Posts Tagged ‘Nodoroc’

The Mysterious Nodoroc Site in Winder, Georgia

January 9, 2013

The geological origin of a mud volcano located in Winder, Georgia is a mystery waiting to be solved.  As far as I know, geologists haven’t ever studied this unexplained watery bog that last erupted circa 1800.  It’s probably similar to mud volcanoes found in Africa and southeast Asia.  About 10 years ago, a mud volcano in Cameroon exploded and killed a whole village by carbon dioxide asphyxiation. The carbon dioxide displaced the oxygen in the atmosphere.  An atmosphere of just 10% carbon dioxide causes people to become comatose; an atmosphere of 30 % CO2 causes people to drop dead immediately.

Winder, Georgia is in Barrow County which is between Athens and Atlanta.  My grandparents used to live there.

Nodoroc is a Creek Indian word meaning gateway to hell.  It’s an odd natural boggy pond that used to release a constant bluish smoke while bubbling.  The Creek Indians built an altar of heavy stones on the edge of the volcano where they executed criminals and then threw the corpses in the bog.  It was their way of sending deserving souls to hell.  They believed the volcano was protected by the wog–a devil dog with red eyes and the head of a bear.  Despite the cultural importance of the site, the Creek Indians sold the pond and the land around it to the English for 14 pounds of beads.  Some early colonist made off with the altar and now it’s lost to archaeologists.

I couldn’t find a photo of Nodoroc on google images that I could confirm was the actual site, but the below link is an aerial photograph.  The brown muddy expanse is labeled and obvious to see.  The link below that is of video of a mud volcano in Yellowstone National Park.  Unlike Nodoroc, it is still active and it probably has a different kind of origin.  The Yellowstone mud volcano is caused by heating and cooling subterranean rock on a fault line, while the Nodoroc mud volcano resulted from decaying organic matter.

http://www.wikimapia.org/#lat=33.973821&lon=-83.6727574&z=19&l=0&m=b

http://www.youtube.com/watch?v=iJ8qfpMkDs0

The first European explorers to visit Nodoroc say that it burned and dissolved everything they threw in it.  Even rainwater evaporated when striking the bog.  They reported that the area attracted lots of animals, but I think the abundance of wildlife resulted from Indians avoiding the place which they only used for executions.

Circa 1800 John Gosset built a cabin nearby and cleared a field around Nodoroc.  One day, Gosset and his wife witnessed the last eruption of the mud volcano.  His wife noticed an unusual amount of fog over the bog that morning.  She called her husband who was busy ploughing to come see it.  A loud explosion was followed by a shower of hot mud particles.  After the eruption the volcano settled several feet and cooled.  Decaying matter likely caused a fermentation reaction, releasing carbon dioxide and methane that had been trapped under the mud.

In the days of free range livestock Nodoroc was known as a cattle mire because cows constantly were  getting stuck in the quicksand-like mud.  Farmers eventually erected a fence to prevent any more losses.  Nodoroc was formerly about 5 acres in extent but circa 1900 John Harris drained part of it and grew several successful crops of corn.  While ploughing, he often came across bones and horns.  They were mostly the bones of recent cattle, but I suspect they may have been mixed in with Pleistocene fossils–a point I will discuss later.

Gary Bolton, a layman, visited the site in 1987 out of curiousity.  He noted that tulip tree saplings had colonized part of the pond, but many fell over, as if the shaky marsh ground couldn’t support deep roots.  Most of Nodoroc was covered with “thousands” of crayfish chimneys.  He mentioned sticking a shovel in the pond and finding that the level of muck was deeper than the shovel itself.

Acidic peat bogs are rare in the piedmont region of southeastern North America.  Peat bogs often contain and preserve pollen, plant macrofossils, animal fossils, and human artifacts.  So far, Nodoroc has only attacted 2 paleobotanists.  Dr. Stephen Jackson and Dr. Donald Whitehead investigated the site in 1981 and published their findings 10 years later.  They took 2 deep piston cores of sediment that they analyzed.  They did find 2 statigraphically datable segments in the core: 1 dated from 26,000 BP-22,00 BP, and the other from 3600 BP to the present.  This study was done before radiocarbon dates were recalibrated.  These dates roughly translate to between 30,000 calender years BP-26,000 calender years BP, and from 4,000 calender years to the present.  The lack of continuous stratigraphy is explained by long periods of time when water level was low and deposition didn’t occur.  The oldest segment dates to the weak interstadial immediately prior to the cold phase that led to the Last Glacial Maximum.

The site itself was probably an open marshy environment during the interstadial.  Plant macrofossils and pollen indicate an abundance of sphagnum peat moss, arrowhead (Sagitteria sp.), sedges, and carnivorous pitcher plants growing directly on the site.  Shrubs such as alder, myrtle, and mountain laurel and/or blueberry (Ericereae genus) grew on the marsh edge.  Pines and oaks dominated the forest surrounding the site.  With the exception of white pine (Pinus strobus) scientists can’t distinguish between species of pine by looking at pollen grains. After looking at the pine pollen and pine needle fossils under a microscope Drs. Jackson and Whitehead were only able to eliminate 3 species–longleaf, slash, and table mountain, none of which would have been expected to be here anyway.  However, the size of the pollen grains suggests both northern and southern species of pines were present.  Northern species of pine tend to have smaller pollen grains, while southern species of pine tend to have larger grains.  Both large and small grains were present.  My educated guess is that jack pine (Pinus banksiana) and shortleaf pine (Pinus echinata) were the dominant pinus species, while white pine was also present.  Macrofossils of jack pine, a species that now no longer occurs farther south than Michigan, have been found in Missouri and north Georgia sites dating to the mid-Wisconsinian interstadial.  Apparently, it was a more widespread species then than it is today.  Shortleaf pine, a southern species, occurs as far north as southern Ohio, and its short needles can endure snowy and icy conditions without much damage.  There’s no way of determining which species of oaks predominated here–all oak pollen looks too similar.

Other important trees growing in this interstadial forest were Critchfield’s spruce (my species assumption), fir, and hickory.  Chestnut, beech, sugar maple, and birch were present but at low levels.  (After the Ice Age chestnut became much more abundant in the region until its unfortunate extirpation 100 years ago.)  Hazelnut was a common bush growing in the understory.  During the Wisconsinian Ice Age hazelnut ranged throughout the south but is practically absent here today.  Noticeably absent or rare then were sweetgum, tupelo, and red maple all of which are common today in this area.

Fir trees thrive in regions with snowy winters.  As I mentioned in last week’s blog entry, the piedmont region of southeastern North America during the Ice Age was an abrupt transition zone between subtropical Gulf Coast Corridor grasslands and boreal forests of the Southern Appalachians.  Humid tropical fronts often hit cold air causing lots of snowfall.  Critchfield’s spruce, firs, and short-needled pines were and are well adapted to the snowy conditions that may have once blanketed the south.  It would have been interesting to see this environment where warm climate fauna frequently wandered to mix with creatures from the cold north.

I’m surprised no Pleistocene fossils habe been discovered or noticed from Nodoroc.  If cows often perished in the mire, I’m sure some of the Pleistocene megafauna did as well.  Perhaps the Indian legend of the wog is based on skeletel material of extinct beasts they discovered.  If I owned the pond I’d have it dragged for fossils and artifacts.

Artist’s rendition of the wog, a creature of Creek Indian legend that supposedly guarded Nodoroc.  Was the legend based on Pleistocene-aged fossils Indians found in the bog?  Cows used to get stuck in the mire and perish.  Pleistocene megafauna must have also.  This site should be prospected for Pleistocene vertebrate fossils which are probably mixed with modern livestock bones.

References:

Bartow County Historical Society

The History of Nodoroc and Tales of the Wog

Jackson, Stephen; and Donald Whitehead

“Pollen and Macrofossils from Wisconsinian Interstadial Sediments in Northeastern Georgia”

Quaternary Research 39 1993

Wilson, Gustavius

The early history of Jackson County, Georgia

W.E. White 1914

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The Pleistocene Floral and Faunal Invasion of Southeastern North America

January 4, 2013

The Pleistocene fossil record of southeastern North America includes many species of plants and animals that had their origins in the neotropics of South America and the western grasslands of North America.  Disjunct populations of some of these species still exist in the southeast, especially in Florida.  Dr. David Webb may have been the first scientist to propose the former existence of a broad corridor on the coastal plain along the Gulf of Mexico that connected the southeast with these other regions.  This corridor has intermittently existed since the late Miocene, and most recently during the Last Glacial Maximum when sea level fell drastically as much of earth’s water became locked in glacial ice.  Dry land along the Gulf of Mexico emerged above sea level, greatly expanding this corridor as the map below shows.

Note how far dry land extended into the present day Gulf of Mexico during the LGM (~28,000 BP-~15,000 BP).  The state of Florida was twice its modern size.  A mixture of subtropical savannah, prairie, and scrub habitat probably covered most of this land.

The coastal prairies of Louisiana and Texas are a small remnant of this once more vast environment.

The coastal regions that emerged above sea level and most of south Florida supported a kind of lost world consisting of subtropical to warm temperate savannahs.  Paradoxically, climate in this corridor was warmer during the Last Glacial Maximum than today’s climate is there, and it was probably frost free.  During interglacials (such as the present one) and interstadials of the past, the gulf stream carries warm tropical water north where it cools, sinks, and returns south.  But during stadials, icebergs and meltwater break free from glaciers, and they cool and shut the gulf stream down, and the warm tropical water stays off the coast of the south Atlantic and in the Gulf of Mexico.  This created a thermal enclave in south Florida and along the Gulf of Mexico, but the palynological fossil record is incomplete, and it’s unknown exactly how far inland this thermal enclave extended.  It probably didn’t extend far because boreal taxa such as jack pine, red pine, white pine, spruce, and paper birch occurred as far south as the ridge and valley region of north Georgia.  There must have been an abrupt transition zone in the piedmont between the warm savannahs of the coastal plain and the cooler pine and spruce forests of the Appalachian Mountains.  Only 1 Pleistocene floral fossil site is known from the Piedmont region of Georgia–Nodoroc, a mud volcano that captured pollen and some framentary plant macrofossils.  But this site dates to just before the stadial that led to the LGM.  The pollen and macrofossils from this site indicate a mixed forest of northern and southern pines and oaks interspersed with meadows.

Ironically, during interstadials the Gulf Stream became re-established and warmed most of North America, but south Florida and the Gulf Corridor became cooler, though not subfreezing in south Florida.  Sea level rose and the corridor shrunk during interstadials.

Frequent tropical storms, lightning-ignited fires, and megafauna foraging gave the landscape its open appearance.  Longleaf pine savannahs and grassy prairies likely dominated the Gulf Coast Corridor.  Small areas avoiding the trio of landscape engineers became oak scrub.  Prairie acacia (Acacia angustissima) and hairy grama grass are among the notable plants that invaded the south through the corridor.  Prairie acacia is a close relative of the acacia tree that occurs so commonly on African savannahs.  Like African acacias, it was probably abundant, thanks to megafauna foraging.  Acacia trees produce edible pods eaten by elephants and formerly, mammoths and mastodons, and they spread the seed in their dung.  But the bark is poisonous and megafauna avoid eating it.  This explains the prevalence of acacia trees on landscapes where megafauna still live.  Unlike African acacias, the prairie acacia is merely a bush.  The modern range of prairie acacia includes Texas and Mexico with a disjunct population in Florida.

A thicket of praire acacia.  It was probably common on the Gulf Coast Corridor.

Hairy grama grass is among many species of western prairie grasses that have disjunct populations in the east.  A small disjunct population of hairy grama grass occurs on an island off the west coast of Florida.

Hairy grama grass.  A western species with a disjunct population on an island off the west coast of Florida.

Neotropical species of animals that invaded the south through the Gulf Coast Corridor included opposum, giant ground sloths, armadilloes, glyptodonts, tapirs, peccaries, capybaras, gompotheres, jaguars, ocelots, margays, vampire bats, Brazilian free-tailed bats, Mexican long-nosed bats, ghost-faced bats, terror birds, crested caracaras, great-tailed grackles, giant tortoises, indigo snakes, and whip snakes.  Western species of animals that invaded the south through the Gulf Coast Corridor included bison, lions, cheetahs, 13-lined ground squirrels, jack rabbits, hog-nosed skunks, badgers, pocket gophers, burrowing owls, ravens, magpies, prairie chickens, white-tailed kites, diamondback rattlesnakes, hog-nosed snakes, harvester ants, digger bees, some iceunomid wasps, and sand roaches.

The crested caracara is a tropical bird that colonized the Gulf Coast Corridor during the LGM.  In Florida caracaras and burrowing owls almost exclusively nest in heavily grazed pasture, suggesting their former close affinity with Pleistocene megaherbivores.  They prefer shortgrass environments over ungrazed tall grass areas.

Today, a few relic habitats remain from this once continous corridor.  Coastal prairies in Lousiana and Texas are perhaps the best example.  Florida dry prairies are another.  The formerly widespread longleaf pine savannahs on the coastal plain were a close analogue to the Gulf Coast Corridor but not an exact match because frosts do occur there.

Louisiana coastal prairie.  This is probably what much of the Gulf Coast Corridor looked like.

Just to the north of the warm subtropical grasslands, an environment consisting of an extinct temperate species of spruce (Critchfield’s) grew with modern hardwood species such as oak, maple, elm, hickory, and walnut.  The farther north and west from the Gulf Coast Corridor, the colder the climate was.  The spruce and deciduous forest likely predominated in this abrupt transition zone where the climate suddenly changed from tropical to temperate.  Tropical fronts often hit cold air and probably caused snowy winters here.  Summers were cool but winters moderate in the transition zone.  Birdwatching would have been interesting in the transitional zone between the warm Gulf Coast Corridor and the boreal forests of the mountains.  Harsh winters would have chased boreal avifauna farther south, and during summer tropical stragglers would have expanded their range north.

If I Could Live In the Pleistocene (Part Three)–The Turkey Trap

December 10, 2010

(For parts 1 and 2 of this irregular series, see the September archives.)

I imagine living in my snug adobe brick house on December 10th, 41,000 BP.  Though this is during an interstadial, a warm wet climatic phase occurring within the time span of the Wisconsinian Ice Age, the weather currently is dry and cold; the temperatures are dropping to 10 degrees Fahrenheit at night, and all three of my wood stoves are turning wood I chopped into fire and smoke and indoor warmth.  I’m hungry for meat, but I’m a little tired of eating venison and peccary, and in this cold weather I don’t feel like getting wet checking my fish traps on the river.  This year, no bison came close enough to my home for me to kill and butcher, so I have no beef.  Instead, I’ll settle for turkey.

Turkeys were abundant during the Pleistocene, large flocks of perhaps 100 or more roam the woods around my house in the Pleistocene piedmont region.  I awoke to the sounds of their gobbling this morning.  Fossils of turkeys in Georgia have been recovered from Kingston Saltpeter Cave and Ladds Mountain, both in Bartow County, which is halfway between Atlanta and Tennessee, so that’s the real evidence they were common here.  There were two species of turkey, at least in Florida, during the Pleistocene, including the common one found today Maleagris gallipavo, and Maleagris leopaldo or anza, western species that colonized the southeast during glacial stages when a corridor of grassy scrub habitat extended along the gulf coast on land now submerged by the Gulf of Mexico.  Warm tropical climate allowed even more species of turkey (at least 7) to live across North America during the Pliocene.  Turkeys evolved in America from a peacock-like ancestor, Rhegiminornis calbates, during the Miocene.  Fossils of this ancient species were discovered in Florida.

Habitat in the Pleistocene piedmont of what’s now Georgia was almost ideal for turkey.  Modern day wildlife game managers work with farmers and lumber companies to maintain turkey managment areas that include fields half-covered with small trees and shrubs.  Turkeys forage for weed seeds and insects in the fields but can retreat to brush to escape predators such as great-horned owls and bobcats.  In addition they like fields that border forests of mature trees that provide roosting sites and mast.  Pollen evidence from the Nodoroc site in Winder, Georgia suggests the piedmont region of what’s now Georgia (about 29,000 years BP) was 75% forest and 25% meadow–an environment in which turkeys would thrive.  Fire, drought, rapid climate fluctuations; and megafauna browsing, grazing, and trampling maintained open areas within the forest where turkey populations probably were high most of the time. 

In late fall and early winter male turkeys are in good condition, living in bachelor flocks and fattening on acorns.  So now is the time of year to catch and eat them (Of course, I’m referring to my imaginary Pleistocene existence.  Hunting season for present day turkeys  is in the spring), but I don’t want to aimlessly wander the wilds where in my distraction of the hunt, I might get ambushed by Smilodon fatalis or some other big cat.  Instead, I’m going to use a colonial American method that was formerly quite common and effective–the turkey trap.  There’s a modern misconception that our colonial ancestors were all gun-toting hunters.  Although it’s true that many did have firearms and did actively hunt, most did not.  In fact, gun ownership per capita was lower during colonial times than it is today.  Hardworking farmers didn’t have time nor the strength for hunting after putting in 12 hour days plowing the fields, taking care of the livestock, building fences, chopping firewood, doing household chores (like making soap from scratch and smoking hams), and making carpentry repairs on their cabins.  To catch wild game for the cooking pot, they set traps and snares.  Turkey traps were devastating for the birds.

Sketch of a colonial turkey trap.  The ditch dug under a wooden pen was baited with corn.  The turkeys followed the bait into the pen but couldn’t figure their way out in much the same way a crab trap works.  I have no idea who drew this sketch but I found it at http://woodsrunnersdiary.blogspot.com/

Colonial turkey traps consisted of a small wooden shed and a ditch baited with corn.  The ditch extended under the shed.  The turkey went into the ditch, ate and followed the corn into the shed or pen.  They’d hop up into the shed to eat more corn…but didn’t have the sense to escape by following the ditch back outside.  The colonists could then simply open a hatch to the pen, grab the bird, and execute it.  These traps could yield many birds at once.  According to J. J. Audubon, colonists occasionally forgot to check on the traps, perhaps they were too busy working or they got tired of eating turkey, and dozens of turkeys would starve to death and rot, making the whole area stink.  Audubon also reported that predators occasionally were attracted to these turkey pens–he once discovered a black wolf feeding on trapped turkeys.  In my Pleistocene world I block the entrance to my turkey trap when not in use because I abhor waste.

Reportedly, wild turkeys have better flavor than domestic turkeys, and they have more dark meat but less white.  The chances of catching one much larger than supermarket turkeys are also much higher.  Modern domestic turkeys are bred to have white skin and extra large breasts, and they’re most often harvested when they reach 15 pounds.  Domestic turkey breasts are so large, the meat must be embalmed with a salt water solution to keep the birds from drying out during roasting.  They’re bred to have white skin because it is more visually appealing than the black skin of the wild birds.  They are sold as 15 pound birds because that’s about the right size for roasting.  Wild turkeys that I catch in my Pleistocene turkey trap can weigh as much as 30 pounds.  I don’t bother roasting them.  Instead, I stew the thighs and drumsticks in a crockpot.  I shred the cooked meat and smother it in a gravy made from the liquid they cooked in.  I thicken it with a roux of butter and flour and season it with salt, sage, and thyme.  The shredded meat and liquid makes an excellent base for a Brunswick stew with vegetables grown in my Pleistocene garden (crushed tomatoes, corn, lima beans, potatoes, onions) and seasoned with salt, and red and black pepper.  The dark meat makes good ground meat and mixed with half venison yields an delicious meatloaf.  I smoke the breasts and wings.  The smoked breast meat is good for sandwiches; the smoked wings season a pot of red beans.  The breast meat can also be cut into filets and breaded and fried or cooked in a pan sauce with wine, mushrooms, and garlic.  Turkey carcasses make soup stocks superior to that made from chicken, so I have a ready supply of broth for the kitchen as well.

If I could live during the Pleistocene (part two)

September 17, 2010

As I noted in last week’s blog entry, I don’t like roughing it.  If I’m going to live 41,000 years BP, I want to live in a nice sturdy house that would keep me safe from hungry bears, big cats, wolves, and rough weather.  I’d build a big adobe brick house with a wall around ten acres behind it where I could have a garden, fruit orchard, grain fields, and room to raise livestock such as milk cows, chickens, ducks and geese.

If I could live 41,000 years BP, I’d reside in an adobe house.  Adobe bricks are simple to make, only requiring mud, grass or sand, and sun.

My adobe house would have double thick walls, and raised windows with bars in front of them to prevent beasts from breaking into my abode and making a meal of me.  (For more about adobe houses see this link–     http://desertphile.org/adobe/adobe.htm)

In front I would have a raised platform or balcony for wildlife viewing, and on occasion to provide a place for hunting when I need meat.  Most of my home would be one story, but I’d have a tower room, built not unlike a lighthouse, which would afford a panoramic view of the surrounding landscape.  To improve the view, I’d clear a circle of land around my dwelling which would also serve as a firebreak.  My water supply would come from a well.  A dry toilet, or clivis multrum, would take care of my waste.  

Woodstoves would keep me warm in the winter, but I don’t think I’d need an air conditioner because this is the Ice Age, and summers are comfortable.  Solar units, and a generator, using wood alcohol that I would manufacture,  provide my electricity.  Of course, I’d have all necessary machines–bulldozers, bushhogs, trucks, boats, etc.  All engines would be modified to run on wood alcohol.

My Pleistocene adobe house is located in what’s now Elbert County on a hill one mile north of the Broad River and two miles west of the Savannah River.  In my opinion the Georgia piedmont (at least in the still rural areas) is the prettiest region of the state.  I even like it better than the north Georgia mountains.  I’d locate my home relatively close to a river for the easy source of protein–fish, turtles, freshwater mussels, and crayfish.  It would be necessary for me to maintain a dirt road between my house and the river.

I can take an educated guess as to what kinds of plants and animals I would encounter around my house.  There are only two Pleistocene-aged fossil sites in central Georgia (Nodoroc and Little Kettle Creek), though there are many more to the north and south.

Nodoroc is a bog that formerly was a mud volcano, last erupting in 1810 with a massive release of carbon dioxide.  These mysterious types of eruptions have also occurred in African lakes within the last few decades.  Nodoroc is a Creek Indian word meaning gateway to hell because the Indians used to execute criminals and toss them in this bog.

Scientists found plant macrofossils and pollen here, dating to 28,000 years BP, during a brief weak interstadial just before the Last Glacial Maximum.  The forest around the site consisted of an interesting mix of northern and southern species of pine as well as oak.  Northern species of pine such as white, red, and jack tend to have smaller grains of pollen, while southern species, such as shortleaf, tend to have larger grains.  Both size variations were found here, though it’s not possible to identify exact species, based on pollen.  But some plant macrofossils, though not in good enough condition for certain identification, compared favorably to red and/or jack pine; others compared favorably to shortleaf pine.  Because both northern and  southern species of pine occurred here then, the climate must have had mild summers and mild winters

Current range map of the red pine (Pinus resinosa).  Most of where it currently ranges was under glacial ice during the Ice Age, so it must have occurred south of this area then.  I propose that northern species of pine such as red and jack (Pinus banksiana) spread throughout the upper south following cold arid climate cycles when river beds dried out and wind blew the sand into large eolian sand dunes.  Scrub oak and grass initially colonized these dunes, but when precipitation increased as an interstadial began, lightning-induced fires burned the scrub oaks forests and grasslands, allowing fire-adapted pines to colonize these areas.  Eventually, as the climate continued to get warmer and wetter, hardwood trees outcompeted and replaced these shade-intolerant species.  Insterstadials never lasted long enough for hardwood forests to completely outcompete northern pines–a return to cold arid conditions would’ve probably killed many deciduous trees, allowing pine to regain territory.  But the current interglacial we live in now has lasted long enough for broad-leafed forests to shade out red and jack pines in the upper south, except for isolated relic populations of the former in small areas of West Virginia.

Hickory, spruce, and fir pollen were also common; chestnut, beech, and maple were present in low numbers.  The understory consisted of alder, blueberry and/or rhodadendron, and hazlenut.  Enough ragweed, grass, and sedge pollen was present to suggest the presence of large meadows or small prairies, making up to 25% of the landscape.

Little Kettle Creek is the only Pleistocene-age animal fossil site in the entire piedmont region of southeastern North America.  Teeth and bones of mammoth, mastodon, bison, white tail deer, (cf) southern bog lemmings, (cf) red backed voles, and catfish were recovered here.  The two rodents no longer range farther south than Kentucky, again indicating cooler summers for central Georgia during the Ice Age.  Mammoth and bison grazed the meadows;  mastodon and deer foraged the forest edge and streamside woodlands.  Growth rings on the catfish bones are evidence of colder winters than those of today because modern day catfish in warm southern states don’t have dormant growth cycles like fish found in northern states.

Fossil sites to the north and south of the piedmont have more species and most of them probably also lived in what’s now central Georgia as well.  Around my Pleistocene house I would also expect to see Jefferson’s ground sloth, elk, horses, tapirs, llamas, peccaries, dire wolves, jaguars, saber-tooths, bears of at least once species, giant beavers, and many smaller species of extant mammals that no longer occur in state but still live to the north and west.  Examples of interesting small species I’d expect to see are the hognosed skunk, red squirrels, and the extinct noble chipmunk.  I’d also expect to see a much greater variety of birds than I’d see today in an unspoiled wilderness devoid of human habitat destruction and pesticide use.  I’d be on the lookout for northern ravens, magpies, prairie chickens, upland sandpipers, terratorns, California Condors, and extinct species of vultures and eagles.  Birds that are rare or extinct today but were common then include bald eagles, ivory-billed woodpeckers, Carolina parakeets, passenger pigeons, swans, and cranes. 

That abundance of wildlife is the reason I really wish I could move into my Pleistocene home.

One final thought for today: This Ice Age ecosystem I describe was the norm.  Today’s interglacial ecosystem is an aberration because Ice Ages last ten times longer than interglacials.

Pleistocene Passenger Pigeon Populations

August 27, 2010

(Please forgive the excessive alliteration in the title.)

It’s hard to imagine the massive number of passenger pigeons (Ectopistes migratorius) that used to live in North America as recently as the mid to late 19th century.  For a description of their numbers, I’ve dug up an account J.J. Audubon gave in his Ornithological Biography.  Before I reprint this passage I want to comment on his writing style.  I enjoy his prose, but he does have a bad habit of writing in the passive voice, a style Stephen King in his book, On Writing, referred to as farting in an elevator.  Also, English was his second language because he was born in France.  Nevertheless, I think this makes for a fascinating description of a nature scene that no longer exists.

The multitudes of wild pigeons in our woods are astonishing.  Indeed, after having viewed them so often, and under so many circumstances, I even now feel inclined to pause, and assure myself that what I am going to relate is fact.  Yet I have seen it all, and that too in the company of persons, who, like myself, were struck with amazement.

In the autumn of 1813, I left my house at Henderson, on the banks of the Ohio, on my way to Louisville.  In passing over the barrens a few miles beyond Hardensburgh, I observed the pigeons flying from north-east to south-west, in greater numbers than I thought I had ever seen them before, and feeling an inclination to count the flocks that might pass within the reach of my eye in one hour, I dismounted, seated myself on an eminence, and began to mark with my pencil, making a dot for every flock that passed.  In a short time finding the task which I had undertaken impractical, as the birds poured in countless multitudes, I rose, and counting the dots put down, found that 163 had been made in 21 minutes.  I traveled on, and still met more the farther I proceeded.  The air was literally filled with pigeons; the light of the noon-day was obscured as by an eclipse; the dung fell in spots, not unlike melting flakes of snow; and the continuing buzz of wings had a tendency to lull my senses to repose…

“It may not, perhaps, be out of place to attempt an estimate of the number of pigeons contained in one of those mighty flocks, and of the quantity of food consumed by its members.  The inquiry will tend to shew the astonishing bounty of the great Author of Nature in providing for the wants of his creatures.  Let us take a column of one mile in breadth, which is far below average size, and suppose it passing over us without interruption for three hours, at the rate mentioned above as one mile in a minute.  This will give us a parallelogram of 180 miles by 1,  covering 180 square miles.  Allowing two pigeons to the square yard, we have one billion, one hundred and fifteen million, one-hundred and thirty-six thousand pigeons in one flock.  As every pigeon daily consumed fully half a pint of food, the quantity necessary for supplying this vast multitude must be eight million seven hundred twelve thousand bushels per day.”

***********************************************************

Some archaeologists believe the massive population of passenger pigeons that colonists in North America reported from 1700-1870 was a temporary phenomenon.  Thomas Neuman has written at least two journal articles suggesting passenger pigeon populations exploded following the decimation of Indians after their first contact with European diseases such as smallpox, influenza, and measles.  Before this, Dr. Neuman believes this species was not particularly common.  Supposedly, when Indian populations were reduced, there was more forest mast available for birds because humans weren’t gathering the nuts and acorns they fed upon.  In his book 1491 Charles Mann discusses this theory and notes that archaeologists find few passenger pigeon bones at sites of large Indian settlements.

I disagree with this theory because it makes little sense for several reasons which I shall enumerate.

1. Passenger pigeons could not survive as a species unless they existed in extremely large populations.  The survival strategy of this species was to reproduce rapidly and roost and nest in enormous colonies so that they overwhelmed predation.  Predators ate many individuals, but there was a limit to how much their stomachs could hold.  If, as these archaeologists suggest, the passenger pigeon was just an occasional bird, the species would’ve become extinct long before the white man arrived on the continent because their defense mechanisms revolved around living in large colonies.

2. Even if human populations were at the high end of what archaeologists believe, they would’ve made little impact on the amount of forest mast available.  Pre-Columbian forests were extensive, and there was always plenty of forest mast for both humans and huge pigeon colonies.

3. Archaeologists don’t find many passenger pigeon bones in sites of large Indian settlements because Indians probably went to their roosting grounds and feasted on them there and simply didn’t bring the bones back to their villages.

4. Jacques Cartier, an early explorer, reported large pigeon colonies on Prince Edward Island in 1534…before Indian populations were reduced by disease.

5. Pigeon fossils are abundant in an early Holocene fossil site in Western Canada (Charlie Lake, British Columbia).  They are also a common fossil in late Pleistocene avifaunas including Bell Cave, Alabama, Cheek Bend Cave, Tennessee, and Ladds and Kingston Saltpeter Cave in Georgia.

At Ladds fossils of only 4 bird species were discovered.  Passenger pigeons were 1 of the 4.  This may be coincidence, but it’s believed that passenger pigeon biomass made up 25% of all bird populations in North America during the early part of the 19th century.  Many more species of birds were found in the deposit at Kingston Saltpeter Cave.  I compared the minimum number of individual passenger pigeon fossils from KSC to the total bird remains of all other species found there.  Ruffed grouse were the most common species, making up 30% of bird remains, but passenger pigeons made up 6%, despite being a highly migratory bird.  Assuming they spent 6 months of the year around KSC, that means at times, they may have made up to 12% of the bird population in the area.  If they stayed in the area around the cave for only 2 months of the year, they quite possibly made up 36% of the bird population at certain times of the year there.

I must mention, however, that estimating ancient bird populations based on the number of bird fossils found in cave deposits is a rather dubious method.  Nevertheless, habitat for passenger pigeons in southeastern North America during the Pleistocene must have been ideal for this species.

During colonial times this bird nested throughout the midwest, but spent September-February in southeastern states.  For much of the duration of the Wisconsin Ice Age, most of the area where they later nested was under glacial ice, so it’s likely their nesting areas shifted south.  They probably were year round residents everywhere south of the Laurentide ice sheet, except during nesting season when they nested in southern river bottomlands where beech and oak trees remained plentiful, even during cold arid climatic phases.

Today, beech trees are a rare relic in much of the southeast, but during certain climatic phases of the Wisconsin Ice Age, they were even a dominant tree on some lands, according to records of fossil pollen in Alabama, and South Carolina.  From 14,000-11,000 years BP beech was a common tree, while pine, which dominated southern forests during the LGM, temporarily declined drastically.  Beech is well adapted to pigeon and squirrel foraging because this tree spreads through sucker roots, and if animals eat the tree nuts, this species can still propagate.  Beech tree pollen is also present in the Nodoroc fossil site in central Georgia near Winder and at the Gray’s Reef site off Sapelo Island, which was above sea level 30,000 years ago.  The latter site yielded evidence of a forest consisting of a strange mixture of cool temperate and warm weather species of plants.  The south’s Ice Age ecosystem was a mixture of woodlands and grasslands, and it provided excellent habitat for passenger pigeons.  I think the expansion of southern beech tree forests, as the Ice Age waned, is evidence the population of pigeons may have spiked about 14,000 years BP, creating the nucleus that later colonized the midwest after the glacier melted and broadleaf trees re-established themselves there.

References.

Driver, J.C.; and K.A. Hobson

“A 10,500 year sequence of bird remains from the southern boreal forest region of western Canada”

Arctic 45 (2) 1992

Ellsworth, Joshua; and Brenda McComb

“Potential effects of Passenger Pigeon flocks on the structure and composition of pre-settlement forests of eastern North America”

Conservation Biology 17 (6) pp. 1548-1558 2003

Mann, Charles

1491

Knopf 2005

www.paleodb.org