Posts Tagged ‘Gopher tortoise’

Gopher Tortoises (Gopherus polyphemus) on Anastasia Island State Park

May 27, 2016

Access to swimming beaches near St. Augustine, Florida is not free, but for only $8 per car, vacationers can enjoy a day at the beach on Anastasia Island State Park.  My daughter and I wandered into the surf there one morning in mid-May (last week as I write this).  We experienced strong currents, sudden deep drop-offs, quicksand, and no lifeguard on duty.

Several boardwalks stretch over protected beach dunes, presenting a view of the part of the island known as “Bird Island. ” I saw some birds but not many…I saw more birds in downtown St. Augustine.  I saw a flock of 12 brown pelicans, a great egret, a red-winged blackbird, cardinals, mourning doves, and city pigeons.    But many of the birds I saw in St. Augustine probably nest in the dunes on Anastasia Island.  I’m sure the ring-billed and laughing gulls and the least turn that I saw on St. Augustine nest here.

We took a stroll around the parking lot, and I was excited to find 2 rare gopher tortoises, a living relative of 2 larger extinct species of Pleistocene tortoises.

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This gopher tortoise was walking by the side of the parking lot in Anastasia Island State Park.

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I saw this smaller gopher tortoise first.  Although I’ve seen gopher tortoise burrows, this was the first time I’d ever seen the actual tortoises.

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Anastasia Beach was not crowded mid-morning in mid May.

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Part of Anastasia Island is known as Bird Island.  The currents are depositing sand on the north end and building it up.  Gulls and terns are probably nesting in these beach dunes.  I saw an adult least tern across the bay in St. Augustine.  It may have hatched on this island.  Sea oats, sea grape, and cactus hold down the dunes.

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A brackish marsh.

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Red-winged blackbird.

The giant southern white butterfly (Ascia monaste) is abundant on Anastasia Island in May.  Larva of this species feed on saltwort and plants from the mustard and cabbage family.

I was too lazy to chase around butterflies , so I ripped off this photo from google images. Giant southern white butterflies were abundant on Anastasia Island.

A brackish lagoon bisects the island and wading birds hunt for fish and shrimp in it.  This state park consists of a variety of habitats–surf, beach dune, brackish marshes, and a kind of stunted maritime forest where live oak, myrtle, bayberry, and cedar grow.  The Ponce de Leon Fountain of Youth Archaeological Park in St. Augustine is in the middle of a more mature maritime forest, and there is a boardwalk over a salt marsh within this park.  I enjoyed excellent birdwatching here and saw great blue heron, great egret, least tern, eastern kingbird, red-breasted merganser, and a white ibis.

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A fish taco at Joe’s Grill on Anastasia Island.  This was the best thing I ate on my vacation.  It’s a soft taco wrapped around a crunchy taco with well seasoned fish, lettuce, cheese, a delicious salsa, and a sauce.  And it only cost $5.25.  Most of the entrees offered on the tourist trap restaurants in St. Augustine cost $28-$40 during supper hours.

St. Augustine is a Tourist Trap

We stayed in the Best Western Bayfront Inn in St. Augustine.  They charged an additional $10 per night for a “self-parking fee.”  Most of the tourist trap restaurants and museums are not handicapped accessible, although Anastasia State Park, administered by the state, does offer free beach wheelchairs.  The restaurants in St. Augustine charge kiss-my-ass prices.  Lunch menus offer the same items for almost half the obscene suppertime prices.  I suggest vacationers stay in the cheaper less crowded hotels on Anastasia Island.  From there it’s a short walk across the drawbridge to the best attractions of St. Augustine–the Castillo de San Marcos and the Ponce de Leon Fountain of Youth Archaeological Park.  The Alligator Farm and Zoological Park is located on Anastasia Island.  I would have liked to have visited this attraction.  They keep every species of crocodilian in the world.  However, my daughter chose the Fountain of Youth and it was cheaper anyway.

 

 

Extralimital Species of Pleistocene-aged Turtle Remains Found in the Upper Coastal Plain of Alabama

August 21, 2015

George Phillips wrote his Masters Thesis about Pleistocene-aged, non-mammalian, vertebrate remains found in creeks that flow through the Alabama and Mississippi upper coastal plain, a region also known as the Black Prairie.  Turtle shells are by far the most abundant remains found here because of preservational bias.  Turtle shells are very durable, helping protect the reptile while they are alive.  This durability also makes turtle shells more likely to survive the ravages of time when the bones of most other vertebrates disintegrate.  The results of his study show that several species of turtles have experienced interesting range redistributions since the end of the Ice Age.

Map of Alabama highlighting Dallas County

Dallas County, Alabama.  Bogue Chitto Creek, located in this county, yields many Pleistocene fossil remains.

Blanding’s turtle (Emboidia blandingii) is an endangered species presently restricted to the upper Midwest and parts of New England.  Most of this species’ present day range was under glacial ice during the Ice Age and thus uninhabitable.  Remains of Blanding’s turtle can be found in Pleistocene deposits as far south as the Black Prairie region in Alabama.  The presence of this species in Alabama suggests much cooler summers in the south during the Ice Age (though winters may have been as mild or just a little cooler than those of today). Blanding’s turtles may be unable to endure the long hot summers of the present day south, and this may be the limiting factor on their range today.

Blanding’s Turtle occurred in Alabama during the Ice Age but no longer ranges this far south.

Map of Blanding's Turtle

Present day range of Blanding’s turtle.  During the Ice Age about 70% of this territory was under glacial ice.

The wood turtle (Glyptemys insculpta) is another species of turtle with northern affinities that lived in Alabama (and other parts of the south) during the Ice Age.  This species may also be unable to survive long hot summers.

Plastron of an adult male.

Wood turtle.

Present day range map of the wood turtle.  During the Ice Age >90% of this range was under glacial ice and this species retreated south.  Longer hotter summers chased them back up north.

The only known Pleistocene-aged specimen of a musk turtle (Sternotherus carianitus) was found in Catalpa Creek, Alabama. Today, this species occurs to the west of this site.  Its rarity in the fossil record is unexplained and is probably just due to chance.  During the Pleistocene it apparently ranged further east than it does today.  Any number of unknown reasons could explain its extirpation from the most eastern parts of its range–disease, excessive egg predation, or competition with other species of turtles.

File:Carapace Sternotherus carinatus.JPG

Musk turtle.

Present day range map for musk turtle.  They formerly ranged a little further east during the Pleistocene.

There are 3 species of red-bellied turtles.  The Florida red-bellied turtle (Pseudemys concinna) is presently restricted to peninsular Florida, but Pleistocene-aged remains of this species have been found in Bartow County located in north Georgia.  The Alabama red bellied turtle (Pseudemys alabamensis) is presently restricted to extreme southern Alabama and Mississippi.  The red bellied turtle (P. rubriventris) is presently restricted to the mid-Atlantic states, but Pleistocene -aged remains of this species have been found in the upper coastal plain of Alabama.  It’s likely these 3 species of red-bellied turtles diverged from 1 continuous population that existed before the Pleistocene-Holocene transition when for some unknown reason they became geographically isolated into their present day ranges.  Their curious range distributions beg for a study of their molecular DNA.  The 3 present day species represent a speciation event that may have occurred as recently as 10,000 years ago.  I can’t determine why red-bellied turtles were extirpated from regions in between their present day ranges.  Did overharvesting by humans play a role?

Present day range map for the mid-Atlantic red-bellied turtle (Pseudemys rubriventris)  Remains of this species have been identified from Alabama.

Range map for Alabama red-bellied turtle.  The Pleistocene/Holocene transition was likely a speciation event that caused the 3 species of red-bellied turtles to diverge.

An extinct Pleistocene subspecies of box turtle (Terapene Carolina putnami) was common in Alabama’s coastal plain.  It was larger than present day box turtles but otherwise was similar.  There is no direct evidence of gopher tortoises (Gopherus polyphemus) from the Black Prairie region during the Pleistocene, but a Pleistocene-aged specimen of an indigo snake was found in Bogue Chitto Creek located about 40 miles north of the present day range of this tortoise.  Indigo snakes depend upon gopher tortoise burrows for shelter, so the presence of this snake suggests the presence of gopher tortoises nearby.  Gopher tortoises require sandy soils for burrowing.  They don’t burrow in the heavy upland clay soils so widespread in this region, but they may have burrowed in the alluvial (streamside) sands by the creek.  Gopher tortoises require open environments where they can feed upon short sun-loving plants.  The closure of the forest canopy would have caused their extirpation here.

Two scutes of the extinct giant tortoise (Hesperotestudo crassicutata) were found in this region.  Scientists puzzle over the co-existence here of the cold adapted wood turtle and Blanding’s turtle with the giant tortoise, a species they assume required a frost free environment.  I disagree with their assumption.  I hypothesize giant tortoises were capable of surviving freezing temperatures by either burrowing underground, like their closest living relative (the gopher tortoise), or by utilizing burrows dug by giant ground sloths. If giant tortoises could survive mild frosts as I believe, this species could have co-existed in the same region as cold-adapted species of turtles.  However, it’s just as likely their remains represent a warm climate phase, temporally distinct from when wood turtles and Blanding’s turtles roamed the creek bottoms.  As far as I know, none of these specimens has been radio-carbon dated.

Species of turtle remains found in Pleistocene deposits here that still occur in the region include snapping turtle, alligator snapping turtle, spiny softshell, stinkpot, painted, slider, and Alabama map turtles.

Reference:

Phillips, George

“Paleofaunistics of Non-mammalian Vertebrates from the Late Pleistocene of the Mississippi Black Prairie”

North Carolina State Masters Thesis 2006

Southeastern Grasslands are of Great Antiquity

May 29, 2014

I enjoy watching a summer thunderstorm.  Lightning strikes offer a natural fireworks show that sometimes surpasses the manmade kind.  The furious wind and roaring thunder show the excited side of mother nature.  It’s the dangerous side of nature–a human could be vacuumed into the sky by a tornado, electrocuted by lightning, or clobbered by a hailstone or wind-strewn debris.  Nobody, not a king nor a baby, is immune to these hazards.

Natural fireworks.

Some anthropologists and a few old school ecologists wrongly believe most of the grasslands that occurred in southeastern North America when Columbus accidentally sailed into the Caribbean were the result of manmade fires.  Reed Noss dispels this notion in his book, Forgotten Grasslands of the South. The map below shows the frequency of lightning strikes in North America.  The south, and especially Florida, has more lightning strikes than any other region of the continent.  Dr. Noss believes the high frequency of lightning strikes can spark enough wild fires to maintain abundant grasslands without any human activity.

Map of average annual lighting strikes in North America between 1989-1999.  Lighting strikes were naturally common enough to have sparked grassland-creating wild fires long before humans arrived in North America.

Long Distance Controlled Burn

A longleaf pine savannah on fire.  Longleaf pines are one of the few species of tree whose seedlings can survive fire.

Several lines of evidence support Dr. Noss’s conclusion that anthropogenic activity was not necessary to maintain grasslands.  Formerly, longleaf pine savannah covered most of the coastal plain region of the south.  There were even patches of pine savannah in the piedmont region, though oak and hickory dominated that area.  There are over 900 species of plants endemic (meaning they live nowhere else) to longleaf pine savannah compared to just 80 endemic species found on the grasslands of the Great Plains.  A high number of endemic species suggests an ecosystem of great antiquity and stability.  Because evolution is usually a slow process, it’s not likely that all of these endemic fire-dependent species could have evolved in just the last 12,000 years.  Longleaf pines require fire intervals of 1-10 years or hardwoods will crowd them out.  Longleaf pines grow slowly, taking decades to reach reproductive age.  A species that reproduces this slowly would have never been able to adapt quickly enough to survive a sudden change in fire regime caused by man.  These fire dependent species must have already been present before man colonized the region.

Many species of animals are also endemic to pine savannahs.  The gopher tortoise and the red cockaded woodpecker are perhaps the 2 most well known vertebrates dependent on this fire-influenced environment. Gopher tortoise fossils have been found that date to millions of years ago, while red cockaded woodpecker fossils come from deposits in the vicinity of 200,000 years old.  The presence of these species and many others in the fossil record long predate man’s entrance into the region.  This is obvious evidence that southern grasslands preceded man.

There was a lower frequency of lightning strikes during the coldest stages of the Ice Ages.  Evidence from most fossil sedimentary sites show little, if any charcoal, indicating reduced fire activity.  However, less precipitation combined with megafaunal grazing created grasslands during the colder climatic phases.  Following the megafaunal extinctions, fire activity spiked because so much vegetation was no longer being eaten and instead it became dry tinder.

During the Last Glacial Maximum, longleaf pine savannahs still occurred in refugium located in Florida, Louisiana, Texas, and probably along the continental shelf where sea levels regressed.  Paradoxically, these areas were warmer and wetter during Ice Ages because the Gulf Stream shut down and warm water that normally circulated north pooled around these lower latitudes.  Oak scrub and prairie, the result of aridity and megafauna foraging, predominated in the upper coastal plain.  Longleaf pine savannah didn’t recolonize the upper coastal plain until about 6,000 years ago, but the pollen record suggests this type of environment has waxed and waned cyclically for millions of years, becoming common and widespread during warm and wet climatic phases.

The Moody Forest Natural Area

April 6, 2012

Between Reconstruction and World War II, lumber companies raped Georgia, clearcutting the beautiful forests that hadn’t already been cleared by greedy, slave-owning cotton farmers.  Jake Moody refused to let them destroy his beloved property, known locally as Moody Swamp.  He made his heirs promise not to allow its destruction.  In 1999 the descendents of his heirs sold 4500 acres to The Nature Conservancy, and today that organization shares ownership and management duties with the Georgia state government.  Thanks to Jake Moody’s foresight and love of nature, a remnant of old growth forest still exists here.

The Moody Forest Natural Area is located in Appling County, Georgia about a 10 minute drive north of Baxley and about a 10 minute drive south of the Hatch Nuclear Plant.  It can be accessed via East River Road, a well-maintained dirt road off Highway 1.  The dirt road is a smooth ride with very few bumpy rutted areas.  Despite being in the middle of nowhere, there are many nice houses on the opposite side of the road from the nature preserve.  The people living here must really enjoy country living–I saw not a single house for sale.  A fat old dog sleeps in just about every resident’s front yard, and many people keep cows, horses, and/or chickens.  One person even had an apiary.  I rank East River Road as one of the best places in Georgia for a naturalist to live.

Big slash pine.  Note the burned trunk.  The Moody Forest Natural Area is burned on a regular schedule to improve habitat for wildlife.  Mature pines and oaks usually survive light ground fires.

A swamp chestnut oak next to an old dwelling of some sort.  There’s space under the shack for chickens and a covered place to hitch the mule up to.  The oak is bigger than the slash pine in the above photo but a size comparison with a person wasn’t possible–by this time on our hike, the mosquitoes had chased my hiking partner into the car.  There are reportedly 200 year old post oaks and overcup oaks in the preserve.  Although dominated by pine, there are a surprising number of oaks here including swamp chestnut, post, Shumards or black (I can’t tell the difference between those species), southern red, overcup, and laurel.

There are 5 miles of trails in the preserve besides the access road that is adjacent to the Moody Family cemetery. Tavia’s Loop Trail is 3 miles long, and the River Trail is 2 miles long but because it’s not a loop that means it’s a 4 mile hike back and forth. If I was by myself, I would have hiked both, but there are no restrooms located anywhere near the preserve, and my wife needed one.  Spending money on a public lavatory probably isn’t a high priority for The Nature Conservancy.  I get the impression The Nature Conservancy doesn’t really want people to tour their protected sites.  The least they could do would be to build an old fashioned rustic outhouse.

Open pine parkland woods.  I didn’t see a single longleaf pine.  Instead,  I saw  loblolly and slash pines.

350 acres of longleaf pine-wiregrass savannah occurs at Moody, but I didn’t see any.  I hiked 1/2 mile up an access road and then another mile on Tavia’s trail, and I didn’t seen a single longleaf pine tree.  There was barely any wiregrass.  At the time of European colonization, longleaf pine savannah was the dominant landscape on the southeastern coastal plain.  Even in the protected Moody Preserve it takes up less than 10% of the land area, showing just how rare it is now.  Perhaps, if I had the opportunity to complete the whole loop trail, I would have come across it.  Instead, I saw mostly open pine parkland dominated by loblolly pine, slash pine, and post oaks.

Information I’ve read about Moody Forest makes no mention of ferns.  This type of fern is by far the most common plant in the undergrowth here. I think it’s royal fern, but I’m not sure.  It’s worthwhile  to see nature in person rather than just reading about it.

Here’s some wiregrass sprouting up after a recent burn.  The only people we encountered were a couple of workers with firestarting equipment.  By setting fires, they are mimicking Indian land management techniques .  Of course, before the Indians,  fires were more irregular and less frequent.  Pleistocene fires may have some times been devastating.  However, more often than not, Ice Age fires were  less severe because the megafauna consumed so much plant material there was less fuel, and dry climate phases fostered less plant growth.

A burrow dug by an endangered gopher tortoise.  I didn’t see the tortoise but I did see 2 rabbits just above the burrow.  I suspect they use the burrow for shelter.  I also saw a red-shouldered hawk carrying a cotton rat, turkey and black vultures, some gray squirrels, pileated woodpeckers, a red-bellied woodpecker, deer tracks, and lots and lots of mosquitoes and gnats.

A place to hitch up the ole mule.  The preserve needs an old-fashioned but working outhouse.  Women don’t like to squat in the wilderness.

This former homesite has 2 fireplaces.  This is one of them.  There are plenty of old ruins at Moody making it doubly interesting to explore.

The Moody Natural Area offers much to explore for the naturalist and the historian.  I barely scratched the surface during the brief but treasured time I was there.  I didn’t even have time to see any part of the River Trail.  Reportedly, 600 year old cypress trees stand there.

This cow pasture sits on the corner of Highway 1 and East River Road.  It’s the only really open space I saw in the vicinity of Moody Forest.  I pretended the cows were long-horned bison and imagined being in the Pleistocene.  There were Canadian geese by the creek, but I don’t think they’re visible in the photo.

Altamaha River Roadside Park

I didn’t have an opportunity to hike the River Trail in Moody Forest, but I wanted to see the Altamaha River up close.  The intersection off Highway 1 and the river has a Roadside Park that I investigated instead.

Graffiti on the Highway 1 Bridge that spans the Altamaha.  I love graffiti.

Spanish moss-draped post oaks.  This is an unusual combination of species.  Post oaks grow on dry upland sites; Spanish moss prefers warm moist lowland sites.  However at this site, they co-occur and dominate.

This is how I imagine a common Pleistocene landscape in Georgia might appear, but with taller grass and populated with bison and horses.

The Altamaha River.  This bend of the river almost looks like a lake.

A scary steep bluff.  Almost looked like a cliff from here.

Here’s proof that a kind of grape other than muscadine grows in south Georgia.  I think this is a River Grape which produces small blue fruit.

Fire Suppression = A Decline in Biodiversity (Part 2–The Animals of Longleaf Pine Savannahs)

June 29, 2011

Fox Squirrels come in several color phases–orange, black, and gray.  Some have white or gray masks as well.

Fox Squirrel–Sciurus niger

I love these big colorful squirrels.  I lived in Niles, Ohio until 1975, and our home was bordered by oak woods on 2 sides.  Big orange fox squirrels were the playful denizens there.  But since I’ve lived in Georgia, I’ve only seen one–a black masked fox squirrel foraging with a group of gray squirrels (Sciurus carolinensis) in a pecan orchard in Burke County.

This range map is bullshit.  No statewide survey of fox squirrels has been done in at least 50 years, if ever.  It’s likely an accurate range map would show a much patchier distribution.

Southern fox squirrels differ in their habitat requirements from northern fox squirrels, despite being the same species.  The former prefer mature longleaf pine savannahs with fingers of oak forests, while the latter thrive in oak/hickory woods.  Fox squirrels are declining in Georgia because longleaf pine savannahs were largely replaced with shorter rotation loblolly pine tree farms.  Lumber companies harvest loblolly pines every 50 years which is not enough time for trees to develop snags.  The Trees are also planted closely and fire is suppressed.  Gray squirrels are more abundant today in state because they’re well adapted to the dense young forests that have sprouted on abandoned agricultural lands.  Gray squirrels escape predation by jumping from tree top to tree top, while fox squirrels prefer to dash on the ground as far as they can before retreating to a tree.  Though clumsy in trees compared to their smaller cousins, their larger size allows them to put up more of a fight, if a predator catches up to them.  This difference in behavior explains why gray squirrels occur in closed canopy forests, and fox squirrels prefer open parkland forests.  For this reason I think fox squirrels were more abundant in this region during the Pleistocene when open environments were common.  Areas managed for red-cockaded woodpeckers should benefit fox squirrels.  Forest managers used longer rotations and fire to maintain the bird’s required habitat.

Red Cockaded Woodpecker–(Picoides borealis)

Photo of a red cockaded woodpecker from google images.  All the photos in this entry are borrowed from there.

Thirty years ago, this bird was on the verge of extinction, despite having formerly been common throughout the south.  Fire suppression and short forest management rotation nearly caused the death of this species.  Young pine trees never develop the soft rot that red cockaded woodpeckers need for boring nesting cavities.  As a defense mechanism, red cockaded woodpeckers constantly peck wells below their nesting cavities from which pine sap continously flows.  The pine resin repels rat snakes–their number one predator.  For this defense mechanism to work, live trees are a must.  And without fire hardwood understory reaches the level of the nesting cavity allowing flying squirrels, and other predators easy access.  Flying squirrels will decimate red cockaded woodpecker nests.

In a successful effort to save the birds, scientists identified habitat requirements and some suitable land was set aside and managed using prescribed burns and longer tree harvest rotations.  Birds were relocated to the best habitat, artificial nesting boxes were installed to supplement the shortage of good nesting trees, and flying squirrel exclusion devices were used.  In many protected areas red cockaded woodpecker family groups (family groups consist of 2-10 individuals) have increased dramatically to the point where it’s no longer necessary to provide artificial nests or to protect them from flying squirrels.  At SRS for example the population grew from 1 family group in 1987 to 30 by 2003.

Sandhill Crane–(Grus canadensis)

These impressive birds grow to 5 feet tall.  They prefer to nest in grassy marshes adjacent to prairies or savannahs.  The real life version of Sesame Street’s Big Bird used to be common, but since grasslands and wetlands have declined so have the birds.  Georgia’s population includes a permanent one consisting of small family groups, and large congregations of winter migrants.  They’re omnivorous feeding on insects, crayfish, mice, snakes, frogs, worms, acorns, fruit, roots, and farmer’s crops.

Bachman’s Sparrow–(Peucaea aestivalis)

Another inhabitant of open pine savannahs that is declining in abundance.  I heard this bird’s song on a youtube video and recognized it as one I’ve heard.  Evidentally, the sparrow still occurs in Augusta.

Indigo Snake–(Drymarchon corais)

This snake grows to 9 feet long, making it the longest serpent in North America.  They’re rare because their habitat has been fragmented, and they need large ranges.  They hunt during the day and retreat into gopher tortoise burrows at night.  A wide variety of prey is taken–other snakes including venemous ones, small mammals, birds, frogs, and fish.  Indigo snakes don’t kill by constriction or envenomation, but instead bite the head of their prey and thrash, breaking the spines of the small creatures.  Their metabolism is faster then that of most other snakes.

Gopher Tortoise–(Gopherus polyphenus)

 

Gopher tortoises depend on a frequent fire regime to spark the growth of the kinds of plant they eat.  They also like sandy soil that makes it easy for them to dig their elaborate tunnel systems.  They’re a keystone species–over 60 vertebrates and invertebrates depend on their burrows for shelter.  (See also my article–“The Giant Extinct Tortoise, Hesperotestudo crassicutata, must have been able to survive light frosts” from my April or March archives)

Popular game animals such as white tail deer, turkey, and quail thrive in longleaf pine savannahs.  Savannahs were a favored habitat of many extinct Pleistocene species as well including mammoth, long horned bison, horses, llamas, Harlan’s ground sloth, hog nosed skunks, giant tortoises, and others.