The Saw Palmetto

With the rains we have had recently on the Island, plants that burned in the summer fires are now recovering rapidly.  The first to show green in an otherwise charred black landscape were the saw palmettos which are also the dominant undergrowth shrubs on Cumberland.  Any way you look at it, the palmetto plant plays a major roll in our sub-tropical forest.  The thick cover from their broad leaves provides shelter for many species of animals.  The plant itself collects and concentrates calcium that is redistributed into the shallow layers of soil when leaves die or burn, enriching the ground around it.  Under certain conditions, palmettos can create a very hot, fast moving fire that scorches other plants but also helps to reduce parasites like bark beetles that attack pine trees.  The hearty saw palmetto seems to thrive in areas that burn frequently and can grow in either shaded forest or open, full sunlit habitats.

In the early summer, palmettos will sometimes bloom with sweet smelling flowers that are sought after by beekeepers for the high quality honey they produce.  After the flowers are gone, berries start to form in their place and are usually ripe by late summer or early fall.  This is a nutrient rich food source for animals like deer, wild turkeys and raccoons.  The early native Americans ate them too, but the sweet fruit has a very strong musky flavor so human consumption is based on an acquired taste.  The heart of the palmetto plant where new leaves are formed was also harvested as a food source by early inhabitants of this region.  I have always been amazed at how resilient, yet useful saw palmettos are while Cumberland Island supports many acres of them.

Sea Oats

I’m always glad to see September because it’s not long until the cooler days of autumn will follow.  This month of transition can have both hot humid days punctuated by mildly warm days depending on the unsettled weather typical of this time of year.  September is a time when noticeable changes start to happen on and around Cumberland.  Some of the highest tides of the year naturally occur during this month.  If linked to a tropical storm; lower parts of the fore dunes can be breached, flooding the inter-dune meadows, impacting some of the less salt tolerant plants that grow there.

Recent storm tides have already cut deeply into the dunes destroying most of the sea turtle nests this season.  However, it’s during these high water events that one particular dune plant is recognized for its beach stabilizing value.  Salt tolerant Sea Oats more than any other plant or man made structure can hold a shoreline together.  The long root system of this plant spreads out like a fine net under the sand holding it in place  Sea oats also have five to six foot tall leaves and stalks that slow the wind flow over the surface of the dunes which also helps to slow the movement of sand.  Probably the single most important plants on Cumberland are the sea oats because of this critical service they provide along with the beauty of the plant itself.  This is the time of year when sea oats change color from green to golden brown.  It is believed early explorers referred to Georgia’s barrier Islands as “The Golden Isles” after observing the seasonal color change of sea oats along the wild shorelines.

Today, any place where the land meets the sea, a degree of wildness still exist as these two systems struggle to reach a natural equilibrium.  In the process, shorelines are constantly on the move either building or washing away.  This of course, is one of many reasons why coastal development is such a risky business.  A number of people who live on beach front properties are starting to realize now they may lose the battle against the sea. 

Fortunately most of Georgia’s shorelines remain undeveloped.  Nearly all of this state’s barrier islands were too far from shore to build bridges for access in the earlier years which restricted development.  By the time the will, technology and money came along to build bridges and develop the islands, either the State or Federal governments had already acquired and preserved these beautiful and highly functional natural areas.  Cumberland is the best example of this with over seventeen miles of undeveloped shoreline, that will never be developed due to protection from the National Park Service and some of the private owners as well.  

Visitors to Cumberland are always amazed to see so many miles of beach without a building in front of it as they comment on the natural beauty of the island; soon an awareness sets in as people realize how much of the southeast coast has been altered by heavy development.  

September is a good time to study the dynamics of how natural shorelines work and to reflect on how important it is to preserve them.

Storm Season

We are entering into a time of year when tropical weather systems become more of a threat to our coastal areas.  Tropical Storm Fay has already touched Cumberland leaving a large accumulation of downed tree limbs and other vegetation.  The storm also brought to shore one of the largest deposits of seashells found on the beach in recent years.  Shell collecting opportunities among the few Island visitors has been more than they could have hoped for; with many different types of shells covering some parts of the beach.  Rain from the storm also exposed fossilized bones and sharks teeth along the main road on Cumberland where road improvements are being made by the Park Service.  The much needed rain has also triggered an explosion of new plant growth on the north end of the Island that burned from a forest fire just two months ago.  September is usually the wettest month on Cumberland which brings relief from the normally hot days, but it is also the peak of the hurricane season so like other people who live on the coast we have to keep close tabs on the weather.

In the meantime though, other natural processes occurring during this unsettled time of year are worth mentioning.  Some early migrations of birds are either arriving for the winter of passing through the Island now.  Migrants such as Ruddy turnstones, Oyster catchers and Tree swallows are already here, while laughing gulls and royal terns that have been in the area all summer are changing into their winter plumage.  In the forest, the loud raucous breeding calls of the annual cicadas add a sense of urgency to the late summer season as well.  The racket created by these large fly looking insects may reach one hundred decibels and can hardly go unnoticed by anyone visiting Cumberland. 

A few Islanders now are on the lookout for the wild muscadine grapes that become ripe during this season.  Muscadines have a sweet rich flavor and are a delicacy in our southern woodlands.  Many of the lower growing, easily accessible vines are located close to the beach behind the main dune area.  However, tropical storm Fay has significantly damaged these plants with blowing sand and saltwater, reducing the number of grapes available for both human and wildlife consumption.

  Life by the sea can be harsh, particularly this time of year as tropical weather systems pass through the area; but it’s an interesting time to be on the Island and witness the urgency of this season.

Sharks

It’s mid-summer on Cumberland and the salt marsh is teeming with young fish and shrimp growing up rapidly in these nutrient rich waters.  Blue crabs are mating now and are regularly seen in shallow areas along the shore where three to five foot long bonnet head sharks move in to feed on them.  In an area so productive for small marine and estuarine animals, it’s only natural that the larger predators would be here too, and it has been that way for a long time.

On these hot summer days one of the favorite activities of visitors is to walk the shaded main road searching for fossilized sharks teeth.  Recently, the National Park Service has been filling low areas in the road using sand and crushed shell from a man made island on the south end of Cumberland.  The spoil bank was created when a nearby boat channel was dredged long before Cumberland became a National Seashore.  As a result, fossilized bone fragments from prehistoric animals along with sharks teeth were brought up with the rest of the fill.  Searching for these ancient relics has long been a past-time for both Island residents and visitors, but with recent park road work, it has become even more so.  Of course, those involved in this activity want to find the largest specimens which come from the ancestor of the great white shark, a predator that reached a body length of over fifty feet and had teeth as big as a human hand.  A few specimens this size have been found on Cumberland, but many more smaller teeth from a number of different species are much more prevalent.

Sharks go back about three hundred million years in the fossil records and today there are still at least twelve species that inhabit the coastal waters of Georgia.  During the summer months they will move into the shallow areas near shore to feed, especially on incoming tides at dawn and dusk.  Surf fishing for red fish is a popular sport on Cumberland this time of year and in the process some sharks are usually caught also.  Most of these are bonnet heads, black tip and lemon sharks.

Visitors often ask if it is safe to swim here.  All I can say is there has never been a recorded shark attack and people swim and surf off the beach all the time.  But one has to use some judgement also by not thrashing around in the water on an incoming tide after sundown when sharks are more likely to be feeding.  These sea going predators are actually very common in the waters up and down the east coast and anyone who has ventured into the ocean most likely has been close to a shark.  On Cumberland a few people get to see bonnet head sharks feeding in the salt marsh creeks this time of year along with some sharks caught off the beach by fishermen.  But lately, most visitors have been searching for the fossilized teeth of sharks that lived here millions of years ago.

The Big One

Well we finally got the big fire we needed by late June and into July.  A lightning strike in a most inaccessible place started the fire a long way from any roads and trails on the north end of Cumberland.  This was a welcome addition to the fire we experienced six weeks earlier farther south on the Island.  The current fire however burned a major portion of the north end and when it was over had consumed over 2,500 acres.  Most of this forest had not burned in years, so there was a huge fuel build up.  Combined with low humidity and windy conditions the fire burned fast and extremely hot in many sections, even killing some of the pine trees that would have normally survived a less intense fire; a vivid reminder that frequent smaller fires are less destructive than infrequent larger ones.  But the charred forest is already showing signs of recovery as new green plants are coming up through the ashes and have attracted deer and some smaller animals back into the area.

One of the hottest sections of this fire was in the scrub area that borders the North Cut road on both sides.  This scrub type habitat is just that; an assortment of thick, low growing plants that actually need and thrive in burned over conditions.  The last time North Cut burned through was in 1981 when a 1,700 acre lightning strike fire swept through the area, a similar situation to what has recently happened, but public reaction to that fire was much different.  During the 1981 fire there was a lot of pressure on the National Park Service from the general public to put that fire out and “save the forest” even though the Park Service knew then it needed to burn in order to stay healthy.  Another problem was the presence of houses in and near the burn area, however these buildings were ultimately protected from any damage.  In our recent fire there were eight state and federal agencies involved in the protection of the houses on the north end of the Island (some of which are historical buildings) and as a result there was not any damage.  On the other hand, outside of a few special interest groups, the outcry from the general public to put out the fire was not there as it was in 1981.  This might be partly due to the lessons learned from the widely publicized Yellowstone National Park fire in 1988.  At the time, people from all over the country were outraged that the park service let that fire burn as much as it did.  So the agency was under a lot of pressure to put it out, which they eventually did.  But soon after, the public could see for themselves the benefits of burning, as that area recovered with a lush new generation of plant and associated animal life.  This is the phase we are entering into now on Cumberland with these fires, and the Island will be much better off as a result.

The Armadillo

That sudden crashing sound through the palmetto undergrowth you hear when walking along the roads and trails of Cumberland Island is most likely from an armadillo.  The nine-banded armadillo is an animal native to South and Central America that was introduced into Central Florida by man in the 1920’s.  Since then, they have expanded their range north well into South Carolina and West to Mississippi, where they have now joined with a western population of the same species that entered south Texas from Mexico.

Somehow armadillos found their way to Cumberland by 1974; one explanation is they might have tried to cross tidal creeks on the mainland and the strong currents brought them to the Island.  This has been documented with other animals so biologists believe it to be possible with armadillos, which in spite of their heavy looking shells, are good swimmers.

It’s the hard shell covering the back and sides of this animal that makes it so distinctive from other mammals we have on the Island and also very noisy when they run through the bushes.  The armadillo is often referred to as a prehistoric looking animal and they do go back away in evolutionary time.  One of the indications of this is that their body temperature can be altered by outside temperature from fifteen to twenty degrees; but not totally like that of a reptile.  Armadillos are actually sensitive to weather extremes, so on very hot or cold days they can easily dig a deep burrow in the island’s sandy soil and stay under ground where temperatures remain fairly constant in a comfortable range.

More than anything else, armadillos are adapted for digging and rooting the ground where they find insects, their main food source.  However, this member of the anteater family will eat other animals such as small snakes and moles, even some plant material.  The armadillo’s mouth though, is equipped with only pre-molar teeth which limits their diets to mostly insects they can readily smell six inches under the ground with their sensitive noses.  Over the course of a year one armadillo may consume up to two hundred  pounds of insects; a lot of protein for an animal that only weighs about fifteen pounds.  Except for the coat of armor an armadillo actually looks a lot like the native opossum, which unlike the armadillo, is a marsupial.  But that doesn’t keep the local lore from comparing the two.  As a result, on Cumberland, the armadillo is often referred to as “possum on the half shell”.  The armadillo does not have a pouch for its young like the opossum does, but they do have a unique reproductive system that always produces four young; identical quadruplets; all the same sex.  The advantage of this could be that it lessens the chance for inbreeding.  Whatever the reason though, armadillos are truly unique animals and they certainly get your attention when they go crashing through the palmetto undergrowth.

The White Deer

The early morning birding tours we conduct from Greyfield Inn always include a drive and walk through the Dungeness area near the southern end of Cumberland Island.  There is a large population of the native white-tailed deer at this location but what makes them unusual is that some of these animals are totally white all over.  The first thing people ask is are they albinos?  Well, not really, at least they do not have pink eyes like true albinos; instead their eyes are brown like their brown relatives.

Relatives are the key factor here because these white deer seem to appear in isolated herds where there is more of a chance for inbreeding.  It is easy to see how this can happen since white-tailed deer naturally stay close to home.  If not disturbed by some catastrophic event, these animals will range within a quarter of a mile of where they were born.

Over the last twenty-five years I have noticed an occasional white deer in the herd from time to time.  Most of these animals were not all white either and some had other distinguishing features such as shorter legs and flatter noses also known as pie-bald deer.  More recently though these totally white deer that have the same body shapes as the other deer are becoming more prevalent.

Right now in the Dungeness area there are five white deer.  Last year a white doe had a pair of white twins that are both young bucks, now starting to grow antlers.  This year the same doe had another pair of white twins.  On the north end of the Island we recently encountered another white deer with mostly brown markings on its head and ears.

These white deer of course really stand out in the forested areas but blend well with the large sand dunes near Dungeness where we often see them.  Where ever they are seen though, they are popular with Island visitors especially photographers and have become an added attraction to our early morning birding tours.

The Manatee

As we looked out over the salt marsh creek the rounded shape of a gray mud bank glistened in the early morning light: then it moved.  At this point I could see it was a huge manatee.  Not often are the native animals mistaken for geographical features but because of their size; up to fifteen feet long and nearly three thousand pounds; these slow moving aquatic mammals can sometimes be confused with the landscape.  More often though, they are not seen at all as they lie just below the surface of the water and only bring their heads up momentarily to get a breath of air. 

At first glance the head of a manatee has a likeness to that of a walrus, but that’s where the similarities end.  These warm water herbivores are a class of animal more closely related to elephants than seals.

As one might suspect, manatees have big appetites and can consume between sixty to one hundred pounds of aquatic vegetation every day.  Around Cumberland they feed mostly in salt marsh creeks where they find Spartina grasses and algae.  Manatees can live in both fresh and salt water as long as it is above sixty-four degrees.  However sixty-eight degree water will start them moving south to warmer areas in the winter; like the spring fed rivers in Florida where seventy-two degree water comes up from underground to create these waterways.

In the salty waters around Cumberland, manatees are attracted to any areas that have fresh water draining into them.  Many times they will gather around docks while people are washing their boats to drink the fresh water run off.

In recent times boats have become a major problem for these large slow moving animals.  Of course, manatees evolved in an environment without boats and few if any other threats from above.  After man arrived though, things started to change.  The early native Americans hunted them for food:  spearing them from above the surface of the water.  Naturalist and explorer, William Bartram, in the late 1700’s gave a vivid account of a native American manatee hunt in Florida.   As Europeans took over the region, harvesting manatees for meat continued but with more sophisticated equipment, like harpoons and fire arms.  But even with this relatively new form of predation, these surface dwelling animals managed to maintain a significant population.  Now modern man has outlawed manatee hunting but also has brought with him that technological wonder, the powerboat.  As a result:  most all wild manatees today have prop scars and many have been killed by powerboats.  When boaters approach a dock on Cumberland, the first signs they see are usually the ones that warn them to slow down for manatees  In other areas, mostly in Florida, speed limits and refuges excluding boats have been established.  Some of these areas are controversial and much has been written and debated about them especially in heavily developed locals where of course, there are large numbers of power boaters that want quick access to fishing areas and other water related activities.  Fortunately, Georgia does not yet have the Coastal human density problems that are found in Florida so boat traffic is much lighter.  In the future though; if this type of development should occur; especially with large marines that attract powerboats, the natural behavior patterns and physical well being of the manatees around Cumberland Island could be in jeopardy.

 

The Ghost

If you have never seen them before, the ghosts can be startling on the summer beach at night as they race across the illuminating beam from your flash light. After sunrise they are still there, but blend well with the beach and are often overlooked. If actively pursued though, they can move swiftly, changing directions instantly; and should these evasive actions not be enough; they can quickly disappear into a burrow already dug some where.

With a carapace of only two inches wide the ghost crab is well named and well adapted to its environment. Like other crabs with gills, the ghost must return to the sea to breathe, but they also have the ability to store enough oxygen in their bodies to spend most of their time on shore. Along with speed and amazing agility, ghost crabs have eyes on vertical stalks which allows for a 360 degree range of vision; also equipped with two strong claws the ghost crab is a formidable predator for an animal its size. On the beach and in the dunes of Cumberland Island they eat just about any type of small land or sea animal they can capture. However they are also scavengers and will feed on the decomposing bodies of larger animals. Ghost crabs are significant predators of baby sea turtles; they will often burrow into turtle nests and eat the eggs, but will also capture the hatchlings on the beach as they make their way from the nest to the sea. It’s not uncommon to see the remains of several baby turtles at the entrance to a ghost crab burrow. Of course there are larger predators about that will eat ghost crabs; sea gulls, raccoons and feral hogs will all make a meal of them. The crabs try to avoid these larger animals by digging burrows three to four feet deep. This works most of the time but a large hungry hog will dig them up and may excavate a huge hole in the process.

The beach on Cumberland Island attracts a lot of animals from both land and sea. This is a place where the life and death struggles of many species can be observed. During the warmer months the ghost crab is a major player in this drama. But as the weather turns cooler in the fall the ghost will disappear into its burrow where it becomes dormant for the winter. It doesn’t take long for wind blown sand to cover the entrance of a crab burrow and for at least half a year there are no signs of these animals at all. But when temperatures once again rise in the spring, the ghost will re-appear.

Terns

It is June and the terns have returned to Cumberland: two species in particular are most noticeable this time of year. The Least tern is only here during the summer and will nest on the Island. As their name implies, they are the smaller terns, only about nine inches long but feisty little birds that defend their nests against intruders. Least terns form loosely defined rookeries near both ends of the Island; being ground nesting birds they require broad areas of undisturbed high beach for this purpose. Many beaches located in the Least terns nesting range have been developed or otherwise impacted by man so suitable rookery sites and feeding areas are disappearing; making this fish eating bird an endangered species, and also making Cumberland’s beach a more valuable asset for their survival.

The much larger Royal tern is nearly a permanent fixture to Cumberland’s beach with a resident population in the area of almost year round. These elegant looking birds are also breeding this time of year but they do not nest on Cumberland: instead they will form large, dense and noisy rookeries on smaller islands or high sandbars where there are fewer nest raiding raccoons.

Cumberland’s beach however is a good place to observe the courtship process of both Least and Royal terns which can be a drawn out affair with a lot of posturing and body language. Finally when a male thinks he has a prospective mate he will present her with a fish; if she accepts the offer there is a good chance they will mate. Over the years though, I have seen a number of these guys standing around with dried out looking fish in there bills; apparently not all of the girls respond. To some this may sound more like a singles bar than a sandbar, but it is all part of the natural selection process where only one good tern deserves another.