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While exploring Cumberland Island many people are surprised to find pine trees in what is otherwise a hardwood forest. It’s not so much the pines themselves but how they are distributed that is a bit confusing. On Cumberland the live oaks are the dominant trees because they can withstand more wind and salt than other competing species, although there are places away from the salt spray zone that can support many other types of trees. By the mid 1800’s some of these areas had been cleared for agriculture. After the plantation era however farm fields were abandoned and eventually regenerated new forest growth. Under these conditions in this region the first trees to become established naturally are the pines; there is also a plot of planted pines on Cumberland.
Pine trees grow faster and require more sunlight than most hardwood trees. Pines have also evolved with a unique way to compete with hardwoods and that is their bark is more fire and heat resistant. If a normal ground fire burns the forest it doesn’t damage the pines but can destroy young broad leaf hardwoods that would eventually shade out future pine seedlings. Of course; if a fire is abnormally hot due to excessive burnable material; the pines can be killed as well.
There are four species of southern pines on Cumberland Island that promote natural fire on the Island. Standing straight and tall these trees make near perfect targets for lightning the main ignition source for forest fires. The distinctive scarring lightning makes on pines can be found on a number of trees around the Island. Pine trees that are hit almost always die but if a fire is started it will certainly benefit the other pines.
So the distribution of pine trees on Cumberland is the result of what man has done here historically and what has occurred here naturally. Over time without human intervention a more natural balance of plant species will develop on the Island and the pines will certainly be a part of it as long as fires are allowed to burn.
I was going to wait until June to report on fire; that’s when big thunderstorms develop in the area and produce lightning; the main ignition source for forest fires on the Island. But by mid May we have already had a lightning fire that has burned over two hundred acres; it seems like summer comes earlier than it used to.
Fire is a broad and complex subject, but there are a few things I would like to point out: if you take a walk through our southern forest the living things you see; all plants and animals either directly or indirectly need fire. Wild fires over time have shaped the evolutionary paths of many life forms probably more than we realize. As such; fire is now necessary to maintain the health of our wild-lands. To be more specific; fire is the natural cleansing and re-fertilization agent of the forest. Fire removes dead plant material, opening up the ground to sunlight so new growth can take place. Burning also controls parasites and diseases that can harm both plants and animals. Ash created from fire is like fertilizer on the ground that ultimately benefits future generations of wildlife. This is a process that has worked itself out over time but problems do occur when man gets involved.
Fire ecologists tell us that before Europeans settled North American wild land fires were a lot more common because no one put them out. The native Americans actually started their own fires to control insects and add fertility to the soil in order to grow food. As the new Americans spread out over the continent however fire became more and more of an inconvenience: homes were at risk from burning and forestry practices that placed a dollar value on trees alone took control. The hysteria over fire reached its peak during the first half of the 1900’s when hardly any wildfires were allowed to burn and large campaigns to prevent forest fires were initiated: most of us remember Smokey the Bear; all the while burnable material (fuel) was stacking up on the ground nearly everywhere creating a huge fire hazard and harboring an increasing number of insect pests as well as restricting new growth. After the catastrophic fires that followed, people started to realize the problems with fire suppression and that the native Americans probably had it right all along. At least; frequent small fires were much better than infrequent larger ones; the way our wild-lands originally evolved. In the last couple decades, fire management has come a long way with control burning programs to reduce excessive fuel loads. On Cumberland however, two thirds of the Island lie within a designated Wilderness area that restricts control burns but requires natural fires be left alone. This becomes problematic because under certain conditions, the huge fuel loads on the Island now, could quickly create a catastrophic fire that would possibly burn too much of the Island at once and in the precess destroy much of the wildlife and old growth trees as well as some of the historical buildings. But fact remains; the Island still needs to burn or eventually it will breakdown biologically. The National Park Service which is responsible for Cumberland’s fire management is aware of these and other issues, but forced with budget constraints and politics from several different directions the agency has a daunting task in managing fire. But we have just had a two hundred acre fire with favorable results. There are roughly another twelve thousand acres that need to burn at some point in time, mostly sooner than later. It is still early in the fire season so hopefully we will get another significant burn on Cumberland in the not too distant future.
SNAKE! Just the word can strike fear into the minds of those who are not familiar with these reptiles. Some psychologists believe people have a natural fear of snakes stemming from an earlier period in human evolution when our humanoid ancestors lived on the ground and had to frequently deal with venomous snakes. Whatever the reason, snakes have been feared and therefore maligned throughout at least recorded history from Biblical times to present day culture, resulting in greatly exaggerated tales that have added to the fear factor. As a result; many of these important animals have been needlessly destroyed over the centuries. In reality snakes have actually benefited mankind over time by helping to control rodent populations that can carry deadly diseases and also destroy agricultural crops. I’ve often thought if there was a choice between worrying about a dreaded disease out there I couldn’t see or where I put my feet when walking through the woods, I would opt for the latter.
On Cumberland Island eighteen species of snakes have been identified; three of these are venomous members of the pit viper family. The Eastern Diamondback rattlesnake is the largest. The record length for this beautifully marked reptile is over nine and a half feet although this specimen was not found on Cumberland. Fortunately, Diamondbacks are among the least aggressive venomous snakes on the planet and they try to avoid humans if possible while helping to keep the rodent population under control. The Canebrake rattlesnake is common on the nearby mainland but seldom found on Cumberland. Occasionally a Canebrake will enter a coastal creek and be carried to the Island by the tides; it’s unlikely there is a breeding population of these snakes on Cumberland. The Cottonmouth or Water Moccasin is our other pit viper and like the Diamondback is well established on the Island but tends to stay in or close to freshwater areas. More than the others, I find people fear the Cottonmouth. The story is this snake is aggressive and will come after you. Well, after spending nearly a lifetime in the woods and swamps of this region I have never experienced this and I’ve encountered hundreds of these snakes over the years. However, they will like other animals defend themselves; they do this by coiling up, putting their heads back and opening their mouths exposing the cotton white interior. At this point, usually the intruder gets the idea of what might be next even though the striking accuracy of this snake is not very good compared to its cousin the Diamondback.
On Cumberland we have relatively few snake sightings and most of these are of the harmless Black Racers that are more likely to be seen on the roads. The Black Racer is one of our snakes that will feed on other snakes: the Eastern King snake is another. There are a number of other snake predators on the Island such as hawks, owls and alligators.
Snakes however are survivors that have made many adaptations to cope with the various habitats they live in. The constrictors on Cumberland; snakes that kill prey by tightly coiling themselves around their victims; are also excellent tree climbers. Species such as both Yellow and Red Rat snakes can hunt the tree branches for squirrels and birds as well as seek out hollow tree cavities for their own safety.
Down through time snakes have been feared and demonized yet they are an important part of many functioning natural systems that have numerous benefits for mankind. With this in mind, the thought of a serpent in a perceived Garden of Eden is not such a bad thing.
Many people who visit Cumberland are surprised to learn there are mink on the Island. Most of our guest’s associate this member of the weasel family with more northern locals. Mink actually range all the way down to South Florida where an endangered sub-species known as the Everglades Mink still manages to survive. Throughout other parts of the south however the mink is not considered endangered but it’s an animal seldom seen by humans other than duck hunters or fishermen that spend a lot of time in this secretive animal’s wetlands habitat. Mose people though, have heard of mink due to the fact this animal’s beautiful fur has been used for years to make high dollar garments such as mink coats. Today captive, farm raised mink have taken over a large part of this market: one reason is fur coloration can be kept more uniform with ranched animals. On Cumberland I have noticed fur coloration can vary greatly among our wild mink from dark brown to a rusty red and even orange. Recently I was with a group of people as we watched a blond two foot long specimen work its way down the river bank on the west side of the Island. It was the first time I’ve ever seen this color phase.
Mink seem to be constantly on the move; either searching for food and mates or trying to avoid becoming food themselves. There are a number of predators that will feed on these small animals; hawks, owls and bobcats would all dine on a meal of mink. But alligators are probably their main threat in our area. Stomach samples taken from local alligators indicate they frequently take mink. The mink itself though is a formidable predator for an animal it’s size: birds, rodents, fish and small crabs are all part of their diet. Mink cover large territories and many use several denning sites along the way, complicating the efforts of anyone who is trying to observe these illusive animals.
On our Cumberland outings we talk a lot about the Island’s wildlife. If we can get a glimpse of a seldom seen species it can be a memorable experience for some people and a touch of mink always helps.
While Cumberland Island ‘Greens Up’ in April, so does the nearly 8,000 acres of adjoining Salt marsh. This is also the month when the bird most associated with these wetlands begins nesting. Clapper Rails also known as Marsh Hens are a true symbol of the Salt marsh because this is the only habitat they live in; if you study the bird it’s easy to see why. Rails are laterally thin birds which allows them to move about freely through the thick grasses of the marsh. Their large feet help them swim and provide support on soft wet ground, while the bird’s long curved bill allows it to probe this muddy environment for it’s main food source, fiddler crabs and snails.
Clapper Rail nests have been described in bird books as grass made platforms on the ground. However, the one nest I observed was a loosely woven grass bowl in a thick clump of new growth Saltmarsh cord grass about one foot above the ground. Because this was new spring growth, the nest had been lifted another six to eight inches above the ground by the time the ten buff colored speckled eggs hatched. Young rails have dark fuzzy feathers and are able to leave the nest and feed themselves within a day or two of hatching. Although they are tiny and frail looking, the chicks quickly adapt to life in a landscape that floods twice every twenty-four hours with high tides.
Rails tend to be secretive birds and spend most of their lives hidden in the tall grasses of their environment. However, they are often seen in early mornings at low tide bathing and feeding along the shore of saltmarsh creeks that border Cumberland. This time of year as the marsh turns green again and life is being restored there, it’s good to know the hardy little Marsh Hen is an essential part of it.
