The Reddick Fossil Site in Marion County, Florida

November 26, 2014

One could almost refer to the Reddick Fossil Site in Florida as Rancho La Brea east.  It’s one of the richest eastern sites in species diversity, but nevertheless falls far short of Rancho La Brea’s treasure chest of fossils.  At least 147 species of vertebrates were recovered from Reddick compared to 231 from Rancho La Brea and the latter also far surpasses the former in quantity. Moreover, Rancho La Brea is still being excavated.  The Reddick Fossil Site was an abandoned limerock quarry excavated during the early 1960’s.  The Pleistocene topography consisted of limesink lakes and caverns with a soil chemistry that helped preserve the bones of many animals.  Owls roosted in the caves during the Pleistocene, and bones from the small mammals and birds they ate were found in their fossil pellets.  The composition of species shows that a wide variety of habitats occurred locally, including woodland, grassland, and wetland.  The fossil remains are thought to date to between ~200,000 BP- ~114,000 BP.  The presence of glyptodont, vampire bat, ocelot, and giant tortoise is evidence of a climate at least as warm as today’s Florida, even though this period of time includes the Illinois Ice Age.  This is the only site in southeastern North America where ocelot fossil remains have been found.  Only 32 of the 147 species are extinct.  Many of the large mammals were probably overhunted by man into extinction, and we know for sure passenger pigeons were.  However, some of the bird extinctions were local species that became extinct during marine high stages of the Sangamonian Interglacial when much of their terrestrial habitat was lost to high sea levels.  The following is the Reddick Fossil Site faunal list from the below referenced work.  * denotes extinct species.  + indicates an extant species no longer native to Florida.  The remarkable thing about this list is how few reptiles have gone extinct.  This suggests little environmental change in this region over the past 200,000 years.  (I’m not including the scientific name for most of these entries.  I feel lazy today and it’s almost a holiday.  Happy Thanksgiving.)

Map of Florida highlighting Marion County

Marion County, location of 1 of the best Pleistocene fossil sites in southeastern North America.

Greater siren

Mud siren

Ambystoma sp. (a type of salamander)

eastern spadefooted toad

oak toad

common toad

narrow-mouthed toad

tree frog sp.

leopard frog

Pseudemys sp. (a type of slider/cooter turtle)

box turtle (Terrepene carolina putnami)–an extinct subspecies but extant species

gopher tortoise

*medium-sized land tortoise–Hesperotestudo incisa

*giant land tortoise–H. crassicutata

soft-shelled turtle

green anole lizard

eastern race runner

5-lined skink

common glass lizard

Florida worm lizard

eastern ring-necked snake

mud snake

yellow-lipped snake

eastern hog-nosed snake

southern hog-nosed snake

rough green snake

black racer

coachwhip snake

indigo snake

king snake

corn snake

rat snake

pine snake

crowned snake

brown snake

garter snake

coral snake

pygmy rattlesnake

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All of the species of snakes found at the Reddick fossil site were still relatively common when Columbus reached North America

eastern diamondback rattlesnake

alligator

pied-billed grebe

*extinct grebe, a diver in the podiceps genus

mottled duck

pintail duck

shoveler

blue-winged teal

green-winted teal

ring-necked duck

*extinct condor–Gymnogyps amplus

turkey vulture

*extinct vulture–Coragyps occidentalis

Cooper’s hawk

sharp-shinned hawk

red-tailed hawk

red-shouldered hawk

peregrine falcon

sparrow hawk

caracara

quail

*extinct quail–Neotyx pennisubali

turkey

Virginia rail

sora

*extinct rail–Porzana auffenbergi

yellow rail

*extinct rail–Laterallus guti

*extinct coot–Fuliza merm

common crow

fish crow

blue jay

*extinct jay–in protocitta genus

house wren

*extinct wren–Gasthothanus brevs

maryland yellowthroat

cowbird

red-winged blackbird

grackle

eastern meadowlark

rufous-sided towhee

Henslow’s sparrow

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Henslow’s sparrow.  This species prefers weedy grassland habitat.  Ducks and rails prefer wetlands.  Passenger pigeons and woodpeckers need woodlands.  The composition of birds reflects varied habitats near this locality during the Pleistocene.

killdeer

lesser yellowlegs

common snipe

*passenger pigeon

mourning dove

barn owl

screech owl

burrowing owl

barred owl

yellow-shafted flicker

red-headed woodpecker

eastern kingbird

purple martin

*extinct swallow–Tachycinctus spelodytes

oppossum

*vampire bat–Desmodus stockii

southeastern myotis

red bat

Florida yellow bat

Brazilian free-tailed bat

*Wheatley’s ground sloth–the evolutionary ancestor of Jefferson’s ground sloth

*Harlan’s ground sloth

*Beautiful armadillo

*pampathere–a giant armadillo

*glyptodont

marsh rabbit

cottontail rabbit

southern flying squirrel

undetermined squirrel in scurius genus–probably a gray squirrel

southeastern pocket gopher

rice rat

harvest mouse

old field mouse

cotton mouse

Florida mouse

golden mouse

cotton rat

wood rat

pine vole

round-tailed muskrat

*Florida bog lemming–Synaptomys australis

*dire wolf

+coyote

gray fox

*Florida spectacled bear–Tremarctos floridanus

black bear

raccoon

+hog-nosed skunk

spotted skunk

striped skunk

+jaguar

cougar

+ocelot

aka, the dwarf leopard,

Reddick is the only fossil site in southeastern North America where remains of an ocelot have been found

bobcat

saber-tooth–Smilodon fatalis

mastodon

mammoth

+horse

*tapir

*long-nosed peccary

*flat-headed peccary

*large-headed llama

*stout-legged llama

white-tailed deer

bison

Reference:

Gut, James H.; and Clayton Ray

“The Pleistocene Vertebrate Fauna of Reddick, Florida”

Quarterly Journal of the Florida Academy of Science 1964

 

African Hunting Dogs Lived in North America during the Middle Pleistocene

November 21, 2014

The African hunting dog (Lycaon pictus meaning painted wolf) stars in many nature documentaries, but few people are aware that close relatives of this species formerly lived across Eurasia and even into North America.  At least 2 different species occurred in North America during the middle Pleistocene between ~1.5 million BP-~300,000 BP.  Fossil remains of Xenacyon lycaonoides were excavated from 2 sites in Alaska and 1 in the Yukon.  The first paleontologist who looked at these specimens misidentified them as dhole (Cuon alpinus) teeth, but a more recent examination of the dentition determined they belonged to a canid more closely related to African hunting dogs.  These scientists also examined the only other dhole fossils found in North America (from San Josecitos Cave in Mexico) and did confirm that identification.  The other American species of canid closely related to the African hunting dog was Xenacyon texanus, and it’s known from just 1 fossil locality–Rock Creek in northwest Texas.  The sum total fossil remains of X. texanus are part of 1 jaw with teeth, a leg, and a shoulder fragment.  Based on this scant anatomical material, scientists believe X. texanus was slightly larger the X. lycaonoides which was about the size of a timber wolf.

Photo: An African wild dog with pups

Two extinct and little known species of canid, closely related to present day African hunting dogs, lived in North America during the middle Pleistocene.

Dholes tearing up a deer.  Fossil remains of this canid have been found from just 1 site in North America.  It originated in Asia, yet it inhabited Mexico during the late Pleistocene.  It must have been more widespread in North America than the fossil record indicates.

Wolf fossils in North America are much more common than those of X. lycaonoides, X. texanus, and Cuon alpinus.  This suggests these species of hunting dogs didn’t compete well with American wolves.  During the middle Pleistocene X. texanus would have occupied the same ecological niche as Armbruster’s wolf (Canis armbrusteri), the probable evolutionary ancestor of the dire wolf (Canis dirus).  Nevertheless, X. texanus did live in North America long enough to have evolved into a different species from X. lycanoides.  Obviously, they were more widespread and successful than the fossil record indicates.  It’s possible this species persisted into the late Pleistocene but was restricted to regions where their remains were not likely to be preserved.  The only dhole fossils found in North America were discovered in Mexico, yet this species originated in Asia, crossed the Bering landbridge, and must have occupied large areas of North America before colonizing Mexico.  Dholes co-existed with dire wolves and timber wolves (Canis lupus) in North America for some undetermined length of time.  The oldest dire wolf fossil dates to 252,000 BP (from a uranium-series dated deposit in South Dakota).  Timber wolves crossed the Bering landbridge 100,000 years ago and co-existed with dire wolves in western North America until the end of the Pleistocene.  It’s not known when dholes crossed the Bering landbridge.  Timber wolves and dholes are not known from the fossil record of southeastern North America.  I think dire wolves kept these other big game-hunting canids from occupying this more wooded region where prey was less abundant than on the grassy plains of the west.

The Rock Creek Fossil Site

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Rock Creek, the only known fossil site where Xenocyon texanus has been found, is located just north of Plainview, Texas, represented by the dot on this map.

The Rock Creek fossil site is located just north of Plainview, Texas.  This is the only locality where remains of X. texanus have ever been found.  E.L. Troxell excavated this rock quarry and published his findings in 1915.  Along with the rare canid, he found the remains of gopher tortoise, giant tortoise, Harlan’s ground sloth, glyptodont, Imperial mammoth, flat-headed peccary, camel, llama, Soergel’s musk-ox, and horse.  He identified the remains of another canid as dire wolf, but he was probably in error.  The geological formation where these fossils were found is thought to be no younger than 400,000 years BP.  Dire wolves probably didn’t evolve yet, so the canid remains probably should be referred to as Armbruster’s wolf.

The composition of species excavated from Rock Creek suggests the region during this climatic phase consisted of arid grassland and scrub with milder winters than those of today.  Some scientists assume it was frost free due to the presence of giant tortoise, but I believe this species could survive light frosts.  Although winters were warmer then, it’s not safe to assume there were no frosts.  The horses, camels, and peccaries likely served as dinner for X. texanus.

References:

Tedford, Richard; et. al.

“Philogenetic Systematics of North American Fossil Caninae (Caninae: canid)”

Bulletin of the American Museum of Natural History 2009

The Pleistocene Box Turtle (Terrapene carolina putnami)

November 18, 2014

I self torture myself every Wednesday: I go in my backyard and do 150 pullups, jogging in place between sets, and I follow this exertion with yardwork such as cutting the grass with a scythe or chopping firewood with a dull axe.  (Lawnmowers and chainsaws are noisy and unpleasant and I use neither.)  Three weeks ago while torturing myself, I discovered a male box turtle (Terrapene carolina) sitting on the edge of a shallow burrow consisting of leaf litter and pine straw.  I didn’t think this would be sufficient cover to protect a cold blooded reptile from forthcoming frosts.  Yet, this turtle was still alive after the first frost of the year.  I perused the scientific literature and learned from 1 study that the average depth of a box turtle’s winter burrow in Ohio is only 2 inches, though some burrow as deep as 7 inches.  Snow further insulates them.  Box turtles range as far north as Maine and apparently they can survive when their body temperatures fall below freezing.  However, winter freezing is their leading cause of mortality.  Hard winters diminish their populations to some degree.

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A male box turtle that may spend the winter in my backyard.  Male box turtles have red eyes.  Females have yellow eyes.

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Note the burrow into the leaf litter and pine straw behind the turtle. Despite their terrestrial existence, box turtles are more closely related to aquatic turtles than land tortoises.

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Also note how shallow this burrow is.  Box turtles can survive hard freezes covered by just 2 inches of leaf litter and/or soil.

Various climatic fluctuations during the Pleistocene isolated populations of box turtles.  These changing conditions resulted in the regional variations in box turtle morphology evident today.  There are 6 recognized subspecies of eastern box turtle: the eastern (T. c. carolina), the Florida (T.c. bauri), the 3-toed (T.c. trungus), the Gulf Coast (T.c. major), the Mexican (T.c. mexicana), and the Yucatan (T.c. yucatan).  Moreover, there was a large extinct species (T.c. putnami), known from Pleistocene fossil sites.  All of these subspecies readily hybridize on the borders of their ranges.  A late herpetologist, William Auffenberg, and others hypothesized T.c. putnami preferred warm coastal grasslands, while T.c. carolina inhabited forested landscapes.  Accordingly, fossil remains of T.c. putnami could be used as evidence that a particular fossil site was of an interglacial age, and the presence of T.c. carolina was evidence a specific site was of glacial age.  But some remains of T.c. putnami were found at the Jones Creek fossil site in Missouri which dates to a climatic phase when jack pine and grass dominated the local flora.  Jack pine no longer occurs south of Michigan, and its presence in Missouri is evidence of a cooler climate than that of today.  I don’t believe Dr. Auffenberg’s hypothesis is valid.  T.c. putnami was widespread during the Pleistocene and likely well adapted to both glacial and interglacial conditions.

Partial carapace of the extinct subspecies of box turtle, T. carolina putnami.  Too bad the colors have faded away.

A recent comprehensive study of box turtle morphology and genetics determined that there was no evidence for the existence of the Gulf Coast subspecies, T.c. major.  Instead, the authors of this paper suggest box turtles found on the Florida panhandle, thought to be this subspecies, are descended from hybridization between the eastern subspecies, T.c. carolina, and the extinct subspecies,  T.c. putnami.  This would explain the larger size of Gulf Coast box turtles compared to other subspecies.  For some undetermined ecological reason the once widespread Pleistocene ecomorph of box turtle still occured as a relic population in this region, and the survivors hybridized with another now more common subspecies.

Box turtles are amazing survivors.  They are omnivorous, capable of eating any plant matter such as fruit, flowers, and fungi; and animal matter including insects, worms, snails, birds’ eggs, and carrion.  And they can survive scarcity of food because they have slow metabolisms.  They can live to be 100 years old and can regenerate when severely burned.  Females can mate once and lay fertile eggs for 4 years.  Box turtles survived millions of years of climatic fluctuations and still live and can be found in my backyard.

References:

Austin, Jones; et al

“Morphological and Molecular Evidence Indicate that Gulf Coast Box Turtles (T.c. major) are not a Distinct Evolutionary Lineage in the Florida Panhandle”

Biological Journal of the Linnean Society 2011

Claussen, Denis; et al

“Hibernation in the Eastern Box Turtle, Terrapene Carolina

Journal of Herpetology 25 (3) 1991

The Destruction of a Beautiful Kettle Lake led to the Origin of JP Morgan-Chase Bank

November 13, 2014

Kettle lakes are common geological formations found in North America in any region once covered by a glacier.  When glaciers recede they often leave large chunks of ice behind.  Both wind and water borne sediment covers these blocks of ice, temporarily insulating them, but eventually the ice melts and forms a lake.

Diagram showing how a kettle lake forms.

20,000 years ago, the edge of a mighty glacier advanced as far as what today is Manhattan Island, New York.  A narrow strip of unglaciated land, about 50 miles wide, existed on the continental shelf between Manhattan and the Atlantic Ocean.  After the glacier receded it left a kettle lake behind on the southern end of Manhattan.  The lake held clear glacial meltwater and was continuously fed by underground springs.  It was 70 feet deep–evidence the block of ice left behind had been quite large.  For thousands of years, Indians used this lake as a source of freshwater because the rivers surrounding Manhattan are tidal in nature and too salty to be potable.  An Indian settlement existed on the southwestern edge of the lake in 1604 when the Dutch first established a colony on Manhattan.  The Dutch called the lake “Koelch,” meaning small body of water, but when the English took over the island, the word was mispronounced, and thereafter was called “Collect Pond.” A steep 110 foot tall hill, known as Bayard’s Mount, occurred on the north side of Collect Pond, and another steep hill, Kalch Hoek, bordered the west side.  A freshwater marsh existed to the south of Collect Pond, and 2 creeks served as outlets for the kettle lake’s overflow.  Lispenard Creek drained into the Hudson River and Old Wreck Brook drained into the East River.  Fish likely colonized Collect Pond through these creeks.  Species of fish recorded to have lived in Collect Pond included pumpkinseed sunfish, redfin pickerel, eel, and killifish. Collect Pond was a beautiful and valuable natural resource.  It provided fresh drinking water for all of Manahattan for almost 200 years, as well as winter ice skating, and summer recreational fishing.  Man then turned this heaven into hell.

File:Collect Pond-Bayard Mount-NYC.jpg

A portrait of Collect Pond painted in 1798 by Archibald Robertson.  The weeping willow is not a native species and must have been planted early in the century.  After  poison from a tannery polluted the pond, developers filled it in with dirt from the hill (Bayard’s Mount) in the foreground.  That hill also no longer exists.

Circa 1800, the stupid greedy owner of a tannery factory was responsible for dumping tannins into Collect Pond, poisoning New York City’s drinking water.  Because Collect Pond no longer provided drinkable water, city leaders decided just to fill in the lake with dirt from the beautiful surrounding hills, thus destroying this once pristine site forever.  They called this leveled land “Paradise Square,” but within decades it transmogrified into the infamous 5 Points neighborhood depicted in the violent movie Gangs of New York.  To make matters worse, organic plant material from the fill material rotted away, causing parts of the neighborhood to sink.  It was a muddy, disease-ridden slum.  Anybody with any money at all moved away, leaving the neighborhood populated by poor Irish immigrants and freed African-Americans.  Circa 1900, city leaders condemned the neighborhood and replaced it with the city municipal building where justice and injustice are still dispensed by the court.  (Other buildings and parking lots occupy the rest of the space.)

The Manhattan Municipal Building towers 25 stories high, with an additional 15 stories on the center spire. (Amal Chen/The Epoch Times)

The New York City Municipal Building now stands where Collect Pond used to be. 

 

 Aaron Burr was the Vice-President of the United States between 1800-1804.  In 1808 he responded to the ecological disaster of Collect Pond by founding the Manhattan Water Company.  His stated goal was to bring water from upstream to downtown, but instead he used the assets to start JP Morgan Bank.  The city eventually built an aqueduct to bring water from a source off the island.  Aaron Burr is best known for his duel with Alexander Hamilton.  Burr fatally wounded Hamilton in 1804.  Hamilton was the Secretary of the Treasury and a member of Thomas Jefferson’s cabinet.  Fighting duels was a childish custom.  Imagine if Joseph Biden challenged Hillary Clinton to a duel.  JP Morgan is still run by childish crooks, but at least they don’t fight duels.

File:Hamilton-burr-duel.jpg

Portrait of the duel between Aaron Burr and Alexander Hamilton in 1804 drawn by J. Mund.  Aaron Burr founded JP Morgan for the purpose of funding a project to supply fresh water to New York City after Collect Pond was poisoned.  This portrait is not accurate.  The seconds had their backs turned so they wouldn’t have to testify in court as witnesses.

Reference:

Sanderson, Eric

Mannahatta: A Natural History of New York City

ABRAMS 2009

Georgia’s National Champion Trees

November 10, 2014

The nice trees I observed on Berry College campus last week inspired me to study the inventory of Georgia’s National Champion Trees published by the Georgia Forestry Commission (available online http://www.gfc.state.ga.us/forest-management/champion-tree-program/).  Georgia has 20 national champion trees.  Foresters measure the circumference at 4.5 feet above the ground + height + crown width to determine whether a tree is a champion of its species.  Some species have a range that is restricted to Georgia, so of course, the national champion of that species would be found in state.  The Georgia plume (Elliotia recemosa) is a small rare tree known from just 9 sites in the Georgia sandhills.  The largest known Georgia plume is in Tattnall County and is 47 feet tall with a diameter of a foot.

Other species have a limited regional range but are most common in Georgia, so the champion of that species would be expected in state.  Georgia oak (Quercus georgiana), first discovered on Stone Mountain in 1840, is a species of red oak that grows on rocky outcrops in the southern Appalachians.  The national record Georgia oak is found in Clarke County and is 59 feet tall with a diameter of just over 2 feet.  The Oglethorpe oak (Q. oglethorpensis), a species of white oak not recognized till 1940, includes a population of less than 1000 specimens in disjunct locations primarily on the Georgia Piedmont but also in Mississippi and South Carolina.  The record tree of this species is found in Oglethorpe County and is 64 feet tall with a diameter of over 3 feet.  Nutmeg hickory (Carya myritieformis) is another regionally rare tree with disjunct populations.  The largest known specimen is found in Floyd County and is 115 feet tall with a diameter of about 2 feet.

Some species of trees are fairly common throughout the southeastern coastal plain, but the largest specimens are found in Georgia.  Ogeechee lime (Nyssa ogeche), a tupelo with an edible fruit, is most common in Georgia.  The largest known is found in Toombs County and is 45 feet tall with a diameter over 6 feet.  Swamp privet (Foresteria acuminata), a member of the olive family, grows throughout the southeastern coastal plain.  The largest known specimen, also found in Toombs County, is 47 feet tall with a diameter of 11 inches.  Chalk maple (Acer leucoderma) is a rare regional tree found on the inner coastal plain and piedmont.  The largest specimen is found in Greene County and is 64 feet tall with a diameter of a foot.  Florida maple (Acer barbatum) is a little more widespread than chalk maple.  The largest known Florida maple is found in Floyd County and is 91 feet tall with a diameter of almost 4 feet.  May hawthorne (Crataegus aestivalis), produces a fruit used in making jelly.  The largest known is found in Haralson County and is 40 feet tall with a diameter of over 1 foot.  Viburnum possumhaw (V. nudem) is another regional borderline shrub with a record specimen found in Georgia.  The largest known is found in Oconee County and is 33 feet tall with a diameter of 4.4 inches.  Aloe yucca (Yucca aloensis) grows in coastal scrub along the southeastern coast as far north as New Jersey.  The largest known is found in Brantley County and is 14 feet tall with a diameter of 6 inches.

Myrtle oak (Q. myrtifolia) ranges mostly in Florida but the northernmost population in Camden County, Georgia holds the record specimen which is 36 feet tall with a diameter of 9.5 inches.

The most impressive national record trees in Georgia are from species found across most of eastern North America.  The largest red mulberry (Morus rubra) is found 20 minutes from my house in Richmond County.  It is 54 feet tall with a diameter of over 7 feet–truly an impressive tree harking back to primeval times.

This national champion red mulberry tree is located about 20 minutes from my house in Richmond County.

A post oak (Q. stellata) in Jackson County is 86 feet tall with a diameter over 6 feet.

The national champion post oak is in Jackson, County, Georgia.

National champion Ogeechee Lime Tupelo in Toombs County.

A southern red oak (Q. falcata) in Upson County is 137 feet tall with a diameter of 9 feet.  Unfortunately, there’s no photo of it online.  An eastern red cedar (Juniperus virginiana) growing in a Coffee County cemetery is 54 feet tall with a diameter of over 6 feet.

National champion Eastern Red Cedar growing in the Lane Hill United Methodist Church Cemetery, Coffee County, Georgia.

The largest Alabama black cherry (Prunus serotina alabamensis), a subspecies of black cherry, is found in Floyd County and is 49 feet tall with a diameter of 9 inches.  This is much smaller than the state record black cherry found in Ellijay which is 83 feet tall with a diameter of over 5 feet.

Georgia has some champion specimens of common borderline shrubs too.  The largest flatwoods plum (Prunus umbellata) is found in Union County and is 43 feet tall with a diameter of 11 inches.    The largest smooth sumac (Rhus glabra) is found in Twiggs County and is 52 feet tall with a diameter of 11 inches.  The largest mountain laurel (Kalmia latifolia) is found in Fannin County and is 20 feet tall with a diameter of almost 20 inches.  The largest buttonbush (Cephalanthus occidentalis), favorite food of the mastodon, is found in Screvin County and is 22 feet tall with a diameter of 5 inches.

Some of the most impressive trees in Georgia are not national record trees.  Below are photos of a few.

Georgia’s state champion black oak is located next to a convent in Fulton County.  William Bartram walked through a forest of gigantic oaks, some larger than this.  Too bad, pioneers destroyed that forest.

Georgia’s state record eastern cottonwood also located in downtown Atlanta.

Georgia’s state record beech is located in Lawrenceville, Georgia where my grandfather lived until he was 16.

The 2nd highest scoring trees in Georgia are bald cypresses.  

The highest scoring tree in Georgia is this live oak in Ware County.

The black oak growing next to the convent is over 7 feet in diameter.  This is not as large as many of the black oaks William Bartram observed in a 7 mile long forest he traveled through in 1775 (See: http://markgelbart.wordpress.com/2011/04/11/william-bartrams-magnificent-forest/)  Some of those trees measured 11 feet in diameter.  Loggers destroyed most of Georgia’s forests between 1865-1945.  The primeval forests prior to the Civil War undoubtedly held specimens larger than today’s state and national champions.  However, we are living during a climatic phase favorable to the rapid growth of trees.  The largest tree specimens lived during interglacials and interstadials when CO2 concentrations and precipitation levels were high.  If we preserve enough green space on fertile ground and allow remaining old growth forests to remain intact, there is hope that trees such as Bartram encountered may grow once again.

Berry College Campus Again

November 6, 2014

I daydream about living in Georgia when it was a wilderness unmodified by man, and I spend a lot of time thinking about the flora and fauna as it used to be.  So it’s nice when I get a chance to take a real stroll in nature, even if it is just the ruined remnants.  My favorite accessible natural area is Berry College Campus.  I always see more wildlife there than anywhere else I’ve ever visited.  Deer are abundant here but I couldn’t get any decent photos of them yesterday.  The bird life is varied: bald eagles, peregrine falcons, turkeys, Canadian geese, crows, killdeer plovers, bluebirds, pileated woodpeckers, and many others.  Like the deer, the birds didn’t want to cooperate with my camera either.  I had time for just a short walk yesterday and found some interesting trees.  Trees are much easier to photograph than animals.

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A view of Lavender Mountain in the background.

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I think this southern red oak, also known as Spanish oak, had a diameter of about 4 feet.

I was impressed with a southern red oak (Quercus falcata) that I had found.  It appeared to have a diameter of about 4 feet at human shoulder height.  But then I looked up the record.  Georgia has the national champion southern red oak in Upson County with a diameter of about 11 feet at 4.5 feet above the ground.  Wow!  I’d like to see that one.

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Montane chestnut oak.  Also pretty thick.

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The same tree as above from a different angle.  Note how twisted it is at the base.

I think this montane chestnut oak (Q. prinus) had a diameter of at least 4 feet, but it was hard to judge because of the twisted shape.  The state record montane chestnut oak tree in diameter is found in Fulton County and it is between 5 to 6 feet.  This tree might come close to that tree in circumference.  I’ll have to bring a tape measure with me next time I visit Berry College campus.

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White oak with a diameter of about 4 feet.

The white oak (Q. alba) pictured above doesn’t even come close to the Georgia state record white oak which is found in Fayette County and is at least double in size.

This is the Georgia state record white oak.  It’s double the size of the specimen I saw yesterday.

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Note the squirrel’s nest up in this white oak tree.

The squirrels are happy with all the oak trees on Berry College Campus.  Fox squirrels are listed as a species that occurs on the Berry College Wildlife Management Area, but I’ve only seen gray squirrels.  I won’t believe they really have fox squirrels here until I see one myself.

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This view from Little Texasville Road in Berry Wildlife Management Area.  I love this kind of landscape…big old trees surrounded by open grassland.  I envision Pleistocene landscapes in Georgia resembling this.  Just add some bison, horses, and mammoths to this scene.

The Berry WMA located behind Berry College Campus is the largest wildlife management area in Georgia.  This time of year, hikers aren’t supposed to walk on the trails.  Hunters might accidentally shoot them.

 

 

Pleistocene Ravens (Corvus corvax)

October 31, 2014

Halloween is my favorite holiday, but this year I’m not in the mood.  My father slipped into a coma and died last week.  That real horror far overshadows the artificial scares of Halloween and makes them even seem kind of silly.  It had been shocking to observe the steady decline of a man who went from being able to play 2 hour tennis matches in 100 degreee F heat to someone barely able to make it from the living room to the bathroom.  The aging process is a real monster that can not be stopped.  We were able to give my dad a proper burial, but that is a luxury ancient humans didn’t always have.  Humans are part of the natural world, and for many other organisms our bodies are just a source of protein.  Pleistocene humans no doubt often died from accidents while hunting.  If fellow tribesmen failed to find the body, it became food for the wildlife.  In Eurasia and North America ravens probably consumed more human flesh than any other animal.  Ancient battlefields strewn with corpses attracted great flocks of ravens, and this species was unfairly considered an harbinger of death.  The true harbingers of death were the humans who killed each other, but superstitious people blamed the birds.

HALLOWEEN DARK CROW RAVEN FEEDING ON ZOMBIE HEAD CORPSE FIGURINE HORROR STATUE

Before the Age of Reason people thought ravens were a harbinger of doom because they saw them scavenging dead corpses on battlefields.  Of course, it was the humans who were the harbingers of doom.  People instigated the killing, then blamed the birds. This illogical thought process is typical of our species.

The raven is a bird of deep wilderness, and its range has contracted with the advance of human “civilization.”  In contrast to the raven, the crow (Corvus brachyrinchus) thrives in the vicinity of man and has increased in numbers.  Crows are more social and tolerate each other’s company, while nesting raven pairs defend their territories from other ravens.  This behavioral difference explains why nesting communal crows are better able to take advantage of concentrated anthropogenic resources such as agricultural fields and garbage dumps.  The nesting strategy of the raven makes more sense when food consists mostly of more irregularly available animal carcasses. 

Ravens are known as “wolf-birds” because they are often seen in the company of wolves, scavenging their kills.  Wolves can lose up to 45 lbs of meat per day to ravens, and some think they evolved pack behavior to help defend their kills from scavenging ravens rather than from other predators.

Ravens were more widespread in southeastern North America during the Pleistocene than they are today, though evidentally they were absent from Florida.  The only known raven nest site in present day Georgia is a cliff on Brasstown Bald Mountain, but raven fossils of Pleistocene-age have been excavated from Kingston Saltpeter Cave in Bartow County, Georgia, and Bell Cave in Colbert County, Alabama.  Before man altered the environment ravens may have been more common in the upper south than crows.  Ravens fed on the deceased individuals of Pleistocene megafauna herds.  Ravens disappeared from the midwest following the extirpation of bison in the 19th century, and likely also declined in abundance in the south following the extinction of the Pleistocene megafauna thousands of years earlier.  Ravens surely followed dire wolves around, much like they follow modern day wolf packs in the Rocky Mountains.

Jasper Wolf Kill 2012.01.13

 

 

 

 

 

 

 

 

 

 

 

Ravens are known as wolf-birds.  They hang around wolf packs for access to the meat from kills.  Wolves may have evolved pack behavior to fend off ravens.  During the Pleistocene ravens surely accompanied dire wolves.

Ravens are larger than crows growing up to 4 lbs compared to less than 1 lb for the latter.  Ravens have a 4 foot wingspan and like to soar.  Crows rarely, if ever, soar.  A large adult crow can be larger than a small juvenile raven, but there is still a distinguishing characteristic–the raven has a more rounded tail. Both are highly intelligent species with a reasoning ability that matches or maybe even exceeds that of a monkey.  And both species are omnivorous, capable of eating everything from insects, worms, birds’s eggs, and carrion to nuts, fruit, grains, garbage, and dog shit.

Common Raven - They are strong fliers and can hover like an American Kestrel or soar like a hawk.

Ravens soar with the wind, while crows generally do not. Note the rounded tail.  Crows have a square tail.

Genetic studies suggest there are  2 clades of ravens in North America.  The most common clade is the Holarctic found in Europe, Asia, Greenland, and North America.  The California clade is found only on the southern Pacific coast of North America, and this clade is more closely related to the Chihauhan raven (Corvus cryptoleucas) than to members of its own species in the Holarctic clade.  The California clade became isolated from the Holarctic clade some time during the Pleistocene.

 Reference:

Marzluff, John; and Tony Angell

In the Company of Crows and Ravens

Yale University Press 2005

Did Elk (Cervus elephus) Live in North America Prior to 15,200 BP?

October 27, 2014

A recent thorough study, combining radio-carbon dating and genetic evidence, suggests elk did not cross the Bering Landbridge and colonize North America until about 15,200 years ago.  According to this study, “there is no unequivocal fossil evidence that elk lived in North America prior to this date.”  However, not every elk fossil in North America has been radio-carbon dated, and I’ll explain later how it’s possible elk could have colonized North America before this date without contradicting the data in this study.  But first, I’ll summarize the pertinent findings of this paper which was published in The Proceedings of the Royal Society of Biological Sciences last year.

The authors of this study had difficulty even finding North American elk fossils that were thought to be older than 15,000 years.  They did find 5 but determined from tests of bone collagen that 3 had been misidentified and were either bison or horse.  The radiocarbon date on the 1 that was correctly identified as coming from a member of the deer family was 13,100 BP…within the proposed timespan.

Radio-carbon dating shows that elk have lived in northeast Asia for over 50,000 years.  (Radio-carbon dating can’t date fossils older than this.)  Scientists examined the DNA of almost 100 Pleistocene-aged and modern elk specimens from northeast Asia and North America.   They found that all living North American elk are descended from elk originating in east Asia.  North American elk apparently split from their Siberian ancestors about 15,000 years ago.

The environment of the Bering Landbridge experienced many changes over time.  It was underwater from 135,000 BP- 70,000 BP.  It rose above sea level between 70,000 BP-60,000 BP.  Between 60,000 BP-30,000 BP, sea levels fluctuated so that some times the region was inundated and at other times it re-emerged.  From 30,000 BP-11,000 BP  the landbridge re-emerged, but since the latter date, it has been submerged once again.  However, until about 16,000 BP the environment of the landbridge had little favorable elk habitat.  A relatively warmer and drier climate occurred here between 16,000 BP- 11,000 BP, and elk were able to inhabit the landbridge and colonize the rest of North America from this starting point.  Curiously, elk no longer live in Alaska because a cooler wetter climate pattern has caused their favored habitats to deteriorate here.

Archaeologists believe humans also crossed the Bering landbridge during the same time period as the elk migration, but archaeological evidence is scarce.  The presence of elk fossils in Alaska during this time period and the timing of this migration as a proxy for human migration supports their belief.  Because the climate was warmer and drier, these paleo-indians may not have been as culturally adapted to living in arctic conditions as the more recent native American inhabitants are here.

Elk in Tennessee.  This species may be a relatively recent member of North America’s fauna.  There is no unequivocal evidence of their presence on this continent until 15,200 BP.

Range map of elk.  Elk no longer occur in Alaska because habitat is not favorable there for their survival.  However, between ~16,000 BP- ~11,000 BP, climate there was relatively warmer than it is today, and elk were able to live in the region.  This is when scientists believe they crossed the Bering Landbridge and began colonizing North America. Humans without an arctic-adapted culture also crossed the Bering Landbridge during this time period.

I don’t dispute the data and conclusions of this fine study.  However, I’m not entirely convinced that elk did not occur in some regions of North America prior to 15,200 BP.  The unique environmental conditions on the Bering Landbridge between 16,000 BP-11,000 BP that allowed elk to migrate to North America probably occurred and re-occurred periodically throughout the Pleistocene.  It’s possible and even likely that elk would have crossed the landbridge during an earlier incarnation of this climate phase.  Scientists have been wrong before about the exact dating of animal migrations into North America.  Formerly, scientists assumed grizzly bears (Ursus arctos) did not colonize North America south of the Ice Sheets until about 13,000 BP when the glaciers receded.  But a few years ago, fossil evidence of a grizzly bear, dating to 21,000 BP, was found in Edmonton, Alberta.  All it would take to prove that elk lived in North America prior to 15,200 BP would be 1 specimen dating to a greater age than that.  I’m aware of 1 candidate.  There is an elk vertebrae in the Charleston Museum of Natural History that was recovered from sediments thought to be of early Pleistocene age.  It was found associated with Eremotherium, a species of ground sloth thought to have become extirpated from the region 30,000 years ago.  As far as I know, this specimen has never been radio-carbon dated.  I think it merits dating.  Would the date support the findings of the new study or would it suggest a more complicated history for Pleistocene elk in North America?

Daphne'sdorm

Photo of elk fossils found in South Carolina from the book Additions to the Pleistocene Mammal Faunas of South Carolina, North Carolina, and Georgia by Albert Sanders.  The vertebrae comes from sediments thought to pre-date 15,200 BP.

The DNA evidence from the study make it clear–all North American elk alive today descend from the elk migration across the Bering Landbridge that began about 15,000 years ago.  But this doesn’t rule out the possibility that a now extinct Pleistocene ecomorph of the elk occurred in North America prior to this date.  Both cougars and jaguars lived in North America during the Pleistocene.  DNA evidence proves the North American ecomorphs of these 2 big cats went extinct about 11,000 years ago.  (See: http://markgelbart.wordpress.com/2014/04/11/extinct-pleistocene-ecomorphs-of-the-cougar-puma-concolor-and-the-timber-wolf-canis-lupus/)  All modern individuals of these 2 species descend from populations that lived in eastern South America at the end of the Pleistocene.  It’s not unprecedented for populations of a species to become extirpated, then replaced by other populations of the same species.

Reference:

Meirav, Meiri; et. al.

“Faunal Record Identifies Bering Isthmus Conditions as Constraint to end-Pleistocene Migrations to the New World”

Proceedings of the Royal Society of Biological Sciences 281 (1776) December 2013

Dr. Arthur Gelbart R.I.P.

October 22, 2014

Circumstances force me to take an hiatus from the usual natural history topics of this blog.  Dr. Arthur Gelbart, my father, has passed away.

Arthur Gelbart was born in Buczacz, Poland on Febuary 7, 1930.  He was the son of a shoe store owner, Isadore Gelbart, and his wife Regina.  When the Nazis invaded Poland, the Gelbarts were forced to hide because the Germans were bent on eradicating all Jews.  Isadore paid an Ukranian farmer to hide his family in an hayloft for 2 years.  There, they suffered from frequent want of food and water.  Usually, they were forced to subsist on a daily piece of bread, and the water from boiled potatoes.  During summer their diet was supplemented with dandelion greens, cherries, and cucumbers.  The Gelbarts were liberated by the Russians, but  the Germans counterattacked, and the Gelbarts, along with other refugees, were trapped between the Russians and the Germans before they were able to make an harrowing escape.  My dad always loved to watch WWII movies after this experience because he enjoyed depictions of the allies killing Nazis.

My father and his mother emigrated to New York in 1947, but his parents divorced, and his father stayed behind in Germany with my dad’s brother.  My father missed 5 years of elementary school and English was his second language, yet he was one of the best students at Morris Brown High School in the Bronx, New York.  He earned a swimming scholarship to Rutgers but lost it when the coach caught him smoking cigarettes.  He then attended New York University and worked as a waiter and dance instructor in the Catskills during the summer.  He earned a Fulbright Scholarship that helped pay for him to go to medical school in Germany.  His first year of residence was in Cleveland, Ohio where he met my mother, Audrey Bailey.  They got married and left for Chicago, Illinois for his second year of residency.  I was born there in 1962.  My parents moved to Niles, Ohio shortly thereafter, and my father established a successful private practice in a small town in need of a doctor.  While living in Warren and Niles, my father witnessed the birth of 2 daughters, Susan and Elizabeth.

My father made housecalls for $5.  Today, few, if any doctors, bother making housecalls.  His services as a physician alleviated the suffering of many, and he helped save people’s lives, but in 1975 he was diagnosed with malignant melanoma and was given 6 months to live.  This prompted him to choose an easier career as a staff physician for the University of Georgia.  However, when it became evident  the deadly skin cancer was not going to be a death sentence, he got bored…about the only ailment he ever saw from the students attending UGA was VD. In 1977 he took a job teaching family practice at the Medical College of Georgia and also held the position of Medical Director of the Georgia War Veterans Nursing Home.  He held this position until he retired in 2000.

Daphne'sdorm 014

Dr. Arthur Gelbart and his granddaughter in 2005 when he was still his old cheerful self.

My father enjoyed his retirement.  He liked spending time with his grandchildren, Daphne and Justin.  He frequently went to The Family Y to run “fife miles” and take a sauna and a steam, and in the evenings he liked to watch the same movies and Seinfeld reruns over and over.  In 2008 his health began to slowly decline due to numerous problems.  He died on October 22, 2014. 

I will miss him.

Crocodylians Eat Fruit but may not Disperse the Seeds

October 17, 2014

Scientists know some species of mammals, birds, turtles, and lizards eat fruit and disperse the still viable seeds across the landscape in their scat.  Surprisingly, 13 of the 18 species of crocodylians in the world are known to actively seek and eat fruit also, yet until recently scientists didn’t know whether the seeds they defecated were still viable or not.  Adam Rosenblatt, formerly of Florida International but currently on the Yale faculty, led the first ever study of fruit seed viability in crocodylian crap.  He analyzed the contents of 54 American alligator stomachs from specimens living in the Everglades.  He found fruit seeds in 12 of them.  His alligators ate the fruit of red mangrove, coco plum, and pond apple, but the latter, a type of pawpaw, was by far the most common fruit found in alligator stomachs.  One specimen had 1286 pond apple seeds in its stomach.  Each pond apple has about 6 seeds, so that means this particular alligator ate at least 200 pond apples.

The scientists planted 20 pond apple seeds recovered from alligator stomachs, resulting in a 0% germination rate vs. a 75% germination rate for pond apple seeds that did not go through an alligator’s digestive system.    Alligators often scavenge well-rotted carcasses infected with toxic bacteria, but their strong digestive acids destroy the toxins.  Dr. Rosenblatt belives these strong digestive acids also destroy the viability of pond apple seeds.  Moreover, alligators have a slow metabolic rate, and the seeds can stay in an alligator’s digestive system for months.  Pond apples germinate rapidly and lose viability if not exposed to soil within a short period of time.  Dr. Rosenblatt doesn’t know if the same holds true for other species of fruit and other species of crocodylians, but it appears that American alligators do not help disperse pond apples.

gator fig. 2

Alligator actively seeking out kumquats.

Pond apple (Anona glabra).  Scientists planted pond apple seeds they recovered from alligator stomachs.  None of them germinated compared to the average 75% germination rate of non-digested pond apple seeds.

Pond apples have been introduced to Australia where they have become an invasive species.  Apparently, the native cassowary and feral pigs are facilitating the spread of this species on that continent.  Cassowaries and hogs have quicker digestive systems and weaker stomach acids than those of alligators, and pond apple seeds are capable of surviving the journey through the alimentary canals of these 2 species.  Pond apple seeds are frequently found sprouting in the fresh cassowary and hog dung.

Cassowary and young.  The seeds from pond apples eaten by cassowaries are viable, and this bird is helping spread this invasive species in Australia.

Reference

Rosenblatt, Adam; and Scotty Zara, Michael Heithore, and Frank Mazzetti

“Are Seeds Carried by Crocodylians Viable? A Test of Crocodilian Suochory Hypothesis”

Southeastern Naturalist 13 (3) 2014


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