Tuesday, January 4, 2011

More on Okefenokee Critters ...

Reportedly, there are more than 200 different species of birds, 60 species of amphibians, 34 different species of fish, 40 species of mammals and 50 species of reptiles who call the Okefenokee home. I think I may have encountered 30 of them in my two days there. So here I will briefly look at some of the animals I saw and a few that I didn't but wished I would have!

Animals I saw.

American Alligator: Gotta start with this one! This famous resident of the swamp came off the endangered species list in 1987 as there were gazillions of them out there! Of course, southeast Georgia has suffered from a severe drought for the past year and a half so the water level in the swamp was really low. When this happens all the alligators become concentrated in the remaining pockets of water. I suspect I encountered more than one normally would. From this, we can guess that there are a lot of other critters roaming around the swamp as alligators are apex predators, top of the heap, king of the hill -- ain't nothin' gonna eat an alligator ... except people. Hey, they have even been know to eat black bears! (And a few too curious people) To support so many large predators this high up the food web, there have got to be lots of little creatures, providing lots of energy that they, in turn, gathered from lots of plants.

Like all reptiles, alligators lay hard shelled eggs, though in this case, rather large hard-shelled eggs. The eggs are laid in a nest of rotting vegetation the female builds near the water. The rotting vegetation keeps the eggs warm, as the female does not hang around. As in other reptiles the temperature of the egg will determine the gender of the baby alligator; temperatures in teh low 90's (F) will produce males while temperatures in the low 80's (F) will produce females. Pretty cool, huh. (Our Diamondback Terrapin eggs are the same!)

(For still more on the American Alligator, see the post on Harris Neck NWR: http://kurtswinterwetlands.blogspot.com/2010/12/harris-neck-nwr-georgia.html)

My escort...
Great Blue Heron: We know this bird locally as the Johnnie Crane. A common year-round resident in the Chesapeake it is equally common in the Okefenokee. Standing about 4 feet high the Great Blue Heron waits patiently in the shallows for an unsuspecting fish to swim by. Snatching the fish with a quick snap of its long beak, the heron deftly gives it a flip and swallows it whole. I wonder how they keep alligators from doing the same thing to them? As I canoed I was escorted by a couple of herons who kept flying ahead of me, landing, then flying away again when I caught up to them. Along the way there were tons of alligators, but I suppose the herons know well how to avoid them, and truly the alligators seemed too lazy to care. Alas.

Belted Kingfisher: Another common bird of the Chesapeake also preceded me as I canoed along. Clacking as it went, and never going too far ahead of the canoe before landing it led me for about 4 miles down the canoe trail.


Killdeer
River Otter: I only saw one kind of mammal and only saw it once; as I paddled silently along I came upon an otter resting on a log under the branches along the edge of the water. As I reached to turn on my camera, it looked up and silently slipped off the log and into the water. I followed the bubbles it left behind but did not see mim again. This was a cool encounter as we both seemed to see each other at the same time, regarded each other with mutual curiosity and then both went on our way. What was really cool is he was only about 5 feet from me!

Basking Cooter


Green Heron
Red-Bellied Turtle















Monday, January 3, 2011

Monday ... the Last Day's Drive



Ok, so this was utterly uneventful -- a straightforward 3.5 hour drive from Roanoke Rapids, NC to Hollywood MD where I was reunited with my cat. (At least some creature was happy to see me return!) I will post a couple of things today and try to finish the Okefenokee Swamp posts on Tuesday. Wednesday, the 5th of January, I will wrap up with some bits and bobs.

The Welcoming Committee

Okefenokee Peat ... Swamp or Bog?

Exposed Peat due to drought.

Hooded Pitcher Plant
Insects beware!
I'm not sure if I mentioned it before, but the Okefenokee swamp is not really a swamp ... though it has swamps within it. It is really a wildly diverse collection of habitats -- all variations on the peat bog. It might, in fact, be better described as a bog rather than a swamp. To the west, in the upland area there are more true swamps and less of what we normally think of as a bog. The Eastern half is very bog like. Bogs are depressions filled with peat -- usually moss or lichen and very acidic water. They tend to be fragile and diverse habitats. It is here, for example that you will find carnivorous plants as the soil is rather nutrient deficient. The peat, or collected dead plant material, has been accumulating in the Okefenokee basin for thousands of years.





Exposed peat
with a thin layer of dried muck
So why doesn't peat decay and turn to muck like we find with the plant material that accumulates in the bottom of our tidal marshes here in St. Mary's County? Well, first and obviously, peat accumulates because more organic matter is deposited than rots and so there is a net increase in organic stuff. So lets take a step back and remind ourselves of what is responsible for degrading organic stuff -- mostly bacteria (and some fungus); oxygen loving bacteria. Now here around the Chesapeake we are familiar with the problem of having too much oxygen consuming bacteria breaking down organic stuff as this is, after the excessive input of nutrient pollutants, what causes the depletion of oxygen in the water and the annual, and ever growing, summer dead-zone at the bottom of the Bay. Returning to our peat bog, we can imagine that all that plant material is a feast for the bacteria! But while feasting the bacteria consume all the oxygen, which kills the bacteria! So the available oxygen limits the amount of bacteria and the bacteria themselves limit the available oxygen! Needless to say there is not a lot of oxygen in the water of a peat bog! And, of course, the deeper you go the less oxygen there will be! (Oxygen comes from air, inputs of water and living submerged plants -- from the top!) We should note that the acidity of the water also inhibits decay, and the acidity of the water will increase the deeper we delve into the peat layer. Whew.


Peat with muck layer peeled back
So why is our marsh any different? Well, perhaps the big factor is the amount of water that enters the system. The Okefenokee is entirely rain fed so there is not a great deal of oxygen being added by incoming water. Our marshes have creeks at the back of them, bringing in fresh oxygen, and they may be subject to the tide which also increases oxygen levels. For whatever reason, the amount of dead organic material entering the marsh does not overwhelm the bacteria's ability to break it down. There is no known exact formula for why some places accumulate dead plant material and others do not.


Peat dug up a bit
So what then, exactly is peat? From the description above we can see that some areas where dead plant material is deposited do not decay rapidly, but they do decay! At least partially, until they are buried so deep that decomposition stops. While the plant material is near the surface the weaker parts of the plant (like cellulose) break down, but there is not enough time for the tougher, more resilient parts of the plant to decompose before the oxygen runs out, the acid levels build up and decay stops. So all that remains of the plant, and what accumulates over time, are the lignins or the strong structural stuff that fill the gaps in cell walls. It is what makes trees stand upright! This process of partial decay is called, not surprisingly, or creatively, "peatification".

Closeup of peat fibers ... partially decomposed plant material.



Geology of a Swamp ...

Once upon a time, the Miocene Era (23 to 5 million years ago) to be specific, a layer of clay was laid on the ground during a time when the climate was warmer. It is this layer of clay, called the Hawthorne Formation, that has made the ground impermeable – bucket like, the reason why water in the swamp doesn’t just disappear into the ground. The Hawthorne Formation is a name for layers of coastal sedimentary rock that have similar features.  Later, during the Pliocene era ( 5 to 2.5 million years ago) as ocean levels rose and fell, remnants of barrier islands and coastal bays were left behind. The Okefenokee basin is an archaic coastal bay, defined on the eastern side by an equally archaic barrier island which acts like a dam and holds the rainwater in place. The modern wetland itself began to form during the late Holocene (12,000 years ago to the present) when the climate warmed and plant-life once again began to thrive.

Uplands to the West, ridge to the East
So you can look at it this way: Imagine a clay bowl that was flooded by rising sea levels where barrier islands (like Assateague Island, where Ocean City, MD is located) were established with coastal bays behind them – just like in modern times. As the climate cooled and the sea levels dropped a series of ridges with basins behind them were left behind.  So the eastern edge of the Okefenokee Swamp is defined by an old barrier island, called Trail Ridge, and to the west of this ridge is the basin, now filled with rainwater and called the Okefenokee Swamp.  You can imagine how the swamp has grown over time as sediments began to fill the basin, displacing and raising the water level. The water would over flow and spread out over an even greater area! So today we can find on the eastern part of the swamp the oldest, deepest part of the basin where the open water wet prairies and floating islands of accumulated peat are located and as we move west and upland we find flooded forests. (Flooded later as the basin filled with sediment and the water level rose!)

It can be hard to imagine our Earth as a constantly changing little blue ball. The change is slow, imperceptible in our lifetimes – with the possible exception of global climate change – but is taking place none the less. It is a perpetually unfolding story that we are only beginning to understand.

Sunday's Drive ...

I left really early Sunday morning, heading for roanoke Rapids, NC. It was basically a pretty boring day of 8 hours diving, stopping only at rest areas along I95. I planed to get to the motel relatively early so I could write and post more Okefenokee bits. The driving and arriving worked out OK but internet at the motel was down so I couldn't post or research anything...not that I was complaining about having an evening off!

Saturday, January 1, 2011

Canoeing with Alligators

To hear my sister talk, canoeing with alligators is an act of sheer folly. One might as well have dinner with a group of flesh eating zombies, such are one's chances of survival. So here are the possible alligator responses to an approaching canoe in order of liklihood:


Well hidden!




1) Alligator does nothing, looks at you but you don't even see it!








Alligator does nothing ..





2) You see it, it sees you, and the alligator still does nothing.









This fellow will just slowly sink ...






3) The alligator is in the water and slowly sinks, regardless of whether you see it or not.







Slippin' in backwards





4) The alligator is out of the water, gets spooked and dives or slips in -- you will know.










5) The alligator sits up, supported by his long tail and hind legs, and begins to recite Shakespearean sonnets in a remarkably well refined BBC accent. (Look for DVD in stores.)








6) The alligator launches toward the boat, knocks it from below, capsizing the boat, and promptly begins to devour the unwary paddler(s). (Image not available: too gruesome.)




Catching some rays
Now, having said this there were some interesting moments. Imagine, if you will, paddling down a shallow, narrow slough -- maybe 6' wide and 2' deep -- and about 10 meters in front of you an alligator the size of your canoe and weighing 10x more than you dives into the water. Now this poses a rather interesting dilemma. What do you do? Continue on, knowing you will have to paddle right over this beast's back? Or maybe you wait for the alligator to ... to do what? Leave? Ha! What are the odds of that! You could, then, just turn around and find another way forward. My choice ... paddle on! ... with trepidation. Nine out of ten times I passed never knowing what happened to the alligator, but also knowing he was not far away! Occasionally, I would bump the alligators back, much to his/her annoyance but also with no lasting discomfort to either the alligator or myself.

They sometimes hang out in groups
Another interesting phenomena, though possibly a figment of my overactive imagination, is when an alligator sees you coming, slips or dives off the shore and swims directly toward you, submerging along the way; 10 seconds later you feel something hit your canoe from below. Now, I swear, this happened a lot! Of course, it is a swamp and there are sticks and logs and a million other things that might strike the bottom of a canoe -- so perhaps it is just a coincidence that 10 seconds after the alligator starts swimming toward you the bump from below is felt. Hmm ... I think not! (At least it makes for a better story ...)

Except for the occasional heart stopping moment when you startle one alligator who leaps into the water with a huge splash, thus startling the other EIGHT alligators that are sleeping nearby and they ALL then leap into the water and all NINE of them start swimming toward your boat, canoeing with alligators is pretty uneventful.

The old girl feeling right at home ...
So it would seem that canoeing alongside alligators is no different than encountering any wild animal -- they all can bite, they all can be dangerous, they all deserve respect and simply put the old axiom remains true, especially with alligators: "Leave them alone, and they will leave you alone."






Alligators have been known to attack people (In the US : 17 fatalities in the past 50 years) so giving them a wide berth is certainly not ill-advised.


The video above from youtube shows why one should never feed wild animals, nor release exotic pets into the wild. This little fellow will one day be killed because he is no longer afraid of people and will get too big and go too far! Or he simply won't survive the Illinois winter! 


Quiet and peaceful

A New Year, A New Day: Overview

Today: I spent new year's eve on Fernandina Beach -- a quiet peaceful evening, until, of course, I returned to civilization and immediately encountered a group a drunken men, most laughing heartily at their unfortunate companion who was throwing up on the sea oats. This morning I awoke and went back to the beach to greet the first rays of sun, of this, the new year 2011. Pretty cool, huh? Ok ... I couldn't sleep so I went down to the beach and just happened to be there when the sun rose above the water. A nice way to start the day, no matter the reason. So, since I was up so early, I checked out and headed to the Okefenokee Swamp. Arriving at 7:30 a.m., I had the canoe loaded, submitted my float plan and hit the water by 8:00 a.m.. I returned at 3:45 p.m., having paddled 16 miles and 8 miles into the wilderness. It was what the doctor ordered. Then I drove three hours north to Hardeeville, SC where, now, I write and rest. Needless to say, I am really tired now so I am not sure how much will get written tonight. Posts will include: Canoeing with Alligators, Peat, More on Critters, More on Habitats, Geology of the swamp.

Amelia River in the Morning