Posts Tagged ‘William Bartram’

Piedmont Plant Species Bartram First Encountered at the Augusta Shoals

July 22, 2018

I’ve read all or parts of Bartram’s Travels hundreds of times, but whenever I re-read it I always find something new that fascinates me.  William Bartram journeyed from Savannah, Georgia to Augusta during 1773, and in his book he describes the flora of the maritime forests, lower coastal plain, and upper coastal plain.  The descriptions are so packed with information I didn’t notice until recently a small paragraph about some piedmont plant species he first encountered alongside the shoals of Augusta.  He refers to this spot as a cataracts.  Several important Indian trails converged here because the shoals afforded a shallow crossing.  Augusta developed as an Indian trading village because of these shoals.  Bartram describes Augusta as a small village that reaches all the way to the “cataracts,” and it was surrounded by “gay lawns and green meadows.”  Augusta is on the edge of the hill country, and species that prefer higher elevations begin to occur here.  Bartram arrived in May when all of these species were in full bloom.  He listed Rhododendron ferruginumPhiladelphus inodorus, Malva, and Pancratium fluitans.   I haven’t visited the shoals in a while, but I don’t recall seeing any of these species next to the shoals.  They’ve been eliminated from the immediate vicinity, though the first 3 are commonly planted as ornamentals in people’s yards.  Bartram wrote Pancratium fluitans inhabited every rocky islet on the shoals.  (The common name of this species is rocky shoals spider lily.  It’s modern scientific name has been changed to Hymenocallis coronaria.)  Unfortunately, today there are just 50 populations of this species left because reservoirs inundate their favored habitat.  The natural beauty of rocky shoals has diminished since Bartam saw them.

Scenes around Augusta, Georgia - Savannah River shoals - Stock Image

Augusta shoals.  The lock was built 100 years after Bartram saw it.

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Rhododendron ferrugineum is a common ornamental plant in Augusta.  It grew wild near the Augusta shoals.

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Scentless mockorange is also commonly planted as an ornamental but wild populations grew near the shoals.

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Common mallow is a non native species that was already widespread in Augusta by 1773.  This is probably the Malva species Bartram mentions.  There is a native species of mallow–Carolina mallow (Modiola caroliniana), however Bartram described the mallow he saw as blue, and this is the wrong color for Carolina mallow.

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Rocky Shoals spider lily.  Only 50 populations of this species still exist.  Most have been wiped out by reservoir creation.  In Bartram’s day they inhabited every rocky islet on the Augusta shoals.

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A 9 Mile Long Dogwood and Magnolia Grove in Alabama (circa 1775)

July 12, 2018

When William Bartram traveled through the south from 1773-1776 he observed many environments that today are either extinct or very rare.  In southern Alabama just east of Mobile he journeyed through a grove of dogwoods and magnolias that was 9 miles long.  This is how he described it.

We now enter a very remarkable grove of Dog wood trees (Cornus florida) which continuing nine or ten miles unalterable, except here and there a towering Magnolia grandifloria; the land on which they stand is an exact level; the surface a shallow, loose, black mould, on a stratum of stiff, yellowish clay; these trees were about twelve feet high, spreading horizontally; their limbs meeting and interlocking with each other, formed one vast, shady, cool grove, so dense and humid as to exclude the sun beams at noon-day.  This admirable grove by the way of eminence has acquired the name of the Dog woods.

The existence of an almost pure stand of dogwoods this large has long puzzled me.  Dogwood is a common understory tree throughout the south but I’m unaware of any natural location where it largely dominates as a canopy species.  Recently, I reread the passage, and the next morning I had a eureka moment–I believe passenger pigeon flocks created this unusually large stand of dominant dogwood trees.  The dogwood grove Bartram observed was likely the site of a massive passenger pigeon roost 50-100 years before he traveled through it.  Flocks of migrating passenger pigeons (Ectopistes migratorius) formerly caused eclipses of the sun lasting for 6 hours, and when they roosted their colonies would so damage the forest it would appear as if a tornado had struck.  The weight of the roosting birds would bust limbs and even crack enormous tree trunks in half.  The dung overfertilized the trees, often killing all of them.  These enormous colonies covered many square miles.  This explains the extent of Bartram’s dogwood grove.

Dogwood trees were already common in the understory of the forest, and the fruit ripens in the fall…exactly when passenger pigeons migrated to the south after nesting in the midwestern states.  It seems likely passenger pigeons fed on the dogwood and magnolia berries in the surrounding forest, and deposited the still viable seeds under their roosts in their dung.  Dogwood trees sprouted in the nutrient rich soil and thrived in the open sunlight created when the overstory trees were destroyed by the passenger pigeons.

Map of Alabama highlighting Conecuh County

Bartram’s dogwood grove was probably located in Conecuh County, Alabama.

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Passenger pigeon migrations eclipsed the sun.

Bartram describes adjacent open plains that also resemble a landscape recovering from a passenger pigeon invasion.  Most of the 70 mile forest surrounding the dogwood grove consisted of oak, hickory, black walnut, elm, sourwood, sweetgum, beech, scarlet maple, buckeye, and black locust with an understory of dogwood, crabapple, and plum.  (Chestnut and pine grew on rocky hills.)  But some pockets of treeless plains within the forest and alongside the dogwood grove were composed of shrubs covered in grape vines.  The shrubs included silver bud, buckeye, bignonia, azalea, and honeysuckle.

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Dogwood berries.  Passenger pigeons ate them.  They taste bittersweet to me.

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Flowering dogwood.  Bartram’s dogwood grove must have been beautiful during early March when the tree blooms.

I’ve always wondered how forests recovered following an invasion of passenger pigeons.  It didn’t occur to me until just recently that Bartram had described just such a site, though he was unaware of how the landscape he described originated.  In summary I shall list the lines of evidence for my hypothesis that Bartram’s dogwood grove was the result of a massive passenger pigeon roost 50-100 years earlier.

  1. The size of the site (9 miles in extent) is the same size as many passenger pigeon roosts described by colonists.
  2. Heavily fertilized soils support monocultures.  The site, fertilized by pigeon dung, supports just 1 dominant species with 1 minor component.
  3. From Bartram’s description all of the dogwood trees appear to be the same age, suggesting they all germinated during the same year.
  4. Passenger pigeons arrived in the region when dogwood trees bear fruit.  This makes my hypothesis plausible because passenger pigeons are the only species that could have planted dogwood seeds on such a large scale.
  5. Adjacent areas also appear to be recovering from a passenger pigeon invasion.  Bartram describes pockets of plains where there are no overstory trees, just shade intolerant shrubs covered in grape vines.
  6. The complete absence of overstory trees indicates a sudden traumatic tree-killing event in the recent past

Pleistocene Pastures and Loggerhead Shrikes (Lanius ludovicianus)

January 18, 2016

The habitat requirements of the loggerhead shrike suggest a long interrelationship with extinct Pleistocene megafauna.  Shrikes prefer grazed grasslands with nearby thickets of short trees for nesting and isolated taller trees for perching.  A cow pasture adjacent to a large yard landscaped with trees and bushes is ideal habitat for a shrike.  Shrikes use the isolated trees as observation posts where they search for prey.  A grazed pasture maintains just the right height of grass so a shrike can find their favorite foods–grasshoppers, mice, lizards, small snakes, and other song birds.  Grass that gets too tall could also conceal a predator such as a fox or cat not averse to making a meal of shrike.  Thickets provide good places for shrikes to hide their nests.  During the Pleistocene mammoths, bison, and horses maintained the range of habitats required by shrikes, the haphazard mix of grazed pasture, isolated tall trees, and thickets.  Despite the unlikelihood that a predatory songbird could become preserved in the fossil record, shrike remains dating to the Pleistocene have been excavated from 2 fossil sites in Florida at Arredondo and Reddick.  Shrikes were probably common in the southeast for millions of years, and they surely witnessed herds of megafauna stirring up prey.  The ancestor of the loggerhead shrike diverged from a Holarctic population of northern shrikes (Lanius excubitor) when Ice Ages began occurring, and glaciers isolated the founding population.

A great grey shrike with an impaled mouse. Photo courtesy of Marek Szczepanek. Source.

A great gray shrike with a mouse it impaled.  They kill their prey by snipping the spine behind the head.  Their claws are too weak to hold on to their prey when feeding and tearing with their bill, so they impale them on thorns or barbed wire.

Following the extinction of the megafauna, shrikes remained common in the southeast.  Fire and Native American agricultural practices maintained favorable shrike habitat.  The characteristics of sand hills with widely spaced pines, scrubby thickets, and sparse ground cover were always a preferred habitat for shrikes.  When William Bartram traveled through the Florida sand hills in 1776 he noted that shrikes (or butcher birds as he called them), along with rufous-sided towhees and Florida scrub jays, were “very numerous.”  He described this landscape as an open pine and palm savannah interspersed with thickets of magnolia, dwarf oaks, devilwood, blueberry, pawpaw, and buckthorn.  In 1939 John May wrote in his classic A Natural History of North American BirdsThe Loggerhead Shrike is an extremely common bird along the roadsides of Florida, where in winter every third or fourth telephone pole seems to serve as an outlook point for either a Mockingbird, a Sparrow Hawk, or a Loggerhead Shrike.”

Unfortunately, loggerhead shrike populations have drastically declined over the past 60 years. I’ve never seen one.  A century ago, before the adoption of the car, horse pastures were abundant across the southeast.  Farmers still raised cattle on all this excess pastureland for decades after cars replaced horse and buggies.  Cotton and corn fields left fallow covered much of the south as well.  Fallow fields rank 2nd to pasture as good shrike habitat.  Much of this favorable shrike habitat has been converted to pine plantations, a type of environment that supports no wildlife.  This ecological disaster also explains declines in the populations of eastern meadowlarks, vesper sparrows, grasshopper sparrows, and bobwhite quail.  In Louisiana and Texas the conversion of cow pastures to rice plantations has caused a decline in shrike populations there.  Invasive fire ants colonize the bare earth left after the rice is harvested, and they compete for the same prey items.

Shrikes are permanent residents in the south.  Shrikes that breed in the Midwest migrate south during the winter.  These migratory populations are suffering an even worse decline.  Territorial shrikes that permanently reside in the south drive away migratory pairs from the remaining suitable habitat.  Migratory shrikes have become extirpated from many areas where they formerly ranged.  One study of shrikes in the North Carolina sand hills region determined that shrikes are disappearing from the periphery of their range, but core populations living in good shrike habitat are stable.  I hope they remain so.  The loggerhead shrike is on my birding wish list.

References:

Lynn, Nadine; and Stanley Temple

“Land Use Changes in the Gulf Coast Region: Links to Decline in Midwestern Shrike Population”

The Passenger Pigeon 1991

McNair, Douglas

“Breeding Distribution and Population Persistence of Loggerhead Shrikes in a Portion of the North Carolina Sandhills”

The Southeastern Naturalist 4 (14) 2015

 

Landscape Paintings by Philip Juras

July 9, 2015

The kind of natural environments I’d like to see are either extinct or currently exist as tiny remnants.  It’s too hot this time of year to get in a car and drive for hours to visit any of these remnant landscapes.  Instead, I like to relax and open up a book entitled The Southern Frontier: Landscapes Inspired by Bartram’s Travels by Philip Juras.  This artist paints landscapes that were once common across the southeast but now exist as rare relics.  In some cases the environments he portrays no longer exist at all, and he has to base his work on descriptions William Bartram made about his travels through the region in 1775/1776.

My favorite landscape is the open oak savannah of the piedmont region.  I’ve written a series for my blog about my imaginary life in a wilderness located in the Georgia piedmont 36,000 years ago.  I envision my wilderness homestead surrounded by open oak savannah as depicted in the below illustrations.

Old growth oak savannah painted by Philip Juras. Imagine centuries old trees with a grassy understory.

Painting of an old growth oak savannah at Sprewell Bluff.  Imagine bison, horses, and mammoths here as they were during the Pleistocene.

Anthony Shoals on the Broad River.  This is what Piedmont rivers originally looked like.  If I lived near these shoals during the Pleistocene, I’d set fish traps up here.

Depiction of the Kiowee Valley, South Carolina as it was in 1775.  Today, this valley is inundated by a reservoir.  This is so beautifulWhat do I like best about it?  No sign of people.

Evidence from pollen records shows that the abundance of oaks and other hardwoods increased while the abundance of pine decreased during warm interstadials and interglacials.   Broad-leafed trees outcompete pines in climates with greater precipitation, milder temperatures, and higher concentrations of carbon dioxide in the atmosphere.  Conversely, pines predominate over broad-leafed trees in colder windier conditions with lower atmospheric concentrations of carbon dioxide, such as occurred during Ice Age stadials.  Natural fires and the grazing, trampling, and foraging of megafauna kept oak woodlands more open during the Pleistocene than modern day woods.  Later, Indians frequently set fire to the woods, maintaining these primeval oak savannahs.  Light grass fires killed saplings, but mature oaks are fire resistant, and burned grass re-sprouts from underground roots.

I like oak savannahs because this type of environment supports a large population of wildlife, and the open nature allows for easy wildlife viewing.  During the Pleistocene a piedmont oak savannah was home for mammoth, bison, horse, peccaries, tapir, deer, elk (probably not until 15,000 BP), llamas, and bear.  Predators attracted to these prey species included saber-tooth, giant lion, jaguar, cougar, bobcat, dire wolf, and coyote.  Squirrels were even more abundant than they are today, and cottontails thrived in thickets left per chance unburned.  Big flocks of turkeys, passenger pigeons, and hundreds of species of songbirds frequented oak savannah.  Just imagine all the wildlife that could be seen from just a glance out the window of a homestead built in the middle of a Pleistocene piedmont oak savannah.

Philip Juras did find a rare remnant of an oak savannah in western Georgia located in Sprewell Bluff State Park.  When I drive through the countryside, I occasionally see an acre or so with old growth oaks and a grassy understory.  I remember seeing an example of this environment on the other side of the road near the base of Ladds Mountain in Bartow County.  This environment is rare now because men have clear cut and cultivated so much of the original landscape.  When the land is eventually left fallow, it doesn’t come back like it used to be.  Men suppress fires and build roads that act as firebreaks.  The native grasses no longer occur in the seed bank, and the soil has been used and eroded.  The trees grow thick on poor soil without light grass fire tinder.  It’s nothing like it used to be.  Pines predominate in the piedmont today, but circa 1704 John Lawson traveled a day through the North Carolina piedmont without seeing a single pine tree.  Instead, the land was covered by oaks and other hardwoods.

Since Philip Juras published his book, he’s continued painting landscapes.  He’s traveled to Little St. Simon’s Island, Martha’s Vineyard, and Colombia.  He’s posted these new paintings on his website http://www.philipjuras.com/  Here’s 1 of my favorite new paintings of his.

This is a freshwater wetland known as Goose  Pond on Little St. Simon’s Island.

William Bartram’s Visit to St. Simons Island in 1774

July 10, 2014

I didn’t go to St. Simons Island this summer as I’d initially planned, but I wasn’t disappointed.  I’m sure the island is not as interesting as it was when William Bartram visited it in the spring of 1774.  Bartram stayed for a few days with James Spalding, then the president of the settlement of Frederica and a merchant involved in the Indian trade.  Although a remnant of an old growth maritime forest has been preserved for the modern day naturalist to enjoy, Bartam had the opportunity to see the island when it was mostly undeveloped.  One day, he left Frederica on horseback to survey the island.  Thick groves of live oaks surrounded the town.

500 year old live oak on John’s Island South Carolina.  There may have been quite a few trees of this age on St. Simons Island when Bartram visited in 1774.

Bartram rode through the virgin live oak woods and found a “beautiful green savannah” about 2 square miles in extent.  Long-horned cattle, horses, sheep, and deer fed in this natural pasture.  On the other side of this savannah, he followed an old road that had fallen into disrepair.  The road went through an open woodland of live oaks and longleaf pines spread far enough apart that grass and shrubs could grow in the understory.  The road ended after 5-6 miles when he reached an impenetrable thicket growing on a sandhill.  The thicket was composed of live oak, myrtle, holly, beautyberry, silverbell, alder buckthorn, hoptrees, bully trees, hornbeam, and bignonia.  Several of these species are evergreen and subtropical.  Greenbriar vines covered the thicket, and there was a salt marsh on the other side of the sandhill.  Bartram referred to it as a “salt plains.”

Bartram did find a freshwater creek between the forest and the salt marsh.  Here, he rested and enjoyed the fragrant beauty of diamond frost, morning glory, lycium (a thorny plant in the nightshade family), scarlet sage, and white lily; all of which were blooming in April.

Diamond Frost Euphorbia Diamond frost in the Euphorbia genus.  It is related to the more famous Christmas poinsetta.  This is one of the flowers Bartram saw growing on St. Simons Island.  Actually, it is the leaves that look like flowers. 

Bartram turned south and found the beach where he saw living and dead starfish, corals, jellyfish, snails, whelks, clams, and squid; all washed upon the sand.  He left the uninhabited beach and headed west, coming across 50-60 beehives lined up in a grove of oaks and palms.  He met a farmer and beekeeper who was resting upon a bearskin rug after a morning spent hunting and fishing.  The man gave Bartram venison and honey-sweetened water spiked with brandy.  They had a picnic amidst the mockingbirds, painted buntings, and hummingbrids.  Jasmine, honeysuckle, and azaleas scented the air. 

William Bartram met a farmer and beekeeper on St. Simons Island who was lounging outside on a beer skin rug while drinking brandy mixed with honey and water.  He must have caught the bear raiding his bee hives.

 ©Zachary_Huang 

An apiary.  Beekeepers and bears do not get along.

On his way back to Frederica, Bartram saw many abandoned plantations.  Even Fort Frederica itself, still manned at the time by a small garrison, was falling apart.  Peach, fig, and pomegranate trees grew through the broken walls.  General Oglethorpe had ordered the construction of the fort 60 years earlier, but funds in 1774 were not available to maintain it.

Fort Frederica on St. Simons Island, Georgia.  General Oglethorpe ordered it built circa 1712 to repel any possible invading colonial force such as the Spanish.  By 1774 it was already in ruins.

I envy the bucolic life of the farmer that Bartram met.  The man had half of St. Simons Island to himself.  For an 18th century existence, this was living in paradise.  Poor city folks in London then were lucky if they had bread.  But this man lived on a beautiful plantation with quite a variety of food available from both land and sea.  On the other hand, he didn’t have air conditioning and television.  And the bikini had yet to be invented.  Today, his plantation has been transmogrified into a landscape of condos built as closely together as possible.  If this farmer could visit the present day for a week, I wonder if he would envy our modern life as I envy his or would he wish to return to his old life.  I wonder…would he trade places with me?

Blueberry and Bumblebee

May 21, 2012

I have 4 cultivated blueberry bushes.  They usually flower in March, produce fruit in June, and offer lovely red foilage in  fall.  This year, winter ended 2 weeks earlier than normal, and Saturday (May 19th) I harvested my first blueberries.  They were plump from a recent drought-breaking rain.  I made my first batch of blueberry pancakes the following morning.  My bushes give me all the berries I need for pancakes, muffins, and desserts for about a month.

My blueberry bushes flower in February and March.  The bees swarm to them every year.  Without these pollinators there would be no fruit.

Note the bees.  The most common species pollinating the flowers are the southeastern blueberry bees and bumblebees.  The former looks similar to the latter but is smaller.

Two bushes.  Two varieties.  One of the four bushes (not pictured) is stunted and doesn’t produce much yet.

Good plump berries by May 18th.

Blueberry flowers attract several kinds of bees well adapted to late winter/early spring weather conditions.  Because these species of bees are covered with hair, they are able to withstand colder temperatures than most other insects and are among the first arthropods to emerge in early spring.  The black coloring also helps increase their body heat.  The southeastern blueberry bees, bumblebees, and honeybees pollinate over 96% of the blueberry crop in southeastern North America.  The southeastern blueberry bee (Hapropodia laboriosa) is by far the most common type pollinating my bushes.  They look like a small bumblebee and are a solitary species.  The female digs a long burrow in sandy soil and broods her nest in it.  Their lifespan matches the length of time blueberry bushes flower–about 3 weeks.  They are completely dependent upon blueberry bushes, unlike bumblebees (Bombus sp.) which pollinate a much greater variety of plants.  Bumblebees live in colonies of from 200-2000 individuals.  They also nest in burrows where the overwintering queen becomes the sole survivor when hard weather hits.  Both of these native bees are not aggressive.  I’ve never been stung by either one.  One would have to roughly handle one of these species or invade a nest to get stung.

Horticulturalists cultivated high bush blueberries, creating hundreds of varieties, but low bush blueberries only grow in the wild.  Nevertheless, there are such extensive stands of low bush blueberries in Maine that they’re gathered wild and can be found in the frozen food section of many supermarkets.  Low bush blueberries grow wild in my neighborhood, including my front yard.  These ripen in late July/early August but are of disappointing quality compared to my cultivated high bush blueberries.  Euell Gibbons claimed wild blueberries work better in muffins than cultivated ones, but the variety that grows in my neck of the woods is hard and bittersweet.  My wife and daughter love cultivated berries but declined to eat the wild ones after trying them.  Eight species of blueberries are native to the piedmont region of the southeast: sparkleberry (Vaccinium arboreum), black high bush blueberry (V. atroccum), high bush blueberry (V. corynborum), Elliott’s blueberry (V. elliotti), southern low blueberry (V. pallidum), deerberry (V. stamineum), slender blueberry (V. tenellum), and early low blueberry (V. vaccillum).

Blueberries generally grow in colonies and prefer sandy acidic soil.  They thrive in sunny open areas with little to no tree canopy.  They can tolerate a few pine trees which don’t shade them.  They’re another fire adapted plant–underground runners help them resprout following ground fires.  When Euell Gibbons went hunting for blueberries, he’d visit the office of a National Forest ranger and ask him to point out on a map where the most recent burns had taken place.  Native Americans set fire to the woods nearly every year to foster habitat for berries, though this was done for several other reasons as well such as improving habitat for game, eliminating insect and snake refuges, and increasing visibility to avoid being ambushed by other Indians.

Undoubtedly, blueberries were a common component of southern Pleistocene landscapes.  Dynamic factors–sudden climate changes, unchecked wild fires, and megafauna foraging–created highly diverse environments including the open spaces blueberries require.  Pleistocene-aged heath pollen in measurable amounts occurred in Nodoroc, a mud volcano near Winder, Georgia (the central part of the state).  The pollen dated to ~30,000 BP, a brief interstadial immediately preceding the Last Glacial Maximum.  The pollen record here suggests an environment dominated by pine, oak, and grass; though hickory, spruce, and fir were common, while maple, beech, chestnut, and birch were present in this diverse landscape. The presence of high amounts of ragweed, an early successional species, is evidence of an environment in constant flux.  Pine pollen and macrofossils at Nodoroc suggest a mixture of southern species (shortleaf) and northern species (jack, red, and white).  In Maine wild blueberries grow in large barrens and are associated with the northern species of pine mentioned above.  One caveat–the heath family also includes common non-blueberry species such as azalea, mountain laurel, and fetterbush, so it’s likely they contributed to the heath pollen.  Scientists can’t differentiate to the species level when examining heath family pollen.

Pleistocene environments in Georgia may have included vast blueberry barrens such as those occurring in Maine today, especially with large flocks of passenger pigeons spreading the seeds that eventually found ideal habitat.  William Bartram rode his horse through miles of what he referred to as “strawberry plains” in north Georgia and North Carolina.  This environment–common just 200 years ago–is now completely extinct. Strawberries require sunny conditions, just like blueberries.  In the extensive wilderness of the Pleistocene perhaps blueberry barrens and strawberry plains covered miles of territory.

Maine blueberry barren.  This photo must have been taken during fall when the leaves turn red.  The owners of this land burn it often to faciliate the growth of wild blueberries–an uncultivated cash crop. Did Pleistocene Georgia have extensive blueberry barrens such as this?  Or did they just grow in small colonies wherever a fire burned a small section of forest?

Sturgeon and Lamprey

May 16, 2012

The destruction of the sturgeon population mirrors the devastation of southeastern primeval forests.  Both of these astonishing natural resources have been utterly obliterated.  In a previous blog entry from about a year ago, I excerpted William Bartram’s 18th century description of a magnificent forest in Georgia consisting of trees with diameters 8-12 feet thick.  I drove through the same area last summer and was hard pressed to find a single tree greater than 1 foot in diameter.  The story of Georgia’s most impressive river fish follows the same plotline.


 

 

 

 

 

Man Alive!  Look at the size of this Atlantic sturgeon.  There used to be so many of these fish in our southeastern rivers that they posed a navigational hazard.  Now, they are almost extinct.

The sturgeon run in southeastern rivers began in mid-May.  For the first month of the run most of the spawning sturgeon averaged 3-4 feet in length, but beginning in mid-June and lasting until mid-September sturgeon averaging 6-9 feet in length were common.  Captain John Smith, founder of the Jamestown colony, caught 62 sturgeon in 1 haul of a net, though that take was extraordinary, even for that time.  More often, netting would yield 7 or 8 large sturgeon in a few hours.  The schools of sturgeon “clogged” the river and made for a dangerous navigational hazard that could upturn boats.  Occasionally, the giant fish even jumped into a boat.  John Lawson, an early naturalist who traveled and settled in North and South Carolina circa 1704, wrote that he saw hundreds of sturgeon every day. (He also mentioned pulling 300 chain pickerel from 1 fish trap in a single day.)  Now, sturgeon are almost extinct.  There is a tiny breeding population in Georgia’s rivers but none of the rare sturgeon found in mid-Atlantic rivers breed there.  About 1850  men began overfishing sturgeon which formerly were considered trash fish.  This decimated the population, but dams and muddy erosion from agriculture blocked and smothered much of their former spawning grounds–perhaps the final death blow.  Sturgeon need shallow water with gravel bottoms for spawning, but instead, if the spawning fish themselves are not blocked by dams, the gravel bottoms have become covered in mud, making them unsuitable.  The sturgeon eggs need to adhere to gravel.

Three species of sturgeon, all endangered, live in Georgia.  The Atlantic sturgeon (Acipenser oxyrhincus) reaches the most spectacular size, obtaining a maximum length of 9 feet and a weight exceeding 800 pounds.  The adults live in the lower stretches of the river and near offshore ocean water, but they used to spawn as far as 300 miles up the river.  The juveniles stay in the river until they’re about 7 or 8 years old before they migrate to the ocean.  They return when they reach breeding age which isn’t until they’re between 10-30 years old, explaining why it’s so difficult to bring back sustainable population levels.  They feed on the bottom by scooping out depressions and lying in ambush nearby.  Smaller fish and invertebrates carried by the current fall into these saucer-shaped traps next to where the hungry sturgeon awaits.  The short-nosed sturgeon (Acipenser brevirostrum) is similar in habit to the Atlantic sturgeon, but it is smaller in size reaching 4-5 feet in length and just 50 lbs in weight.  A landlocked population of lake sturgeon (Acipenser fluvescens) lived in the Coosa River  until 1965.  In 2003 biologists reintroduced them to the Etowah River.  The Coosa River lake sturgeon must have been a relic population that some how made their way from the Mississippi River system, perhaps from a chain of wetlands that existed during the Pleistocene in northern Alabama.  Floods between river basins must have facilitated the spread of this species.

Flickr

Sturgeon piccatta, broccoli, and stuffed squash blossoms.  I’ve never eaten fresh sturgeon.  I think I’ve had smoked but it’s been so long I can’t remember for sure.  I’ve had caviar…tastes like fish guts.

It’s hard to believe the early settlers considered sturgeon a trash fish and fed the flesh and caviar to the hogs and dogs.  Sturgeon flesh when dressed correctly is reportedly supposed to be mild and durable and an acceptable substituted for boneless chicken breasts or veal in recipes.  Caviar, of course, is considered a delicacy but in my opinion tastes like fish guts.  Mixed with cream cheese, it’s palatable.  In my fantasy Pleistocene world, I’d definitely be harvesting and eating the sturgeon.

Sea lampreys parasitize fish, latching on and ingesting blood.  Sea lampreys no longer occur in the Savannah River, but they used to.  They must have been dependent on the large sturgeon population.

Sea lampreys (Petromyzon marinus) are no longer recorded from the Savannah River, but there is a historical record of 1 from the upper part of this river where Clark Hill Reservoir now inundates.  John Lawson mentions sea lampreys as a fish the Indians refused to eat (though the French consider them a delicacy).  This anectodal evidence suggests sea lampreys used to be fairly common in southeastern rivers.  They’ve likely disappeared from the Savannah River because they depended upon sturgeon for sustenance and now that the sturgeon are all but gone, so are the lampreys.  It’s no coincidence that sea lamprey spawn in the same habitat as sturgeon–shallow water with gravel bottoms.  The larva move downstream after hatching, then burrow into sandy or muddy bottoms and become filter feeders, living on detritus and algae until they grow into their parasitic phase.  When they reach this stage they actively attack fish as depicted in the figure above.  I suspect sturgeon were their primary prey/host in southeastern rivers.  Striped bass and swordfish have been recorded as preying on sea lampreys, but probably any large predatory fish will eat them.

At least 3 other species of lampreys inhabit Georgia’s rivers–the southern brook lamprey (Ichthyomyzon gagei), the American brook lamprey (Lampetra appendic), and the least brook lamprey (Lampetra aegypidtra).  The former occurs in the Chattahoochee River, and the latter 2 live in north Georgia rivers.  None of these have a parasitic phase and they live as filter feeders burrowed in mud for most of their lives, except when they spawn.  They all have rasping mouths, however.  This is evidence they evolved from parasitic species.

Sturgeon are an ancient family of fish.  Fossils of sturgeon dating to the Cretaceous prove they swam when dinosaurs roamed the earth.  Lampreys long ago evolved to exploit this once abundant food source.  It’s a shame both of these remarkable fish have nearly vanished in the last 150 years in the wake of man’s environmental destruction after they’d successfully survived natural ecological changes for over 100 million years.

Pleistocene Vultures of Southeastern North America

July 13, 2011

It seems fitting to follow last week’s blog entry about saber-tooths with one about vultures, a whole class of birds that benefited from the big carnivore’s work.  The extinction of the megafauna led to the extinction of several vulture and condor-like species.  Other species of scavenging birds became less widespread and more local in distribution.

Teratorn

Teratorn–Teratornis merriami

This huge condor-like bird stood 2.5 feet tall but had a wingspan of 12 feet–the length of 2 average-sized men spread from head to foot.  Fossils of this species have been excavated in Florida, California, and several western states, so it likely ranged throughout most of the southeast.  An even larger species, Aiolornis incredibilis, had a wing span of 17 feet, but this may have been an early Pleistocene species, not present in the late Pleistocene.  The teratorn’s bill was much larger than other vultures, suggesting it often took live prey such as rabbits and bird nestlings which it swallowed whole.

African scavenging birds occupy different niches described as rippers, grabbers, and scrappers.   Rippers rip open thick-skinned, large, carcasses and eat hide and the tougher parts of the animal.  Grabbers eat the soft meat; scrappers eat the bits of meat that get scattered around the carcass.  Scientists believe the same holds true for scavenging birds in Pleistocene North America.  Teratorns were the rippers, capable of opening dead thick-skinned mammoths or ground sloths, helping make the meat available for other scavengers.

California CondorGymnogyps californianus

Photo from google images of a California condor.  Man, are they ugly.

I say this bird should be known as the North American condor because Pleistocene age bones of this bird have been found as far east as New York (the Hiscock site) and Florida.  Obviously, it lived throughout the southeast.  Scientists know from an analysis of its fossil bone chemistry that California condors survived the extinction of the megafauna because a local population of the birds learned to scavenge whale carcasses off the California coast.  Ranchers attempting to kill coyotes with ill-conceived poison control programs, instead nearly extirminated the beneficial condors.  Now, they’re back from the brink, feeding mostly on the abundant dead livestock on western ranges.

American griffin vulture?  No common name–Neophrontops americanus

An extinct American vulture related to old world vultures.  No representatives from the old world vulture family still occur in North America.

The accipitrids are old world vultures today found in Africa and Eurasia.  They’re more closely related to hawks than to extant new world vultures which are related to storks.  The physical similarity between old and new world vultures is a case of convergent evolution when unrelated species develop similar characteristics to adapt to similar conditions.  Both old and new world vultures have featherless necks to prevent the build-up of toxic bacteria.  Both are capable of digesting well-rotted food without getting sick, and they are adapted to tearing open carcasses.

American old world vulture.  No common name–Neogyps errans

This is another old world type vulture that became extinct with the megafauna.

King Vulture–Sarcaramphus papa

William Bartram described this vulture in north Florida during the 18th century.  For over a century ornithologists doubted the veracity of Bartram’s account, thinking he either had the bird confused with a mythical creature or a caracara, because no specimens of this still living species were known to occur north of Central America.  Then in 1932, Frances Harper reviewed Bartram’s field notes and discovered that Bartram actually had obtained a specimen.  The description in the field notes matched the king vulture even better than his account in his book, Travels, which was written years later apparently from imperfect memory.  Mr. Harper theorized the king vulture occurred in Florida until the great freeze of 1835.  Bartram also reported royal palms in north Florida which were extirpated from all but the southernmost region of the state after that freeze.  King vultures probably colonized and recolonized the south during warm interglacials.

Bartram noted an interesting habit of this species in Florida.  King vultures followed the frequent fires in the longleaf pine savannahs and ate the “roasted” reptiles that failed to escape the flames.

Black Vulture–Coragyps atratus

Photo from google images of a black vulture–still common.

It’s no coincidence that drivers often spy these still extant birds soaring over highways.  They’ve adapted well to the roadkilled supermarkets of our modern highways which offer a buffet of dead deer and dogs.  Two fossil specimens of black vulture nestlings found at Kingston Saltpeter Cave, Bartow County prove this bird lived here during the Pleistocene as well.

Turkey vulture–Cathartes aura

Photo of google images of a turkey vulture.  They’re easy to distinguish from black vultures even if one can’t see the red head because they’re flying high in the sky.  Note the tail is much narrower on a turkey vulture than a black vulture.

Turkey vultures are still common but don’t congregate in large flocks like black vultures do.  Their niche differs too–they subsist on smaller carrion such as dead possums, flattened road-killed snakes and squirrels, etc.

Eagles also benefited from the deaths of Pleistocene megafauna.  Grinell’s crested eagle and hawk eagles, now extinct, probably relied on carrion for an important part of their diet.  Golden eagles and bald eagles were probably more comman then, thanks to the abundance of meat on the range.

Caracaras, ravens, and magpies were also more widespread during the Pleistocene because of the greater supply of meat.

References:

Harper, Frances

“Vultura sacra of William Bartram”

The Auk October 1932

Hertz, Fritz

“Diversity in Body Size and Feeding Morphology within Past and Present Vulture Assemblages”

Ecology 75 (4) June 1994

Fire Suppression = A Decline in Biodiversity (part 1)

June 27, 2011

The title of this week’s blog entry seems to be a recurring theme in my essays about Georgia’s natural history.  Productive natural landscapes such as longleaf pine savannah, oak forests, and canebrakes are disappearing or nearly extinct due to fire suppression; and the same goes for “strawberry plains,” chinkapins, and many species of animals which will be the focus of part 2 of this series.

Prescribed burn at the Savannah River Site in South Carolina.  After decades of a Smokey the Bear fire suppression policy, the U.S. forest service finally realized controlled fires were beneficial to the ecology.

Fire has always been an important component of Georgia’s ecology.  Before people colonized the region, wildfires occurred irregularly but were unchecked and often burned on a large scale.  Fires were more common during interstadials because of an increase in thunderstorm frequency.  Oaks increased in abundance in correlation with wetter climate cycles, thanks to lightning-sparked fires that opened up the forest canopy for these fire tolerant/shade intolerant trees.  Mammoths, mastodons, and ground sloths littered the forest floor with tree branches and killed trees by eating the cambium under the bark.  During droughts, this litter dried into tinder ready to explode when struck by lightning.  I hypothesize that windstorms and tornadoes were common in the south during much of the Pleistocene.  Frigid katabatic winds blowing off the Laurentide Glacier met warm tropical fronts from the Gulf of Mexico and the Atlantic Ocean in the atmosphere directly over the southeast.  Because cold air sinks, when cold fronts hit warm fronts, great downdrafts of cold air microbursts snapped trees in half and leveled forests.  All this deadwood added fuel to fires as well.  Pollen records show grass was abundant prior to human colonization of the southeast–evidence that natural fires and other disturbances must have been common, though lower CO2 levels in the atmosphere, drier climate phases, and megafauna foraging and trampling contributed to the expansion of grasslands as well.

Following the extinction of the megafauna, forests grew densely for a few thousand years but Indians changed this situation.  Indians began burning the woods to improve habitat for game, and to eliminate shrubby growth that might provide refuge for ticks, stinging insects, large predators, and hostile human warriors interested in carrying off attractive women.  Burning the woods created favorable habitat for bison, deer, and turkey–staples of the Indian diet.  Most fires would not kill healthy mature trees but would eliminate saplings and unwanted brush.  (See the appendix below for tree species fire tolerance.)  Fire created open woodlands which were pleasing to the eye.  Open woodlands allowed more sunlight to reach ground level and in combination with fire sparked the growth of nutritious grasses, flowering herbs, and berry bushes.  Much of the southern uplands consisted of open pine savannah in the coastal plain, and pyrophitic oak forests in the piedmont.  Canebrakes that stretched for miles grew along the piedmont riversides and creeks.  C.C. Frost reconstructed a map of the natural environments on the Savannah River Site based on descriptions of original land acquisition surveys.  This probably is a good representation of a typical section of southeastern coastal plain.

Presettlement vegetation map of the Savannah River Site  reconstructed by C.C. Frost and published in the below referenced book.  Longleaf pine savannahs made up 80% of the landscape.  Bottomland hardwoods, pyrophitic oak forests, longleaf pine-turkey oak sandhills, canebrakes, and Carolina bay wetlands were also common.  The area also includes a bluff forest with northern species of plants but there was less than 300 acres of this.

SRS lies within the coastal plain so longleaf pine savannah dominated the region until 1820.  Note all the yellow in the above map which represents pine savannah.  The pink represents canebrakes, now a completely extinct ecotone on the site, having been replaced by bottomland forests.  Pyrophitic oak forest (the brown) were well represented as well.  Early European settlers copied the burning practices of the Indians, but about 1820 an improved version of the cotton gin was invented, making cotton farming highly profitable.  This is when the burning stopped, and much of the natural forest was converted to farmland.

Vegetation map (also from the below referenced book) of the SRS in 1952 after the government purchased the land.  The federal government replanted much of the land in slash and loblolly pine because longleaf pine was hard to obtain, the trees grew more slowly, and seedling quality was poor.

By 1952 the remaining forests were of poor quality.  Fire suppression ruined the upland forests, and logging the best trees degraded the bottomland forests.  Most of the forests had been replaced by horizon-to-horizon cotton farming.  Note on the map that the cleared land closely corresponds to the former range of the pine savannah.  Note also how canebrakes completely vanished, replaced by bottomland forest.  Canebrakes required specific flooding and firing regimes to persist.  Bamboo cane colonized areas near rivers where the trees were either destroyed by prolonged floods or by the nesting of enormous flocks of passenger pigeons which would kill the trees via overfertilization as their dung accumulated beneath their nests.  Bamboo cane continued to dominate only if the canebrakes were burned about once every 10 years.  Fires more frequent than that created grassland; fires of lesser frequency than that led to the growth of bottomland hardwood forests which shaded out the cane.  Canebrakes provided lots of fodder for bison, denning sites for large carnivores, and habitat for many small species from swamp rabbits to rare types of butterflies.  The burning of canebrakes took place in winter, and it sounded like combat because the hollow stems exploded upon ignition.

Canebrakes were formerly very common in the piedmont.  In 1773William Bartram travelled through central Georgia on his way to the Gulf Coast.  His party traversed on high, dry, gravely ridges but were always in sight of extensive cane meadows which flourished at the bottom of the hills alongside creeks.  On the ridges themselves pyrophitic oaks forests grew.  He found plenty of fire adapted plants growing between the oak trees including goldenrod, asters, rosinweeds, cone flowers, milkweed, false aloe, and spurges.  Bartram noted that Indians set fires annually, and normally clear rivers turned black with ash.

All southern pines are fire tolerant and adapted to survive in environments with frequent fires.  Most oak species also are fire tolerant, though to a lesser degree than pines.  However, longleaf pine is adapted to fires as frequent as 1-4 years, a higher fire frequency than most oaks and pines can survive in the long term.  The long pine needles form a sheath that protects the main stem of a sprout.  Mature loblolly pines, shortleaf pines, and many oak species survive light to medium fires, but their saplings can not.  Longleaf pine saplings can survive fire, explaining why longleaf pine savannahs became the dominant ecotone on the coastal plain.  Fires were less frequent  in the piedmont and mountains because rugged terrain and myriad creeks formed natural firebreaks.

Reference:

Kilgo, John; and John Blake

Ecology and Management of a Forested Landscape: Fifty years on the Savannah River Site

Island Press 2006

Appendix I: Ranking fire tolerance among species common in the southeast

Longleaf Pine

Loblolly and Shortleaf Pine

Black oak

White oak

Red oak

Appendix II: Best fire regimes

Grasslands–annually

Longleaf pine Savannah–1-4 years

Canebrake–10 years

Oak forest–10-30 years (sources differ wildly on this)

 

Megafauna game trails, then Indian Trails, now State Highways

May 25, 2011

Last week, my quest to find the site of the 18th century Great Buffalo Lick took me on a journey along Highway 22.  Few people who travel Georgia’s state highways realize that many of these roads through the piedmont region closely follow the routes of old Indian trails.  And Indians were simply following ancient megafauna game trails.

Historical map of known Indian trails.  I think Highway 22 originally was a branch of the Pickens Trail.  According to the treaty signed with the Creek Indians in 1773, an Indian trail that closely mirrors modern day Highway 22 formed the western boundary of what was to become Wilkes County.

Recall that last week, I chased a turkey hen with my car up the gravel road that led to Kettle Creek Battlefield.  The turkey chose the path of least resistance and seemed reluctant to leave the road for the cover of the brush because it takes more energy to run though thick vegetation.  Animals don’t like to waste energy.  They need to retain as much body fat as they can so they can survive hard times when there is less food or when they can’t forage due to injury.  Therefore, animals tend to travel along paths already trodden down by other animals or created by man.

While driving on a state highway, it’s exciting to contemplate that I’m probably following a path of considerable antiquity.  The routes could be tens of thousands of years old.  Originally, a herd of mammoths or mastodons formed the trail, beating down the grass and brush, stomping flat the saplings, ripping off overhanging tree branches.  Herds of bison, horses, llamas, deer, and peccary used the trail, keeping the path an open avenue.

Photo of a game trail in Africa formed by elephants and followed by other animals.  Even though this part of Africa is open grasslands, animals prefer to travel along the same routes to avoid resistance from plants and terrain.  Photo from the book The Early Settlement of North America: The Clovis era by Gary Haynes.

The paleoIndians followed these game trails too which were more prevalent in the piedmont region for two reasons: Unlike in the coastal plain, rivers in the piedmont were rapid with lots of rocky shoals, precluding the ease of travel by boat.  And the piedmont was more forested, necessating a preference for clearly marked trails both for ease of travel and to keep from getting lost.  Indian trails in the piedmont followed high ridges and avoided frequent crossings of deep creeks or wide rivers.  When they did lead to river crossings, they converged at shallow rocky areas that were easy to ford.  A number of Indian trails converged at what’s now Augusta because there are rocky shoals here that make fording the river easy.  I’ve crossed them myself many years ago.  If it wasn’t for these shoals, Augusta would not exist.  Fort Moore was the predecessor to Augusta.  General Oglethorpe chose this site for a trading fort because many Indian trails converged here.  Because open pine savannahs and wide navigable rivers prevailed in the coastal plain, Indian trails were less common or necessary there.  State roads built after World War II no longer needed to follow these old trails because heavy machinery made it possible to flatten hills, grade uneven land, and construct large bridges.

Reference:

http://southernhistory.net/modules.php?op=modload&name=News&file=article&sid=10256&mode=thread&order=0&thold=0

Warning: I’m getting on my soap box about the complete destruction of Bartram’s magnificent forest.  I am bitter.

I wrote about an impressive old growth forest described by William Bartram in my April 11th blog entry.  On my expedition to find the Great Buffalo Lick, I also searched for remnants of this forest and found absolutely none. ( I assumed the state highway followed the old Indian trail.)   As I suspected, the entire forest, many square miles of “gigantic” black oaks, sycamore, sweetgum, and hickory must have been cleared by cotton farmers between 1790-1860.   Today, the area from Little River to Philomath consists almost entirely of dense stands of loblolly pine and sweetgum–a monotonous nearly dead ecosystem.  I saw only a few black oaks–none of them “gigantic.”  Instead of  a “thinly planted by nature” oak parkland, it’s practically a monocultured thickly planted tree farm.  I saw not a single tree more than a foot in diameter, whereas William Bartram traveled through 7 miles of trees that were 8-11 feet in diameter.  I estimated, based on the appearance of this loblolly pine and sweetgum second growth, that the area was one big cottonfield until about the 1930’s, perhaps reverting to field following the boll weevil infestation that broke the back of agriculture here.

I can’t believe the greedy bastards who first cleared this land for growing cotton couldn’t protect even a small park of this original forest.  We will never see how beautiful the original environment was in this area.  It was destroyed before photography was invented, and no 18th century artist chose to paint it.  Instead, these stupid, illiterate bullies used slave labor to cut every single tree down, remove every stump, burn every bit of lumber refuse, and they continued to plant cotton seed in the bare red earth until the once rich soil and landscape transmogrified into a worn out old hag of its former self.  The natural beauty of the original environment has gone with the wind.

This is one more disgraceful legacy of southern white people.  In addition to crimes against humanity (slavery and an insurrection that led to the deaths of millions) I charge them with crimes against the environment with their destruction of Bartram’s magnificent forest.  Neither did I see remnants of the Indian mounds Bartam mentions, so go ahead and consider white southerners guilty of crimes against archaeology as well. 

I condemn white southerners for their disgraceful history, and for their current political stances which are still overwhelmingly backward, racist, ignorant, and short-sighted.