Archive for April, 2014

The Nonconnah Creek Fossil Site in Memphis, Tennessee

April 28, 2014

Only 1 vertebrate species was excavated from Nonconnah Creek, a tributary of the Mississippi River that flows through Memphis, Tennessee.  In 1977 some kids found a skull complete with tusks and teeth of a male mastodon, later estimated to be between 15-18 years old at the time of its death.  Archaeologists and geologists soon descended upon the site and conducted a wonderful study that is very exciting for the paleoecology geek in me.  They found plant macrofossils and pollen, snail shells, and even insect parts in the sediment mixed with the mastodon specimen–a jackpot of information that can help scientists determined what the environment was like in this region during the late Wisconsinian Ice Age.

Nonconnah Creek is on the right side of the Mall of Memphis parking lot.  The mastodon fossils were uncovered after construction workers dug drainage ditches. 

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Photo of tusk and teeth from the Nonconnah Creek Mastodon.  This photo is from the below reference.

The mastodon found here died about 20,000 calender years ago during the Last Glacial Maximum when the Laurentide Ice Sheet reached its maximum extent as far south as central Ohio.  The environment around Nonconnah Creek was much different during the LGM from that of today.  A closed canopy forest consisting of spruce and oak dominated the landscape.  The most common species of spruce in this forest was an extinct species known as Critchfield’s spruce (Picea critchfeldii).  (See:https://markgelbart.wordpress.com/2011/09/03/the-extinction-of-critchfields-spruce-picea-critchfieldii/)  This species had longer cones than the extant white spruce which it resembled.  This spruce and oak forest likely extended as far south as Louisiana and as far east as western Georgia.  Summers were much cooler, but winters were just slightly cooler than those of today.  Average temperatures were not as cold as scientists initially thought because they were using the presence of existing species of spruce trees as a proxy for temperature range, not realizing the spruce fossils they were finding were from an extinct species that was probably at home in temperate climates.  Foggy conditions often prevailed in the area then.  Glacial meltwater descending down the Mississippi River struck warm fronts originating from the Gulf of Mexico creating a cool moist environment that favored spruce trees.  The Mississippi River had a braided pattern with many exposed sandbars.  Frequent cold winds, blowing from the northern Ice Sheets,  blew sand dunes from the river into the spruce and oak forests, occasionally burying the trees.  This explains how these plant fossils were preserved.  (See:https://markgelbart.wordpress.com/2011/08/28/the-fossil-rich-region-of-tunica-hills-louisiana/).  Other species of trees occurring in this Ice Age spruce/oak forest included willow, chestnut, black walnut, hickory, paper birch, elm, cherry, sycamore, sugar maple, and red maple.  Mistletoe, a spruce tree parasite, was found here as well. Though modern hardwoods were present, they were far outnumbered by spruce.

The environment during the Farmdalian Interstadial that preceded the Last Glacial Maximum differed markedly from the spruce/oak forest discussed above.  Between 32,000 BP-28,000 BP, open pine and oak woodland with prairie openings prevailed here.  The Farmdalian was a weak interstadial that gradually gave way to cooler temperatures with lower evapotranspiration rates and lower CO2 levels in the atmosphere–conditions that evidentally favored spruce.  Fewer thunderstorms and lightning strikes reduced the incidence of wild fire, probably also explaining why closed canopy spruce/oak became dominant over open pine and oak woodland. 

 

Valvata tricarinata–A freshwater snail  It’s a common freshwater snail of lakes presently located north of where the Laurentide Glacier extended during the Last Glacial Maximum.  It’s uncommon south of that region though a disjunt relic population lives in the Savannah River, Georgia.  Interestingly, this was the most common species of snail found in the Nonconnah Creek fossil site–evidence its range was displaced farther south during the Pleistocene

Most of the Pleistocene-aged snail shells found at this site were from species commonly found in the region today, and they represent denizens of a variety of aquatic habitats from stagnant pools to fast moving streams.  Dam-building beavers and natural forest debris slowed down some parts of the creek while in other parts it was unimpeded.  Scientists identified 2 species of snails that no longer occur in the region. Today, Fossaria reflexa is restricted to the New England region, but during the Ice Age this species evidentally was displaced at least as far south as Tennessee.  Valvata tricarinata is a common snail species today in the region that was covered by glaciers during the Ice Age.  This species was also displaced south of its current range.  Curiously, a few disjunct populations of Valvata are found as far south as the Savannah River, but it is not common in the southern parts of its range.  However, it was the most common species of snail found at Nonconnah Creek during the Ice Age.  Snails are creatures often used to illustrate slowness, but these 2 species were able to keep pace with rapid climate change when they recolonized newly available habitat after the Ice Age.

 

 Dicaelus sculptilis - Dicaelus sculptilis

Dicaelus sculptilis, a ground beetle today found north and west of Nonconnah Creek.  It was the only recognizable insect found as fossil remains, dating to the Ice Age.

Most of the grasshopper and beetle remains associated with the mastodon had been dashed to unrecognizable smithereens.  However, scientists were able to identify 1 species–Dicaelus sculptilis, a ground beetle that currently ranges to the north and west of this site.

Reference:

Brister, Ronals; John Armon and David Dye

“American Mastodon Remains and Late Glacial Conditions at Nonconnah Creek, Memphis, Tennessee”

Memphis State University Anthropological Research Center Occasional Papers 10 1981

 

 

 

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Flying Filet Mignon

April 23, 2014

Cranes are North America’s tallest birds.  There are 2 species of cranes that live on this continent–the sandhill (Grus canadensis) and the rare whooping (Grus americana).  The former grows to as much as 4 feet tall, while the latter can grow a few inches taller than its cousin.

Four-Sandhill-Cranes

Top photo is of sandhill cranes; the bottom is of whooping cranes.

Cranes inhabit open environments such as savannahs, marshes, and agricultural fields where they can use their keen eyesight to detect and flee from potential threats.  They are omnivorous, feeding upon grains, underground tubers, small vertebrates, shellfish, and insects.  Oddly enough, they don’t usually eat fish.  They were notorious among pre-Civil War planters for digging up leftover sweet potatoes missed by slave harvesters.  Today, they still take advantage of inefficient machine harvesting and feed on leftover grain in farmer’s fields.

Some species of crane has lived in North America for at least 10 million years.  A species resembling the extant crowned crane of Africa lived in Nebraska during the Miocene.  Its fossils were among those found at the Ashfall Fossil Beds located in that state.  Sandhill crane fossils dating to the early Pleistocene (~2 million BP) have been excavated from the Leisey Shell Pits in Florida.  Both species of crane are well represented in Florida’s fossil record, and a crane specimen was also excavated from Bell Cave, Alabama.

Both sandhill and whooping cranes were abundant in southeastern North America when Europeans began colonizing the region.  John Lawson referred to them as “hoopers” because of the loud sound the whooping cranes make.  J.J. Audubon wrote their calls could be heard from 3 miles away, thanks to their 5 foot long vocal cords.  Audubon recounts an humorous experience he had when hunting a crane.  He was traveling on a boat down the Mississippi River when he spotted a flock of cranes.  He jumped off the boat and took a shooting position but was so anxious to show off his marksmanship that he made a bad shot and merely winged one while the rest flew away and escaped.  The injured bird couldn’t fly and Audubon began chasing it across the savannah.  He trapped it against a fallen long, but the bird spread out its wings and charged him.  Audubon, afraid of the long sharp bill, turned around and fled toward the boat with big bird in hot pursuit, a spectacle that caused his companions to laugh heartily.  One of his companions saved him by using a paddle to bludgeon the agressive bird to death.

Like all of North America’s most spectacular species, cranes were nearly overhunted into oblivion.  Hunters especially desire cranes because they are a delicacy known as “ribeye of the sky.”  I’ve never had the chance to eat crane, but I have tried ostrich and it tastes exactly like beef tenderloin, therefore I think “flying filet mignon” might be a more accurate nickname.  Reportedly, crane meat is lean but ribeye is a very fatty cut of steak. (If it was up to me,  all ribeye steaks would be ground into hamburger–that’s all this cut is good for.)

The good taste of crane meat almost doomed whooping cranes to extinction.  Whooping cranes completely disappeared from eastern North America–the last sighting of this species in Georgia was on St. Simon’s Island in 1885.  The entire population fell to just 15 birds, but with federal protection the western population has increased to 270 birds.  They summer in Wood Buffalo National Park Canada, and they winter in the Aransas National Wildlife Refuge, Texas.  An attempt to establish a second western population failed because the birds were hatched using sandhill cranes as surrogate parents.  The whooping cranes in this experimental population imprinted on sandhill cranes and wouldn’t mate with their own kind.  An attempt to re-establish an eastern population has been more successful.  There are now 104 whooping cranes that summer in Necedes National Wildlife Refuge, Wisconsin and winter in St. Marks NWR, Florida (which I visited last summer.  See: https://markgelbart.wordpress.com/2013/06/06/wakulla-springs-shellpoint-beach-and-the-st-marks-wildlife-refuge/).  Scientists used hand puppets resembling whooping cranes to rear the founders of this population, and they got them to imprint on fixed winged aircraft that led them on a migration to their winter habitat.  This population is currently unsustainable because a species of biting black fly is preventing the birds from having successful nesting.  Researchers hope to move the cranes to a different area of Wisconsin where this species of fly doesn’t live.

Whooping cranes following fixed wing aircraft they imprinted on.

Sandhill cranes populations are in much better shape than those of their cousins, though they have been much reduced compared to their former abundance.  A year round population of sandhill cranes lives in south Georgia and Florida.  This population is augmented by winter migrants that spend summers in northern states and Canada.  Some nothern migrants also winter in Louisiana and Texas.  Last year, Tennessee opened a hunting season on sandhill cranes.  When I first heard about this, I thought it was a mistake, but I changed my mind.  An estimated population of 87,000 sandhill cranes migrate through Tennessee but the state only issued a total of 1200 permits, and to be eligible, hunters have to take a course proving they can tell the difference between a sandhill crane and the rare protected whooping crane.  I doubt such a conservative limit will put much of a dent in the population.  Moreover, sandhill cranes are difficult to approach and not every hunter is guaranteed to bag one.

Andrew Zimmern and the hunters who bagged a sandhill crane for an episode of Bizarre Foods on The Travel Channel.

I like Andrew Zimmern, host of the Travel Channel’s Bizarre Foods.  However, I take issue with the excuse he used when justifying his hunt for sandhill cranes.  He joined some hunters in Tennessee in order to bag one for his show.  He claimed the birds ravaged farmer’s fields and drove away ducks and geese.  Supposedly, these factors were a sound reason for controlling their numbers.  This is pure bullshit.  Farmers have already harvested most of their crops by late fall–the time of year when cranes travel through Tennessee.  Ducks and geese co-existed with cranes for millions of years before man ever entered North America.  Hunting cranes is not a necessary policy for managing their numbers.  Why can’t Zimmern just be honest and admit he wants to kill the birds because they taste good?

Another pet peeve I have is hunters who claim they are “harvesting” an animal.  Harvest means picking an apple or an ear of corn.  Using the word “harvesting” as an euphemism for killing is just dishonest.  To “harvest” an animal usually means shooting it, and I’m pretty sure the animal feels lots of pain when the bullet or shotgun pellets are tearing through their nerves.  I’m not against hunting for food.  I enjoy the flavor of wild game meat and would eat nothing but this healthy alternative, if I had the opportunity.  Why can’t people just be honest about it?  Hunting is killing…not “harvesting.”

I Lured a Barred Owl (Strix varia) to My Yard

April 18, 2014

I have never seen a great horned owl (Bubo virginianus) in the wild, but  I may have heard this owl’s call once or twice.  So I decided to perform an experiment to see if I could lure one to my yard.  Owls are aggressively territorial and will confront trespassing members of their own species.  Smaller species of owls are driven away or devoured.  On 3 consecutive evenings, I opened a back window and played a recording of a great horned owl for about 10 minutes.  There was no response and I concluded there are no great horned owls in my neighborhood.  The next evening, after downing a few glasses of wine, I played a recording of a barred owl instead.  (http://www.allaboutbirds.org/guide/barred_owl/sounds)  I clicked on the link to the recording and had enough time to grab a bag of kitchen scraps for the compost pile before the recording began.  There was an immediate response from a barred owl in the woods behind my house.  I heard it while emptying the bag of used tea leaves, potato skins, and apple cores on the compost pile.  By triangulation, I estimated the bird was 20 yards from my back fence.  I went inside, looked out the window, and saw the owl land on a pine tree branch in the middle of my yard.  It was ready to rumble with the other interloping owl.  I was able to stand right under the branch and take a photo of the bird.

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The barred owl is on the 2nd branch from the ground to the right of the tree.  Click to enlarge.  The most notable feature when seeing this specimen up close was the large size of the eyes, built for excellent night vision.

Barred Owl (Strix varia) - Picture 4 in Strix: varia - Location: Florida, USA. Photo by Ashley Hockenberry.

Here’s a much better photo of a barred owl I found on the web taken by someone who knows more about photography than I do.

The barred owl is the only species of owl I’ve ever seen in Georgia, and I often hear their call which sounds like someone saying, “Who cooks for you; who cooks for you all.”  I frequently see road-killed barred owls on the highway–evidence they are abundant in the environment and fly too low at night while hunting rodents in the grassy medians.  Barred owls prefer forested swamps but seem just as home in suburban woodlots and second growth forests.  They are habitat generalists that have expanded their range in the face of advancing suburban sprawl.  They eat rodents, birds, rabbits, lizards, snakes, frogs, fish, and even crayfish.  I’ve seen barred owl pellets consisting of crayfish exoskeletons.

Barred owls have probably been the most common owl in southeastern North America for millions of years.  Their fossil remains are more abundant than any other species of owl in the fossil record of Florida, the southern state with the most Pleistocene-aged sites.  Barred owl fossil remains have been found in at least 10 sites in Florida.  The smaller screech owls (Otus asio) are the next most abundant owl in the fossil record, having been excavated from 8 sites in Florida and 1 in Georgia.  The larger great horned owls have been found in just 5 Florida fossil sites.  Barn owl (Titus alba) fossils have been found in 6 Florida sites and also several Carribbean sites.  Fossil remains of the long-eared (Asio otus) and the short eared owl (Asio flammeus) total just 4 sites in Georgia and Florida.  Fossil remains of burrowing owls (Athene cuniculara) were abundantly found but at just a single site in Florida.  There was a poorly known extinct species of owl living in Georgia during the Pleistocene that has yet to be named as a species.  (See:https://markgelbart.wordpress.com/2013/04/22/the-unknown-owl-of-pleistocene-georgia/)

I decided not to perform my experiment with a screech owl call because I assumed the presence of a barred owl this close to my house would prevent screech owls from occupying this territory.

Barred owls have expanded their range to the Pacific northwest where they are outcompeting the endangered spotted owl (Strix occidentalis).  Barred owls usually  kill or drive away their smaller cousins but occasionally they interbreed with them.  Spotted owls require old growth forests and mostly feed upon flying squirrels.  Barred owls are less picky about their habitat and prey and have invaded the spotted owl’s natural range, possibly thanks to human impact on the landscape.  To reverse this trend, federal wildlife officials killed 3600 barred owls in the Pacific northwest last year.  Reportedly, spotted owls have returned to areas they’d lost to barred owls.   Federal wildlife officials have spent lots of money saving spotted owls, and they didn’t want to see it go to waste because of the tougher, more adaptable barred owls.  I’m opposed to this disgusting policy.  It is not really certain man is responsible for the expansion of the barred owl’s range.  This ecological occurrence has not been adequately studied.  Barred owls may have eventually colonized the Pacific northwest with or without the presence of man.  Species have been driving other species into extinction ever since life evolved.

Zoo Cave, Taney County, Missouri

April 15, 2014

When I was a kid looking up information in an encyclopedia for a school project, I’d always get sidetracked and find something interesting while flipping the pages to the intended subject.    The same holds true today when I’m researching material for my blog, especially thanks to the thousands of  results produced by a typical internet query.  Probably half my blog articles originated from stuff I came across while looking up other stuff.  A few weeks ago, while researching my blog article about Pleistocene megafauna in northeastern North America, I reached for Bjorn Kurten’s Pleistocene Mammals of North America on my book shelf.  I was looking for Pleistocene-aged fossils sites in New York and New Jersey.  Much to my surprise, Kurten didn’t list any for those states.  Both states have lots of fossil sites but evidentally they were poorly documented in the scientific literature at the time this book was published in 1980.  However, as I was thumbing through the alphabetical order of the states, I was intrigued by a paragraph about Zoo Cave in southwestern Missouri.  Kurten stated the evidence found at this site suggested 2 climatic stages–a warm dry and a cool moist.  Kurten cited an obscure cave journal article published in 1975 as his source.  I was able to obtain a back copy of this journal for $10.

Taney County, Missouri where Zoo Cave is located.

Upon reading this article, I discovered the conclusion made by the original authors and repeated by Kurten was a wild overreach.  The majority of the fossil organisms found in this cave preferred cool moist environments, temperate climates, or are not restricted to any specific habitat.  The only mammalian species excavated here that preferred warm environments was the beautiful armadillo (Dasypus bellus).  However, since this article was published, fossils of this species have been found as far north as Indiana.  Modern armadillos found in North America can survive in cool climates as long as the ground isn’t frozen solid for long periods of time.  They stay in deep underground burrows during spells of sub-freezing temperatures and emerge on warm days to dig for worms and beetle grubs which are in the soil year round.  I can’t believe the authors of the study made their sweeping interpetation based on such flimsy evidence.  They assumed the occurrence of a warm dry climate phase based on a single species.

Zoo Cave did hold the remains of at least 81 flat-headed peccaries (Platygonnus compressus).  The cave was not a natural trap.  Instead, many generations of peccary herds used the cave as a shelter.  The green fractures found on many of the peccary bones probably resulted from peccaries trampling over their dead brethren.

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The top photo from the below referenced journal shows green fractures of peccary bones.  There’s no evidence they were gnawed upon.  Herds of peccaries probably just trampled over bodies of their kin while staying in the cave.  The bottom photo is probably of a natural artifact, not a human made scraper.

A small dire wolf skeleton was also found in the cave.  Eight species of smaller animals that no longer occur this far south or east had a range that extended to this cave during the Ice Age.  They include the fox snake, arctic shrew, masked shrew, southern bog lemming, red backed vole, meadow vole, porcupine, and plains pocket gopher.

Fox Snake

Fox snake (either Elaphe vulpina or E. gloydi).  Fossils of this species were found in Zoo Cave.  It is a type of rat snake that no longer ranges this far south–evidence of cooler climate at the time of deposition.

The spectrum of animals found here suggests a local Ice Age environment that consisted of a mixed boreal and hardwood forest with some prairie openings, not unlike that found in modern day southern Minnesota, but it likely has no exact modern analogue. Fossil evidence of elk, fox squirrel, woodchuck, beaver, red fox, black bear, coyote, and raccoon was excavated from the cave.  The fox snake and 6-lined race runners preferred the prairie openings, but most of the species are most often found in temperate woodlands.

Zoo Cave is located in Mark Twain National Forest where an oak-hickory climax forest grows on good soils and cedar glades are found on poor soils.  The cave was discovered by 2 brothers over 40 years ago.  The cave passages total 1100 feet long.  The authors of the article found fossils in just about every area of the cave but intensively excavated just a part named “bone passage,” leaving the rest for future paleontologists.   As far as I can determine from available literature, this cave is little known and would be worth re-examination.

There is an interesting table in the journal article about Zoo Cave comparing northern and western faunal elements recovered from this cave with those found in 2 other Missouri Caves. Fossils of snowshoe hares and red squirrels were found in Bat Cave and Crankshaft Cave.  These 2 species no longer occur in this state.  Porcupine fossils  were also found in Crankshaft Cave, but fisher fossils were found in Bat Cave.  The latter preys upon porcupines.  Fossils of grasshopper mice, a western species, were  found in Crankshaft Cave.  The table lists a kit fox fossil as being recovered from Crankshaft Cave, but these remains probably represents the swift fox, a species also found west of Missouri today.

Swift fox (Vulpes velox) remains were found in Crankshaft Cave, Missouri.  This species no longer occurs this far east.  Its presence is evidence of an eastward extension of prairie habitat during the Ice Age.

Fossil sites as far east as Ohio, Kentucky, Georgia, and Florida provide evidence of an eastern extension of prairie fauna during the Ice Age.  There is a striking resemblance between fossils found in Missouri caves with those found in Welch Cave, Kentucky, indicating a similar type of environment covered a large swath of the midwest during the Ice Age.  (See https://markgelbart.wordpress.com/2012/09/12/the-kentucky-bluegrass-country/).

Reference:

Hood, Clark; and Oscar Hawksley

“A Pleistocene Fauna from Zoo Cave, Taney County, Missouri”

Missouri Speleology 15 (1) 1975

Extinct Pleistocene Ecomorphs of the Cougar (Puma concolor) and the Timber Wolf (Canis lupus)

April 11, 2014

Genetic evidence suggests all present day cougars found in North America descend from a population of the big cats that lived in northeastern South America 10,000 years ago even though the fossil record shows cougars did live in North America during the late Pleistocene.  Cougar fossils have been found in at least 15 sites in Florida and 2 in Georgia, and they date to between ~130,000 BP- ~12,000 BP.  Yet, cougars that lived in North America during the Pleistocene left no living descendents–apparently they became extinct along with most of the rest of the Pleistocene megafauna.  This seems odd because modern cougars are well adapted to prey on deer and small game that survived the end Pleistocene extinctions, and Pleistocene cougars did not significantly differ morphologically from modern cougars.

The Pleistocene cougar was a large ecomorph.  An ecomorph is defined as a local variety of a species whose appearance is determined by its ecological environment.  Pleistocene cougars averaged 5% larger than modern cougars.  The color of their coat is unknown but it may have been spotted.

Florida Panther & Cub

A Florida panther in captivity.  Cougar kittens are spotted–evidence they evolved from a spotted ancestor.  This particular adult has retained spots.  Pleistocene cougars in North America may have been spotted.  A Florida panther is the same species as a cougar.  It’s now not even regarded as a separate subspecies by most experts.

Rob Klein, the stupid looking asshole on the far right, is the jerk who killed this beautiful animal in Alberta, Canada. (His facial expression is reminicent of those seen on Nazi concentration camp guards during WWII.)  This cougar specimen weighed over 200 pounds.  This unusually large specimen is probably what the average size was for a Pleistocene male cougar.

Even the larger Pleistocene cougars should have been able to survive on white tail deer, a species that increased in numbers when competing megafauna prey species became extinct.  The reason why this cougar ecomorph went extinct is a mystery.  Perhaps this ecomorph was adapted to live in an environment where prey was not scarce, and there may have been a decades long delay before deer populations increased in response to the disappearance of other megafaunal prey species such as horse, llama, and peccary.  Maybe the last surviving Pleistocene carnivores, combined with human hunters, had no other alternate prey and therefore decimated deer populations, so that even this species declined to such low numbers that cougars had too little to eat.  The  cascade effect of losing so many prey species in the environment  almost doomed white tail deer as well because they were one of the few prey species left for predators to feed upon. The disappearance of the cougar from North America suggests a period of time when even white tail deer became scarce.  The genetics study does show that cougars must have been absent from North America for at least 1 breeding generation (about 10 years)  because there’s no evidence the South American founder population ever bred with the North American ecomorphs.  Recolonization of North America by cougars must have been rapid and probably occurred in less than 200 years whenever white tail deer populations rebounded.   Cougar bones have been found in early Holocene-dated archaeological sites–North America was not without cougars for long.

South American cougar populations have greater genetic diversity than those of North America.  There are 5 subspecies of South American cougars compared to just 1 in North America.  (Florida panthers are no longer considered by some to be a different subspecies.)  Florida panthers almost became extinct from inbreeding 20 years ago, but wildlife officials introduced 8 female cougars from Texas, and the population has since tripled.

Genetic studies show a similar history for the jaguar (Panthera onca).  This cat also disappeared from North America and most of South America following the extinction of the Pleistocene megafauna.  It too survived in a refuge located in northeastern South America.  This population eventually recolonized the rest of that continent as well as the southern parts of North America.  Man has probably stymied the further spread of this species.  The last stand refuge shared by cougars and jaguars was probably an area of rain forest uninhabited by man that retained enough game to support a significant population of predators.

The Pleistocene armadillo (Dasypus bellus) has been found to be genetically similar to the modern day 9-banded armadillo (Dasypus novemcinctus).  I hypothesize the modern species is simply a dwarf ecomorph of the larger Pleistocene species.  From a refuge located in South America this dwarf ecomorph has recolonized much of its former range.  This scenario is similar to that of the big cats mentioned above, but it occurred within written historical times. (See https://markgelbart.wordpress.com/2012/08/19/is-the-9-banded-armadillo-dasypus-novemcinctus-a-dwarf-mutation-of-the-pleistocene-species-dasypus-bellus/)

An Alaskan gray wolf.  Modern Alaskan gray wolves are not descended from the wolves that lived here during the Pleistocene.  Those wolves became extinct when the megafauna became extinct.  Instead, modern Alaskan wolves descend from wolves that recolonized the region some time during the Holocene.

The timber wolves living in Alaska during the late Pleistocene were a large ecomorph that also left no living descendents, according to the genetic evidence.  Their anatomical characteristics suggest they were a robust animal well adapted to hunt large now extinct megafauna.  Dire wolves (Canis dirus), common in the rest of North America, never ranged this far north, and the timber wolves living in Alaska then occupied the dire wolf niche.  The Alaskan timber wolf ecomorph became extinct when the Pleistocene megafauna disappeared.  The timber wolves currently living in Alaska descend from wolves that lived elsewhere in North America during the Pleistocene.

Cougars vs. Wolves–the latest updates

The age old war between cougar and wolf has been re-ignited since the latter has been re-introduced to the Rocky Mountains of the United States.  The Teton Cougar Project has recorded 5 cougar kittens killed by wolves.  Meanwhile, a mother cougar killed a yearling wolf and fed it to her kittens.  In Montana cougars have killed 2 adult radio-collared wolves.  In one case they were battling over an elk carcass, and the wolf was left uneaten.  In the other instance the cougar actively hunted, killed, and ate the wolf.

References:

Culver, M. et. al.

“Genomic Ancestry of the American Puma”

Journal of Heredity 2000

Leonard, J.A.; et. al.

“Megafaunal Extinction and Disappearance of Specialized Wolf Ecomorph”

Current Biology 2007

Morgan, Gary; and Kevin Seymour

“Fossil History of the Panther (Puma concolor) and Cheetah-like cat (Miracinonyx inexpectus) in the Florida Pleistocene

Bulletin of the Florida Museum of Natural History 1997

Locating Exactly Where Herds of Pleistocene Megafauna Grazed in the Georgia Piedmont Region

April 8, 2014

Some species of megafauna that used to live in southeastern North America required large expanses of grasslands.  Shady forests inhibited the growth of their favorite foods, though seasonally the grazers would move into the woods for acorns and berries.  However, closed canopy forests could not support herds of grazers that depended upon tons of grasses and forbs found only in sunny conditions.  The Columbian mammoth, bison, elk, horse, half-ass, and Harlan’s ground sloth were all denizens of open environments.  In the coastal plain of the southeast region, open environments were always common no matter the climatic stage.  During warm interglacials and interstadials, longleaf pine savannah predominated while deep forested swamps were restricted to river valleys or low areas.  And during cold stadials dry prairies with some thickets of scrub oak were the most common environment.  But in the piedmont and mountain regions of the south, conditions usually favor trees over grass.  Hilly terrain and abundant creeks act as natural firebreaks and without fire forests are likely to become the climax type of environment..  Yet, evidence from the fossil record, and accounts of early colonists prove that grazers lived in these regions as well.  I hypothesize megafauna grazers ranging in the piedmont region of the south were mostly found in areas with soils derived from ultramafic rock.  The following link is a geological map showing where surpentine barrens and soils derived from ultramafic rock can be found in the piedmont region.  I believe these areas supported most of the megafauna herds of grazers formerly found in the piedmont region. http://pubs.usgs.gov/imap/0476/plate-1.pdf

Mixed herd of bison and elk in Land Between the Lakes on the border between Kentucky and Tennessee.  Herds like this ranged into the southeastern piedmont region till about 1760, though they may have been absent during times of higher Indian occupation of the land.

Appalachian Trail, Wild Horses of Mt. Rogers

Horses can survive in wooded areas but they prefer grassy habitats.

Leaf Beetle - Diabrotica cristata

Western Leaf Beetle (Diabratica cristata).  It ranges over much of the western Great Plains region of North America, but relic populations of this species exist on serpentine barrens in the eastern area of the continent.

Soils derived from ultramafic rocks have low magnesium/calcium ratios, and they contain heavy concentrations of toxic metals leached from the rock.  (See:https://markgelbart.wordpress.com/2013/01/01/a-serpentine-barren-in-georgia-burkes-mountain/)  Grass is able to outcompete trees in these types of environments, especially when aided by the occasional fire.  They are referred to as barrens.  In some areas with lesser degrees of soil toxicity, they may support open woodlands.  They aren’t completely treeless, but there is enough space between the trees for grass and forbs to grow.  I suspect a barren hilltop where William Bartram, an 18th century naturalist, found the bones of bison, elk, deer, and human was Burke’s Mountain in Columbia County–a well known surpentine barren.  The geological map also shows ultramafic derived soils in the bottom third of Elbert County, McDuffie County east of Wrightsboro, the northern part of Wilkes County, Green and Taliaferro Counties,  Columbia County along Greenbrier Creek, a big swath of territory in Jasper-Putnam-and Monroe Counties, and in various areas around present day Atlanta.  In Alabama ultramafic soils cover much of Coosa, Chilton, Clay, and Cleburne Counties.  In South Carolina they are found in Abbeville, McCormick, and Greenwood Counties.  Many small areas with ultramafic soils have not been mapped.

Indian populations collapsed after 1600 when the tribes came into contact with DeSoto’s leftover pigs that went feral.  Many died when they contracted swine flu or trichinosis.  Later, Indian populations continued to decline because of their weak resistance to smallpox, measles, and alcohol–unwelcome gifts bestowed upon them by the British colonists.  The decrease in the human population allowed elk and bison, the only American megafaunal grazers to survive the end Pleistocene extinctions, to increase in the piedmont region during early colonial times because they were able to graze on abandoned Indian fields that provided additional habitat besides the natural barrens which were never suitable for cultivation.  This explains why early British colonists saw what they mistakenly thought was pristine wilderness.  Actually, wilderness was reclaiming land from a civilization in collapse.

Bison lived as far south as north Florida during early Colonial times, probably recolonizing the region for the first time in thousands of years.  Mark Catesby reported them foraging in the  morning and evening on the grasslands, but they spent the heat of the day in shady canebrakes near creek or river bottoms where they were easy to track in the mud.  Elk didn’t range as far south as the coastal plain during Colonial times, but an elk fossil has been found in Charleston, South Carolina.  Cool stages of the Pleistocene may have allowed elk to inhabit parts of the coastal plain, but no elk fossils have ever been found in Florida.  Elk probably never developed resistance to parasites that abound in frost free environments.

These open environments in the piedmont were also home to prairie chickens, upland sandpipers, common nighthawks, meadowlarks, and other birds that prefer relatively treeless landscapes.

Creationists Crap on Bill to Make Columbian Mammoth South Carolina’s State Fossil

April 4, 2014

African-American slaves correctly identified the first North America vertebrate fossils ever found in recorded history.  The specimens were excavated from land belonging to a South Carolina plantation owner who stupidly thought they were the bones of giants that died in Noah’s flood.  But the slaves recognized the teeth came from a species of elephant not too different from the beasts they knew so well from their homeland.  Mark Catesby, the naturalist discussed in my blog entry previous to this one, was able to confirm the identification because he had seen elephant teeth in an English museum.  The lily white world of paleontology during the 19th and 20th centuries had difficulty admitting that the earliest American pioneers in their field were black.

White politicians in today’s South Carolina’s state legislature still have difficulty swallowing some truths.  An 8 year old girl wrote a cute handwritten letter to Governor Nikki Haley, nominating the Columbian mammoth (Mammuthus colombi) as the state fossil because it was the first vertebrate fossil found in South Carolina.  She also noted South Carolina was 1 of just 7 states that didn’t have a state fossil. 

The concept of having a state fossil is trivial and silly, and the motion should have passed without controversy, but  2 anti-science Creationists have managed to crap all over the proposal.  Mike Fair voted against it because he thinks the Theory of Evolution shouldn’t even be taught as fact in public schools.  Kevin Bryant added a New Testament biblical passage to the bill and it got bogged down due to the possibility it would now be unconstitutional.  The national media picked up the story though most media outlets as well as the South Carolina legislature demonstrated great confusion between the woolly mammoth (Mammuthus primigenius) and the Columbian mammoth which were 2 completely different species.  The national spotlight shamed Mr. Fair into dropping his opposition to the bill, while Kevin Bryant withdrew his biblical passage amendment.  Meanwhile, the correct species of mammoth was inserted into the language of the bill.  The bill seemed headed for clear sailing, but Kevin Bryant  then inserted an Old Testament biblical passage into the bill and it is bogged down again.  He thinks the Old Testament passage will pass constitutional muster because so many different religions include the Old Testament as part  of their bible.  I’m not even going to waste time commenting on how stupid Mr. Bryant’s thought processes are.

 

 

Senator Kevin L. Bryant

 

 

 

Kevin Bryant, the mentally handicapped moron in the South Carolina legislature who wants to insert a bible passage into a bill making the Columbian mammoth the state fossil.

 

 

 Senator Michael L. Fair

 

 

 

Mike Fair, another idiotic redneck in the South Carolina state legislature , who thinks bible stories should be taught in science class.

Artist’s rendition of a Columbian mammoth.  This species ranged all over North America south of the ice sheets.  The woolly mammoth ranged as far south as Virginia and South Dakota, but its primary range was Beringia and Eurasia.  I suppose learning of the existence of 2 additional species of elephant-like animals in North America–the mastodon and gompothere–would make the heads of most members of the South Carolina legislature explode, and reporters would even get more confused.

I don’t often discuss the Evolution vs. Creation debate controversy on my blog because I think it is boring.  It’s like debating reality vs. some clumsily compiled fantasies written by ignorant religious fanatics thousands of years ago.  I think all religions are stupid, and the people who follow them completely shut down their brains and become zombie-like automatons.  The thought that people just stop thinking when they get inside a church is a little scary.  It’s also known as brainwashing.  The most popular religion in the United States is Christianity, but most Christians don’t even realize they are members of a very bizarre end-of-the-world cult.  I believe in what I can actually see…the facts, not some ridiculous fairy tales.  I got into trouble mentioning my opinion on The Fossil Forum message board where they have a rule against disparaging religion.  I think giving too much respect for religion is a major problem in this country.  Religion is a scam, and preachers are making millions of tax free dollars selling their garbage to the gullible.  The moderator at The Fossil Forum privately informed me that my opinion was an embarrassment.  I posted under my real name on that forum, and I’m proud that I tell the truth and never hide behind phony respect.  I will never post on that forum again.  I never like message boards with anal moderators anyway.  Anyone who feels the need to police what other people think needs to find a new hobby. 

Auspex (I don’t know his real name), the top moderator at the Fossil Forum website.  He’s the shmuck who told me my opinion about religion was an embarrassment.  I used my real name on that forum and feel no shame in my honest opinion.  This stupid fascist needs to find a new hobby.

Primeval Floods

April 1, 2014

Mark Catesby was a naturalist who spent time in Virginia, South Carolina, and the Bahamas between 1712-1726 with the exception of 3 years when he returned to England.  His specialties were botany and ornithology, and his accounts of the natural history of the south bridges the gap between those of John Lawson who was murdered by Indians in 1711 and those of the Bartrams who explored the region in the mid-18th century.  When Catesby resided in South Carolina, there were still mixed herds of elk and bison as far south as the piedmont region.  By the time William Bartram traversed the region, all he saw of these animals were the bones of specimens that had been killed years before.  Catesby often accompanied Indians on their hunts for bison, bear, and cougar.  He saw the region long before the ecosystem had been tamed and, in my opinion, spoiled.  In Catesby’s time, Europeans had settled just a narrow 5 mile strip along the coast, and much of the interior was wilderness thinly occupied by a declining Creek Indian population.

Circa 1680, European traders established a small post 4 miles south of present day Augusta, Georgia, and they gave it the name Savannah Town, not to be confused with the city of Savannah built on the coast of Georgia by order of General Oglethorpe decades later.  (The frequent use of the word, savannah, suggests an abundance of open grassy environments in these locations.)  The site of Savannah Town was as far as boats could travel up the Savannah River year round.  Twenty miles upstream, rocky cataracts prevented boat travel all year long, but near Savannah Town, sandbars intermittently formed, impeding boats for months at a time.  Indians traded deer skins , a leading export here till the late 18th century, for goods such as knives and iron pots.  However, the Indians didn’t understand the European concept of credit, and the European traders beat and enslaved Indians who didn’t pay off their debts.  This was in the days of indentured servitude when poor white people faced the same kind of punishment.  The Creek Indians retaliated by burning Savannah Town to the ground in 1715.  In response to this attack, the following year, traders and soldiers built Fort Moore on a nearby bluff overlooking a loop of the Savannah River.  Residents of Fort Moore witnessed an incredible flood in 1722 when, as if God wanted to wash away the wickedness of the Creek Indian vs. British merchant conflict, all of  New Savannah Town was destroyed.  The below passage is Mark Catesby’s description of this awesome and untamed act of nature.

“When great rains fall on the mountains, these rapid torrents are very sudden and violent; an instance of which may give a general idea of them and their ill consequences.

In September 1722, at Fort Moore, a little fortress on the Savannah River, about midway between the sea and the mountains, the waters rose 29 feet in less than 40 hours.  This proceeded only from what rain fell on the mountains, they at the fort having had none in that space of time.

It came rushing down the river so suddenly, and with that impetuosity that it not only destroyed all their grain, but swept away and drowned the cattle belonging to the garrison.  Islands were formed, and others joined to the land.  And in some places the course of the river was turned.  A large and fertile tract of low land, lying on the south side of the river, opposite to the fort, which was a former settlement of the Savannah Indians, was covered with sand 3 feet in depth and made unfit for cultivation.  This sterile land was not carried from the higher grounds, but was washed from the steep banks of the river.  Panthers, bears, and deer were drowned and found lodged on the limbs of trees.  The smaller animals suffered also in this calamity; even reptiles and insects were dislodged from their holes, and violently hurried away, and mixing with harder substances were beat in pieces, and their fragments (after the waters fell) were seen in many places to cover the ground.”

Map showing the location of New Savannah.  It was founded over 50 years before the better known modern city of Savannah, Georgia on the coast.

Flood of 1908 on Broad Street in Augusta, Georgia.  The city built higher levees after this one.  A flood of 1990 even breeched this, but it would have been much worse, if not for the construction of Clark Hill Dam upstream. 

It’s astonishing to realize this area didn’t even receive any rain, the flood resulting from storms that occurred many miles to the north.  Just imagine the aftermath of this flood: rotting corpses in the trees above, crushed animal parts strewn all over the ground, new islands formed, loops of the river completely rerouted, and much of the Fort’s food supply washed away.  Wow, what an example of nature’s fury.  In the Augusta area alone similar devastating floods occurred in 1796, 1840, 1865, 1887, 1888, and 1908, and this is just in recorded history.  But over the past 150 years, engineers have built drainage ditches, levees, and dams alongside and across every major river in Georgia, greatly reducing the frequency and intensity of floods, so a “freshet” like the one of 1722 is not likely to occur again as long as man maintains civilization.  This may be a good development for humans, but it has altered the natural environment in a way that has been detrimental to many species.  Below is an enumeration of the types of environments created or heavily influenced by primeval floods.

1. Canebrakes.  Floods that left standing water for any length of time killed trees by depriving them of oxygen, and thus opened up the canopy.  Floods also deposited sediment and greatly enriched the soil.  The combination of open sunny conditions with fertile soil led to the occurrence of vast stands of bamboo cane extending for many miles.  It seems counterintuitive, but soils especially rich in nitrogen host a low diversity of species, and canebrakes were an example of a single species occupying tracts of hundreds of square miles.  The bamboo canes provided forage for bison, feral livestock, and swamp rabbits, and during the Pleistocene would have fed mammoths and horses.  Bears and big cats liked to den in these dense thickets. (See:https://markgelbart.wordpress.com/2013/01/28/canebrakes-are-forlorn-landscapes/)

2. Buffalo Meadows. Mark Catesby found meadows where the grass grew 6 feet high.  It would be hard to find grass growing this tall on modern worn out soils in the south.  Settlers took advantage of the rich soils covered by bamboo cane and tall grass, converting them to field crops.  The yield was worth the risk of a once in 20 year flood.  Both these environments disappeared rapidly upon the onset of European colonization.

3. Bottomaland Forest.  Most of the modern day floodplains abandoned or left undeveloped have grown back to bottomland forests of sweetgum, mesic-loving species of oaks, sycamores, and loblolly pines.  On virgin soils enriched by floods, those trees grew to enormous size, much larger than most presently growing.

4. Sand Covered Patches.  I haven’t found anything abut this type of environment in the literature, but Catesby’s account of the 1722 flood mentions a barren area of river deposited sand 3 feet thick.  I hypothesize these areas gradually developed soil on top of the sand where young stages of forest succession would grow.  Perhaps because of the low soil nutrients, these patches stayed in scrub and brier for prolonged periods of time and would have attracted rabbits, not unlike the original environment of Coney Island, New York.

5. Oxbow Lakes.  Floods created cut-off meanders–habitat for fish that preferred lake over river.  Modern day dams have eliminated spawning grounds for once abundant sturgeon and other species. 

An oxbow lake forms when a meander of the river gets cut-off.

Events similar to the flood of 1722 explain how some fossil deposits originated.  Drowned animals and downed trees rapidly became covered in sediment.  Floods also destroyed fossil deposits by washing sediment downstream.

Floods were much less common during Ice Ages because the climate became more arid.  Floods were more common during interstadials and interglacials.  The time periods between 15,000 BP-12,900 BP and again from 11,000 BP-6,000 BP were ages of superfloods in the south.  Geologists have discovered evidence of super meanders in river valleys and large sandbars known as scrolls that date to these time periods when storms were stronger than those of today, probably due to rapid deglaciation releasing so much precipitation into earth’s atmosphere.

References:

Elliott, David; and Roy Doyou

“Archaeology and Historical Geography of the Savannah River Floodplain near Augusta, Georgia”

University of Georgia Lab of Archaeology Series #22 1981

Feduccia, Alan

Catesby’s Birds of North America

University of North Carolina Press 1985