently, ears flared like open car doors, and tail twitching. She can’t quite figure me out but doesn’t like what she sees and snorts with displeasure. She actually walks slowly my way for a better look (or smell) and then makes a side step and circles around me, all the while snorting and checking me out. Then I see a yearling buck coming behind her with six-inch spike horns in velvet. The buck is not as alert as the doe and isn’t aware of my presence. Finally the doe has had enough and turns to retreat, but the buck goes in front, and they bound off together.

I make it as far west as Big Hurricane Island on the north side of Cedar Creek. It’s not a true island, being surrounded on three sides by muck swamp and Cedar Creek on the south and west. I have a hunch that the “island” made a good cowpen during antebellum times because of the high ground and being surrounded by water for much of the year. This could explain the origin of the large pines on its southern and western ends since much of it would have been cleared and open enough to grow pine trees after being abandoned as a cowpen.

Cedar Creek at 1.9 feet.

The island got hammered by Hugo, especially in the middle. Parts of it are still nearly impenetrable with a jungle of grape vines and thickets. The hurricane knocked over or snapped off a good number of pines. Some of the survivors have since succumbed to insects and “old age,” and like other loblolly pine stands in the floodplain, there are no seedlings or young trees to replace the dead and dying old pines.

It is now early afternoon, warm and humid as I make my way back. Today’s high is supposed to be in the upper 90s. Without the cooling effects of the dense overhead canopy to block most of the sun’s heat, I would probably not last more than an hour out here.

I return via the bottomland hardwood community closer to Cedar Creek, which means walking through switch cane, where I flush a yellow-billed cuckoo. It flies to a low-hanging, bare limb ten feet off the ground. It’s unusual to see one close to the ground like this. The bird is in hunting mode, and provides good viewing as I watch him for fifteen minutes. He acts almost like a squirrel as he ambles over limbs and vines, using his feet rather than his wings to search for food. His head turns constantly as he peers intently while moving, looking for any movement that may betray a victim. For a brief moment he acts like a bird and makes a short hover flight to the bottom of a leafy twig and snatches at something, but I can’t tell if he was successful or not.

I turn a few logs; one has a patent leather beetle, a millipede, and a good-looking three-lined salamander.

Three-lined salamander.

Essay: Demise of the Canebrake

Many accounts by the early naturalists and travelers that explored the South mentioned the existence of dense canebrakes found along coastal rivers and swamps. Some of these canebrakes  covered hundreds, even thousands of acres, and extended for miles along river banks and channels. Indeed, these canebrakes were one of the most distinctive features of Southern riverine landscapes that extended well into the Piedmont, almost to the Foothills. Greenville’s Reedy River for example, gets its name from the abundant stands of giant cane, or river cane (Arundinaria gigantea), that were found growing there by early white settlers. In October, 1907, President Theodore Roosevelt spent two weeks hunting bears in a Louisiana bottomland forest that featured extensive stands of cane and from which he later wrote an article, “In the Louisiana Canebrakes.”

It is no accident that elk and bison that formerly occurred in the Southeast were often associated with canebrakes and cane meadows. This woody member of this grass family provided highly nutritious forage for a variety of browsing animals, a fact not lost on the pioneers who allowed their cattle access to cane stands under the free-range system. Settlers also realized that cane grew on some of the most fertile and productive agriculture soils. However, between overgrazing, clearing, dam construction, channelization, hydrology changes, both excessive burning as well as the exclusion of fire (cane apparently flourishes with some periodic burning that helps rejuvenate the stands and eliminate competing vegetation), and other factors, the extensive canebrakes of the South have all but disappeared, to the extent that they are now considered one of the most endangered plant communities in North America.

Switch cane is a common bottomland species at Congaree National Park.

When I was a youngster, the botanists considered our native cane, sometimes called bamboo, to be one species, even though earlier accounts classified them as two species: river or giant cane, and the smaller switch cane, A. tecta. But as what sometimes happens in taxonomic full circles, the experts have again split them back into two separate species, switch cane and giant cane. Recently a third species of cane, A. appalachiana, hill cane, found growing on hillsides in the southern Appalachians, has been described in the botanical literature.

Most native river cane is about an inch or inch and a half in diameter and fifteen to eighteen feet tall. It is the classic fishing pole cane of Americana and should not be confused with exotic and aggressive bamboo which may be four inches in diameter and thirty feet tall.

I have never seen a canebrake approaching anywhere near the sizes of those mentioned in the early literature. The ones I’ve run across in South Carolina have consisted of only scattered specimens, or small stands. I do remember years ago a stand of giant cane on the Francis Marion National Forest, and several stands in the Wateree and Upper Santee Swamps. The only giant cane of any extent I know of at Congaree is found on some narrow ridges at “Little Buckhead,” east of the Highway 601 causeway.

Cane was apparently much more prevalent at Congaree in the middle-1700s when the first land grants were made; it wasn’t uncommon for the surveyors to describe the land surrounding the grant as “all cane swamp.” That’s a tantalizing description since we don’t know exactly what “all cane swamp” meant – was it, for example, switch cane, or did it mean dense canebrakes of giant cane? It does fit the pattern noted by many, however, of cane being more abundant during historical times.

The largest canebrake I’m aware of in modern times occurred along the Ocmulgee River bottoms near Macon, Georgia, as noted by biologist Brooke Meanley in his book, Swamps, River Bottoms and Canebrakes. In the 1940s, he estimated one of these canebrakes covered a square mile (640 acres) with cane stems averaging fifteen to twenty feet high and maximum diameters of an inch and a quarter. This must have been an impressive sight to see. Meanley reported these stands were still extant in the 1970s; some of them later became part of the Bond Swamp National Wildlife Refuge, established in 1989.

Canebrakes are established primarily by vegetative means through the spread of underground rhizomes. Years may go by before the plants eventually produce flowers and seeds – after which they all die. The seeds are highly nutritious but lack much dormancy.

I was initially under the impression that the lack of canebrakes at Congaree was related to excess shading from a dense overstory. After Hurricane Hugo swept through in 1989, creating  numerous holes and gaps in the canopy, I anticipated that some of these gaps would fill in with river cane. This did not happen, however, presumably because there was no available seed source, nor enough river cane to provide vegetative reproduction through rhizomes. This may explain why so many clearcuts found in today’s riverbottom forests fail to create canebrakes (and fill in with exotic privet instead).

What did respond after Hugo, albeit slowly, was switch cane, already in place and widespread at Congaree. This species seems to be quite different, ecologically, from river cane. It tolerates higher water tables and grows in low places and flats throughout the interior of the Congaree, and not just along the river front. It also appears to tolerate more shading than river cane. Over the past twenty-five years since Hugo I have noticed a significant amount of switch cane growing in places where it was sparse and uncommon before.

Something else going on with switch cane is that in places where the Congaree overstory suffered heavy hurricane damage, notably the park’s east end, the switch cane in places has gradually gotten taller, five to six feet rather than the usual three-and-a-half. The stems are still pencil-sized.

Negotiating a thicket of tall switch cane in the park’s East End.

Are the giant canebrakes of yesteryear an artifact of human origins? It is no coincidence that many of them were found on old, abandoned fields and clearings along the riverbank that had originally been created by Indians for their crops and gardens. The beginnings of intensive Indian agriculture in the Southeast, consisting of the three “sisters” – corn, beans and squash – dates back to around 1000 AD. Indian farming eventually led to the rise of permanent villages and towns and a corresponding increase in Indian numbers, estimated by some sources at 1.7 million at the time of first European contact in the Southeast. The rapid decline of Southeastern Indian populations after first contact, due primarily to infectious diseases but also to warfare and civil strife, resulted in thousands of acres of abandoned riverfront fields that eventually filled in with extensive canebrakes. Canebrakes were probably always part of bottomland hardwood native flora, but likely less extensive before Native Americans arrived on the scene and created ideal conditions for it to thrive and become established in American folklore.

This 1747 land grant on the Wateree River near Camden shows a former Indian Old Field. It became known as Gibson’s Neck, later Friends Neck.

Peterson’s Challenge, Part 2

Five years after conducting my last breeding bird census at Congaree, one of the most powerful hurricanes to hit the South Carolina coast in more than a century created catastrophic changes in much of South Carolina’s forestland. Hugo’s powerful winds passed through central South Carolina, and Congaree National Park, early on the morning of September 22, 1989, with sustained wind gusts of over 90 miles per hour.

It was later in October when I finally got down to the park and investigated the damage to my bird census plot. My initial reaction was shock and disbelief at all the daylight streaming through a formerly closed canopy. Downed trees, limbs, and woody debris were everywhere and at times I wasn’t even sure I had the right location. Based on my previous vegetation survey of the plot, I determined that in one night Hurricane Hugo knocked down sixty-eight trees a foot or more in diameter on my twenty-acre plot; most significantly, twelve of the sixty-eight were three feet in diameter or more.

A large Hugo-downed sweetgum on my bird census plot.

In May, 1991, only a year-and-a-half after Hugo, I was again studying the bird population of my Congaree research plot, but using different methods for different purposes. And I would notice an immediate change in bird numbers and species composition from my earlier census work of just seven years ago.

I began a MAPS (Monitoring Avian Productivity and Survival, a nation-wide program created by the Institute for Bird Populations at Point Reyes Bird Observatory in California) bird-banding station at my Congaree bird plot in the late spring of 1991 and continued it until 2004 (2003 was scrubbed due to excessive flooding). At the end of the first 1991 MAPS field season, in August, we had banded a total of 112 breeding-season birds representing 22 species. It was noteworthy that Carolina wrens were nearly twice as abundant after Hugo as before; white-eyed vireos were nearly three times as abundant; and the hooded warbler, five times as abundant. Just as significantly, three species never recorded before Hugo – indigo bunting, Kentucky warbler, and Swainson’s warbler – were banded on the plot in 1991.

The indigo bunting was found on the census plot only after Hurricane Hugo.

All six of the above species were birds of thickets and dense cover, the so-called edge species mentioned by Roger Tory Peterson. This was no surprise as the bird plot had an entirely different look after Hugo as compared to before: the former dark, dense canopy had been replaced by a much more open canopy and the vegetation-free understory with thickets and cover scattered throughout the twenty acres (and it was amazing to see how quickly the dense cover grew up in only one growing season after Hugo, from 1990 to 1991).

It was noteworthy to follow the trends of three edge species over the next thirteen years: hooded warbler numbers peaked out the summer of 1992, when nineteen were banded; their numbers started declining noticeably after 1995, so that by 2004 there were only two banded on the plot. Trends for white-eyed vireos were similar: their numbers peaked at eleven banded in 1995 and only two banded in 2004. The much-less numerous Swainson’s warbler was represented with a maximum of four birds banded in 1994, while only one was banded from 2000 to 2004.

The uncommon Swainson’s warbler was another species only found after Hurricane Hugo.

What all of this was telling me was that vegetation growth at Congaree was so fast that within eight to ten years after the hurricane, the canopy had closed to pre-Hugo conditions. This resulted in so little sunlight hitting the forest floor that the sun-loving thickets and other dense cover thinned out to the point that the edge birds could no longer use them.

I came to the conclusion that bottomland hardwood forests of the South, nearly all of which are within striking distance of hurricanes, were “managed” under pre-settlement conditions by recurrent strong winds, primarily from hurricanes, but on a smaller scale, by tornadoes and strong wind storms. Winds of this magnitude were needed to open the canopy sufficiently to allow the development of large enough thickets favored by bird edge species.

It appears to me that Congaree, and likely many other bottomland hardwood forests of the South, go through decades of hurricane “dormancy,” where a closed canopy limits the development of thickets, followed by a shorter period where an open canopy created from a passing storm allows the growth of thickets and edges. The birds that use these early-successional habitats must, by nature, be nomadic enough to take advantage of a shifting, transitory habitat.

Hooded warblers were five times more abundant after Hugo.

A caveat here is that hurricane damage on our bird study plot was characterized as moderate (although it certainly didn’t seem moderate at the time). There were some areas in the park, however, that received very heavy hurricane damage – where nearly every overstory tree was felled by strong winds – in effect creating small, natural clearcuts of a few acres or less. Recovery of these stands to pre-Hugo conditions will obviously take many, many decades.

Essay: Peterson’s Challenge

For much of June and July, 2015, I made a detour from Congaree and visited Canada’s magnificent martime provinces. I will pick back up with Congaree Journal on July 27th but in the interim will post a couple of essays that I hope you will find interesting. Here is one I’m calling “Peterson’s Challenge.”

In March of 1937 Roger Tory Peterson, destined to become the most famous ornithological figure of the twentieth century, and Lester Walsh, an official with the National Audubon Society, made a ten-day float trip down nearly the entire length of the Santee River. They were searching for some of the last ivory-billed woodpeckers left on earth, ivory-bills that had recently been discovered in the depths of the lower Santee River Swamp. Although they failed to find the great woodpecker on this trip (Peterson did manage to see it five years later in the famous Singer Tract in northeastern Louisiana), both men came away mightily impressed with the extensive old-growth hardwood forests of the Santee bottoms.

Peterson’s experiences in these two large southern river swamps, both faced with imminent destruction (by 1942 much of Santee’s old-growth forest was under thirty-five feet of water from the Santee-Cooper Hydroelectric Project, and all of the Singer Tract was cut over by the end of World War II), led him to urge that “someone should start taking bird censuses in an original river-swamp habitat before it is all gone.”  Peterson suspected that bird populations would be greater in original forest than mature second-growth because the “trees of virgin growth were so large and widely spaced that they formed their own edge.”

Peterson’s appeal fell on deaf ears, not due to a lack of interest, but because in the ensuing decades after World War II nearly all of the South’s old-growth bottomland forests was logged, except for a few parcels here and there. Congaree remained the largest, but was largely unknown except to a few local hunters and fishermen. Fortunately, much of it was saved in a last-minute effort by conservationists and protected in 1976 by the National Park Service. In 1980, two years after being hired as a wildlife biologist by the South Carolina Department of Natural Resources, I was fortunate in being able to take Peterson up on his challenge of forty years ago. I initiated what is known as a Breeding Bird Census (or BBC, a program of the National Audubon Society) on a representative twenty-acre plot of Congaree’s “original river-swamp habitat.”

My Congaree bird census plot in 1980 shows a very dense canopy with little understory growth.

I conducted the first year’s census in the late spring and early summer of 1980, followed up by three more censuses in 1981, 1982, and 1984. For the four censuses I recorded a cumulative total of twenty-four bird species, fifty percent of which were Neotropical migrants, those birds that nest in North America and overwinter in the tropics. These species also comprised 65% of the total breeding territories.

It was probably no surprise that I found by far the most abundant breeding bird at Congaree to be the diminutive Northern parula warbler, one of the most characteristic birds of southern bottomlands. For the four censuses I found, on average, nearly twenty parula territories per twenty acres, an incredible density of one pair per acre. In fact it appeared at times that the parulas were using one large old-growth hardwood tree as their territory. These large trees are usually draped in Spanish moss, a key ingredient for the warbler, which nests and forages in clumps of moss. And as it turns out, the density of these large hardwoods was about one per acre.

The diminutive Norther parula warbler, by far Congaree’s most abundant breeding bird.

Coming in at a distant second with an average of six territories was the ubiquitous red-eyed vireo, which Peterson considered as the most common bird of Eastern deciduous forests.

Tied for third, with three to four territories per twenty acres, were Northern cardinal, Carolina wren, Acadian flycatcher, and Eastern tufted titmouse. Three species, yellow-billed cuckoo, Carolina chickadee, and yellow-throated warbler, had an average of two to three territories, while eight species averaged between one and two territories per twenty acres, they being pileated woodpecker, hairy woodpecker, downy woodpecker, red-bellied woodpecker, white-breasted nuthatch, great crested flycatcher, white-eyed vireo, and prothonotary warbler.

Seven species, characterized as having large territories or being sparsely distributed, were found to have only partial territories on the plot: wood duck, barred owl, red-shouldered hawk, blue gray gnatcatcher, yellow-throated vireo, and hooded warbler.

The total density of nesting birds, an important figure for comparative purposes, was, as expected, high, ranging from 728 to 932 pairs (or territories) per square kilometer (250 acres) with a four-year average of 800 pairs per 250 acres, or an average of 3.2 nesting bird pairs per acre.

It was significant that my old-growth Congaree bird plot did not have the “edge” conditions – “early-successional” habitats of thickets and scrubby patches of cover – associated with large, widely-spaced trees, as postulated by Peterson. This was borne out by the fact that a characteristic edge (or thicket) species of bottomlands, the white-eyed vireo, had only one to two territories per twenty acres, and the hooded warbler, another bird of dense cover, had only a partial territory.——-to be continued-———-

Essay: Martin’s Folly

I became interested in the history of the Congaree back in the 1970s during the citizen’s campaign to save it. Detractors of a park insisted it was mostly second-growth forest that had grown up after old agriculture fields were abandoned after the Civil War. Park proponents disagreed and used the term “near-virgin forest” to describe it, a term picked up from the 1963 National Park Service Report that documented the uniqueness of the Congaree and recommended its inclusion within the National Park system (“near-virgin” referred to the fact that much of the park’s old-growth bald cypress had been logged in the early 1900s).

This lead me to start poking around in the collections of the South Carolina Department of Archives and History, then located on the corner of Pendleton and Senate Streets. This was well before the digital revolution, and it was a time-consuming and laborious affair to examine the documents from the 1700s and 1800s, bound in thick, heavy volumes.

But it was a nice problem to have in a way because so much of our recorded state history had gone up in flames when Columbia burned in 1865. The only reason we now have access to so many wonderful documents of the past is reportedly due to far-sighted courthouse employees who removed as many documents as they could possibly transport and hid them in a railroad baggage car parked on a siding north of Columbia.

The old plats and royal and state grants for South Carolina are a marvel to behold. Another marvel is how the early surveyors laid out the “metes and bounds” of land grants with such accuracy, using primitive equipment. In fact much of the park’s current boundary lines, and this no doubt holds true for many properties across the state, date back to the very first Colonial surveys done in the 1700s.

The plats and grants that you see at Archives and History are copies, made years ago, of the originals. Many are now on microfilm and available online, but in the 1970s they were still bound in large volumes and covered with a clear protectorate film. In a way looking at these old plats, some of which are more than two-hundred years old, is like communicating with the surveyor across the generations. Surveyors used “witness trees” as boundary markers and the “chain” as the unit of length (a chain being 66 feet; foresters still use chains in their work). A bearing was noted as “W20S, meaning “west 20 degrees south” which translates into a direction of 250 degrees. They would also write down the adjoining landowner(s) names, if known. Sometimes the surveyor would make a note on the conditions of the land surrounding the surveyed property. For the Congaree, it was not uncommon to see the notation, “all cane swamp” or “impassable cane swamp.”

A 635-acre state land grant to Isom Woodward, 1817. The plat is on its side – a clockwise rotation would orient it north-south. 

 

It was one such plat I stumbled across that piqued my curiosity. It was a state grant (although much of South Carolina had been “granted out” before the Revolution, the state still owned a good bit of land after the war – some of these lands were old, abandoned Colonial grants whose original owners never claimed or “improved” them) issued in 1817 for 635 acres to Isom Woodward, an early planter from the “Fork” as lower Richland County was known then. The grant was “situated in Richland District on the branches of the Congaree River.”  Based upon the general location and also being somewhat familiar with the Congaree holdings of adjoining landowners noted on the plat – Green Rives, Abraham Shepherd, and Charles Cotesworth Pinckney, I felt I had reasonable knowledge of the general location of this grant.

What really caught my attention on this plat was a small, dashed, elipitcal outline in the southeastern corner of the plat that the surveyor had labeled as “Martin’s folly.” What was Martin’s folly? Who was Martin? And where was it located? I felt that if I could pinpoint the location of the grant, then maybe I could find a clue as to what the folly was.

It was easier said than done.  What was particularly frustrating about this plat was that it had a lot of clues and details that should have made it fairly easy to locate. It had an unusual shape with a total of thirteen different sides, as opposed to the many rectangular plats in the park with only four sides; it noted three different adjoining landowners whereas some plats had none; and it had several natural features labeled on it: a Beaverdam Gut across the center of the plat; a Cypress Gut on the west side; and a Cypress Pond on the south.

I had had a good bit of success putting together a map of the original land grants of the Congaree. It’s exactly like working on a jigsaw puzzle. The first pieces are the hardest to put in place, but once you get to a critical size, the remainder of the pieces start falling into place.

Well, I spent a lot of time poring over maps and plats, but couldn’t get the piece to fit anywhere. I later found a hint that the grant was on the northeast side of Cedar Creek but still could not find a fit. Over the years I would periodically take a stab at locating the grant, all to no avail, and I finally despaired of ever locating Isom Woodward’s 635-acre land grant and the mystery of Martin’s folly.

Isom Woodward’s 1817 plat overlaid on my Congaree map. The green part of the boundary lines were still extant at the time of park acquisition in 1976. Martin’s folly is shown in the lower right hand corner.

Well, if you live long enough, and have a little luck, sometimes things work out. I think it was around 2008, more than thirty years after I first found the plat, that I had an eureka moment and was able to fit Mr. Woodward’s land grant in what I think is its rightful place. It is indeed on the northeastern side of Cedar Creek and contains several prominent features on my hand-drawn map of the park: Hurricane Pond, Deer Pond, Pine Lake, and Night Heron Flat. The location of Martin’s folly fits in with a neck of high land on the western end of Beaver Dam Slough (a name I came up with well before knowing the location of the Beaverdam Gut noted on the surveyor’s plat).

Being familiar with this little neck of high ground, I didn’t recall any physical feature that would have suggested past human activity. There are (or were before Hurricane Hugo knocked them down) several large old pines nearby on the eastern side of Pine Lake Slough that could indicate a past clearing of some sort. But so far I have not located any on-the-ground evidence that would offer a clue as to the origins of Martin’s folly. Speculation might be the closest we come to solving the riddle.

I’ve always thought the folly was some sort of agricultural enterprise. Was Martin trying to grow rice or indigo here, for example? Old agriculture fields and clearings were usually square or rectangular, however, so why did the surveyor indicate an elliptical outline? Perhaps the dashed lines were following the high ground contours which in this area would be elliptical due to the shape of the surrounding sloughs. And since there are no old dikes, dams, or other such structures to hold back water, was Martin creating a folly by farming in a floodplain without protecting his investment?

Might Martin himself provide a clue? We don’t know much about the family except they were some of the earliest settlers in Richland County. Joseph Martin was granted 200 acres of land in 1757 in the Congaree Swamp on the northwestern side of the Isom Woodward grant. In 1770 Martin obtained another grant for 600 acres in the swamp. He built a house on the north side of Cedar Creek, in the general vicinity of where Dawson’s cabin used to be located, and had a bridge constructed over Cedar Creek to access his swamp holdings, some of which he had under cultivation.

Robert Mills 1825 Atlas of Richland County shows approximate location of Martin’s folly in green and Isom Woodward’s plantation home in red, about where Eastover is now located.

Most of Joseph Martin’s legacy, at least the physical part, has long since disappeared, to the point that it is as if his labors and works never happened. Today when walking along the beautiful bluffs of Cedar Creek, you would never know there was a bridge here more than two centuries ago, a spacious country home nearby, or a narrow wagon road in the swamp leading to his fields, and in one case, folly. Other than a brief will and a few plats, there is nothing in the written record that tells his story. The same applies to many other Congaree landowners: the Adams, Goodwyns, Westons, Woodwards, Hugers, Cooners, Spigners, Seays, Mazycks and others that tried to wrest a living out of the Congaree. Their lost legacies reminds me of the old Christian hymn,

“Time like an ever-rolling stream, bears all its sons away.

They fly forgotten, as a dream dies at the opening day.”

About the only thing left that reminds us that there were people working the Congaree long before us are earthen dikes and cattle mounds, signs of old ferry bridges and abutments, a sentence or two in a will here and there, and tantalizing brief notations and sketches on two-hundred-year old plats.

River Musings

June 11, 2015.  The air is thick with humidity this morning, and there’s fog in the bottoms and low areas. I’m walking along the old Bates Ferry Road (later developed by the park as the Bates Ferry Trail), a one-mile straight stretch of old causeway from US 601 to the Congaree River. It was constructed in 1923, when a new bridge was erected over the Congaree River, and was in use for twenty years, until 1943, when another bridge farther south (where the current one is located) was built over the Congaree.

The old causeway was built to withstand all but the highest flooding, and the borrow pits from whence the dirt to build the causeway was removed are still evident. They are now small ponds that hold water year round and provide good habitat for frogs and toads and other wildlife that need water during dry spells. Lots of thickets and shrubbery, beneficiaries from abundant sunshine, grow along the sides of the causeway and make for good birding. And a variety of butterflies find a home here as well.

The deer flies are out in force this morning and sometimes mosquitoes too. They don’t really relent until I get to the end of the road at Bates Bluff, overlooking the river. After enjoying the view and open horizons, I turn west and cross the old logging bridge at the inlet to Bates Old River (now dangerous and closed to foot traffic since much of the planking is missing and rotten). As I submerge myself back into the dark forest, the deer flies and mosquitoes welcome me like a lost friend.

Norfolk-Southern Railroad Bridge on the Congaree.

I walk down the old logging road that hugs the river as far as the Norfolk Southern Railroad tracks. The river emerges into view again, and I hear a boat coming up river. The boat, a large one with two young men in it, has a big four-stroke outboard motor. These four strokes are amazingly quiet and make half the noise of the old two-stroke engines that you could hear coming down the river a half mile away.

A colony of cliff swallows has built forty or so of their gourd-like mud nests under the new railroad bridge over the river. This would have been a noteworthy sighting a half century ago when cliff swallows first started nesting in South Carolina along the upper Savannah River. Since then they have spread east and south and now cover much the state. Before cliff swallows, this bridge had barn swallows nesting under it. Barn swallows are another relatively new breeding species for the state, beginning with the middle of the last century, and like cliff swallows, they have spread rapidly throughout the state thanks to bridges and highway overpasses. Unlike the more gregarious cliff swallow, barn swallows are often solitary nesters that will use the eaves of porches, outbuildings, docks, and boathouses to hold their mud-constructed nests.

Cliff swallow nests under the US 601 bridge.

I continue walking the old log road westward beyond the railroad through young forest cut over thirty years ago. It is more grown-up in places than the section east of the railroad and has several spurs and dead-end branches that can confuse a first-time hiker. It eventually goes all the way to the original park boundary of 1976, a boundary of old-growth forest clearly demarked like a straight edge from the second-growth forest to the east. This old boundary line runs at a 60º angle all the way from the river to Running Lake Slough, and dates back 250 years to an original 1766 land grant of 800 acres for Susannah Jones.

A summer sky on the Congaree at Bates Bluff.

Four sweat-drenched hours later, I make it back to Bates Bluff at mid-afternoon. A soothing, light breeze from the river provides relief from the heat, and the afternoon clouds are shading the scorching sun. Best of all the bugs are at bay and I lean up against a tree in peace and watch the river go by.

The famous tropical ornithologist and philosopher Alexander Skutch suggested that humans are attracted to rivers because they provide a unique, pleasing combination of permanence and change, two opposing, conflicting traits that we struggle with throughout our lives. Skutch also suggested that one of our primary reasons for being is to enjoy the beauty and loveliness of a natural world that is overflowing with splendor and magnificence.

It certainly seems to me that in a world filled with what is almost a glut of jewel-like hummingbirds (the second-largest bird family in the New World, with more than 300 species!) and other birds of every imaginable color combination (think painted bunting and paradise tanager), as well as thousands of gaudy butterflies, flowers of every color, shape, and description, not to mention lofty forests, rolling plains, picturesque mountain ranges, and lakes and oceans full of incredible life, that there almost has to be the guiding hand of a Divine Providence that provided this overabundance of natural riches simply for us to enjoy. Skutch had that rare ability to find and enjoy beauty in both the aesthetics of nature as well as possessing a scientific mind that delved into the secret lives of birds to find more beauty in their behavior and biology, and to share this knowledge with others.

I have to agree with Skutch that there are few things more peaceful and pleasing than watching a coastal river on its long voyage to the sea. And not far behind me I’m surrounded by a big forest of amazing beauty, mystery, and complexity that offers a lifetime of endless enjoyment.

I finally arise, put my musings aside, and head back to my car parked a mile away next to the U.S. 601 causeway. After nearly eight miles of walking, I see only one “no-shoulders” at what should be the height of snake season, a non-poisonous red-bellied watersnake.

A Fifty-Year Anniversary

June 7, 2015. This morning I hoof it to Sampson’s Island, a mile and a half, and then on to Horseshoe Lake on the Wateree, another mile and a half, for a six-mile round trip. Before parking, I drive to the US 601 boat landing, aka Bates Bridge Landing, and count thirty-eight cars in the parking lot at 7:30. It appears the fish are biting.

The deer flies on the trail to Sampson’s are bad and hungry, and much worse than last year.  Their erratic flight pattern and neon-electric buzzing are enough to drive you nuts, but the worst part is their painful bite, which continues to itch an hour afterwards. One of my favorite sounds is the crunch of crushed fly wing against soft body parts whenever I manage to catch one of the devils and make it pay for tormenting me.

Moth mullein, Verbascum blattaria.

When I arrive at Sampson’s, I find two species of mulleins in bloom, woolly mullein, Verbascum thapus with large, flannel-like leaves, and moth mullein, V. blattaria, with much smaller, and smoother, leaves. The moth mullein gets its name from its “hairy” stamens, reminiscent of a moth’s antenna. Interestingly, this plant has been shown to contain natural pesticides that deter mosquitoes and roaches, with the latter even providing the plant’s specific name (blatta in Latin meaning roach).  By mid-summer some of the mullein stalks will be more than six feet high, and some of the moth mulleins are that tall now. Among the pollinators for both species I see honey bees and a bumble bee. I assume for the former that means a wild nest in a hollow tree somewhere in the swamp. It’s been so long since I’ve seen a wild honeybee nest that I have forgotten what they look like.

Woolly mullein or flannel plant, Verbascum thapus.

A yellow-breasted chat is calling from nearby thickets. It’s interesting to see how the island attracts this species as well as other “un-bottomland-like” birds such as blue grosbeak, Eastern kingbird, Northern mockingbird, chipping sparrow, and even painted bunting.

I see two snakes at Sampson’s – one a slim, three-and-a-half foot black rat, the other a two-foot black racer. They are the only snakes I see today.

The trail to Horseshoe Lake is more open and easier walking than the one to Sampson’s. There are, however, four water crossings, fortunately shallow and narrow, that were formerly crossed with primitive bridging, now all washed out.

I find my old red-maple backrest, the same I used the last time I was here, on the edge of Horseshoe and sit a spell. A very loud bullfrog calling nearby from the back end of the lake lets loose about every five minutes. He dispenses with the preliminary “jug” call and just bellows “rum-rum-rum.” He is joined by a passing fish crow, a red-shouldered hawk, Cope’s gray treefrogs, and the splashing of fish. Occasionally I hear the hum of an outboard motor coming from the Wateree, less than a mile away. The scene before me is full of peace and serenity, helped all the more by a nice breeze blowing off the lake. I sit for nearly an hour and have to force myself to leave.

Horseshoe Lake.

As I gaze out over the brown-water lake, framed by a summer sky full of billowy white clouds on top and luminescent green forest on the sides, I can’t help but reminisce and think of the year 2015 as being an anniversary of sorts, a fifty-year anniversary of outdoor adventures in the COWASEE Basin. It got started in my high school senior year of 1965:  my first trip to Sparkleberry; a solo hike in the Upper Santee Swamp where I was temporarily disoriented for much of the afternoon; drives to the top of Cooks Mountain in a 1947 gray Plymouth; boat trips down the Congaree River; visits to Poinsett State Park and Manchester State Forest; and more. I didn’t realize it at the time, but my life in the outdoors and future career were being shaped by the COWASEE Basin (only back then there was no official COWASEE Basin, just miles and miles of big rivers, expansive river swamps, high hills and bluffs big enough for a seventeen-year old boy to lose himself in). Here it is fifty years later (where did all that time go?) and the seventeen-year-old boy has been replaced by a sixty-seven year-old man who never grew up and still likes to play in the woods and explore this splendid blue-and-green world only thirty minutes from home.  The thrill of finding new discoveries in the natural world, no matter how seemingly commonplace or trivial, continues to hold a grip on me and lures me back again and again to my old haunts. I realize how very lucky I am to have grown up with this unique setting on my back doorsteps at a time when kids were expected to be outdoors all day and “going to Santee” was a way of life for many.