Naturalist Fact of the Week

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Diamondback Terrapin (Malaclemys terrapin centrata)

The only turtle that lives entirely in brackish water is the diamondback terrapin (Malaclemys terrapin). This turtle is a habitat specialist, restricted to salt marshes, estuaries, and tidal creeks along the eastern and Gulf coasts of the United States. They are among the most variable of North American turtles, having an array of colors and patterns among the 7 subspecies. The species is sexually dimorphic in that the males grow to approximately 13 cm, while the females grow to an average of around 19 cm and have a larger head and jaws than males. They also have a variable diet depending on geographic location, but common foods include periwinkle snails, bivalves, crustaceans, crabs, and scavenged fish. They are primarily diurnal and usually spend the night buried in sediment. Juvenile terrapins are rarely encountered. It is unknown what turtles two years old or younger do, as they are almost never seen.

The diamondback terrapin was once a food staple so cheap that 18th-century tidewater slaves protested the amount of terrapin in their diet. In the 19th-century, though, the diamondback made an unfortunate transition from despised staple to gourmet delicacy. Even though the commercial hunt has largely collapsed, these turtles continue to decline due to coastal development, disturbance on their nesting beaches, road mortality of nesting females, boat injuries, and pollution. They continue to drown in large numbers in pot traps designed for crabs. Maryland, Delaware, and New Jersey laws require terrapin excluders on crab traps, and some states are considering requiring them. In Georgia the terrapin is considered a “species of concern”.

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Naturalist Fact: Manatee

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Naturalist Fact

By Mike

Manatee (Trichechus manatus)

http://animalscamp.com/wp-content/uploads/2011/11/Florida-Manatee.jpg

From: http://animalscamp.com/wp-content/uploads/2011/11/Florida-Manatee.jpg

Manatees are large aquatic mammals found in warm coastal waters including tidal rivers and estuaries.  Often called “sea cows”, manatees are in fact more closely related to elephants than they are to cows.  Being entirely herbivorous, manatees will eat large amounts both saltwater and freshwater plants.  Manatees only have molars, which are used to grind up the plant matter they ingest.  In just one day a manatee may eat up to a tenth of its bodyweight, and they can be quite heavy.  Individuals are typically 8 to 13 feet in length and will weigh 440 to 1,300 pounds.  The average lifespan of manatees in the wild is 40 years.

 

Manatees prefer warm water, and tend to be found in regions where the water temperature is above 68 degrees Fahrenheit.  These gentle and slow-moving creatures will migrate north along the Atlantic coast during the warm summer months and can be found in the coastal waterways near Little St Simons Island throughout the summer.  Manatees spend most of their time resting and eating, but they can be playful as well.  Like all marine mammals, manatees must breathe air at the surface through nostrils, but can remain submerged for up to 15 minutes at a time.

 

Historically, manatees were often hunted for their hides, oil, and bones.  Being gentle and slow-moving made the manatee an easy target for hunters.  Today manatees are an endangered species, and they are protected by law.  Even with protection, manatees still face a number of threats including boat strikes and entanglement in fishing equipment.  On many individuals scars are visible where a wound from a boat has healed.

 

While it may be tempting to pet manatees or give them freshwater to bring them closer, these actions may negatively affect manatees.  Manatees may begin to associate humans or boats with these actions which can put them at higher risk for boat strikes.  If you do happen to have the exciting experience of seeing a manatee, the best thing to do is simply enjoy watching it interact with its natural environment.

Naturalist Fact: Cownose Ray

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Cownose Ray (Rhinoptera bonasus)

Photo from CheseapeakeBay.net

Photo from CheseapeakeBay.net

First things first: despite their common names of “cownose stingray” and “skate”, cownose rays are technically neither! Cownose rays are unique, so they belong to their very own family of rays. However, these interesting-looking ocean-dwellers can still pack a stinging punch, so avoid the venomous barb at the base of the tail. According to legend, Captain John Smith had an encounter with a cownose ray in Virginia, and the location still bears the name “Stingray Point”.

Despite these cautionary tales, cownose rays are known for their passiveness and will only sting when provoked. They are a common site along their shallow Atlantic coast migration path; found as far north as New England and as far south as Brazil. They often travel in large groups, called “schools”, that are formed based on the sex and age of the rays. Since they use their fins for locomotion, these underwater schools resemble flocks of large birds in underwater flight.

Cownose rays typically reach a wingspan of three feet, which comes in handy when they forage. The rays use their large fins to disturb mollusks in the seafloor sediments, and then they crush their prey using powerful dental plates.

On Little St. Simons, look for cownose rays along the edges of Mosquito Creek during a kayaking adventure—sometimes they even raise a fin to “wave”!

Fun Fact: The stinging barb on a cownose ray grows the same way as your finger nails, so the rays you see in “Touch Tanks” at aquariums are regularly clipped for safety.

 

Spring Birding Week 2013

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We just completed an incredible week of birding here on Little St. Simons Island! Our Spring birding week took place April 25th -May 5th, during which time we were graced with some exciting visitors.

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Red Knots feeding on Main Beach.

As Spring migration is coming into full swing, new birds have been arriving each day. Some, like the Red Knot, are in the midst of a 9,000+ mile trip North, stocking up on food to fuel the rest of their journey. We also witnessed an incredible “food event” as horseshoe crabs lined the beach in mass, laying their eggs in the soft sand and creating a buffet for hungry shorebirds.  Others, like the colorful Painted Bunting, have traveled to the area to breed before they return to  the Caribbean.

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Painted Bunting near the bird feeder outside of Cedar House.

Of course, with the birds came the birders! We were delighted to have renowned birders and naturalists here to lend their expert eyes and ears as we explored the island. This Spring we had Dr. Ray Chandler, ornithology professor at Georgia Southern University. John and Cathy Sill, who have authored and illustrated a series of books together, also spent time with us. Malcolm Hodges with The Nature Conservancy wrapped up the week sharing his love for birds and his unique interest in lichens. After the sun went down, they shared even more knowledge through presentations on topics ranging from how to migrate to how to draw birds to how to be an ecologist.

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John Sill offered a field sketching workshop one evening after dinner which offered a whole new perspective to birdwatching.

 

If you missed out this Spring, don’t despair! We have Fall Birding coming up September 25th – October 3rd, 2013. Look forward to spending time with Jim and Georgann Schmalz and John and Cathy Sill.

To see a complete list of the species we spotted over the week, check out our list below. We tallied up 95 species. SpringBirding20130001 SpringBirding2013(Click on the list to enlarge it for easier viewing.)

Horseshoe crab and shorebird bonanza!

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Horseshoe crabs gather in large groups at nesting beaches in the days surrounding full and new moons.

Having inhabited the oceans for over 350 million years, horseshoe crabs (Limulus polyphemus) are a glimpse into prehistory. We spot them most often as dead carcasses or molts along the shoreline. However, right now we are seeing hundreds of live, healthy, active crabs at the waterline.

Birders at Sancho Panza marvel at the horseshoe crab "arribada."

Birders at Sancho Panza marvel at the horseshoe crab “arribada.”

Horseshoe crabs spend most of the year in deeper waters, but in the late Spring they begin to move inshore to mate in large aggregations. Hundreds are gathering at Sancho Panza Beach here on Little St. Simons Island. Mating activity peaks around the full moon and new moon cycles, and with the full moon last week, we found big groups of males fighting for the chance to fertilize some eggs, and several indentations in the soft, wet sand where undoubtedly nests had been left behind.

A female will push several clumps of eggs down into the sand with specially adapted appendages. Each clump can contain two to four thousand eggs, and over the course of her spawning season, a female will deposit around 90,000 miniature eggs! Of those 90,000 eggs, only about 10 are expected to mature into adult horseshoe crabs.

If you are familiar with our island, you know that Sancho Panza is an excellent shorebirding spot, and right now we are in the peak of Spring migration. It is quite the spectacle to see a variety of shorebirds eating to their little hearts’ content at the buffet of horseshoe crab eggs! In fact, horseshoe crabs are instrumental in the journeys of at least 20 species of migratory shorebirds along the Eastern Seaboard.

Ruddy Turnstone feeding at a horseshoe crab nest. (Photo: Pete Oxford)

Ruddy Turnstone feeding at a horseshoe crab nest. (Photo: Pete Oxford)

Sanderling feeding on horseshoe crab eggs. (Photo: Pete Oxford)

Sanderling feeding on horseshoe crab eggs. (Photo: Pete Oxford)

Naturalist Fact: Lichens

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Crustose lichen commonly found on Southern Magnolia trees on LSSI.

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Foliose lichen on a Southern Red Cedar.

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Fruticose lichen on a downed oak branch.

 

Lichens can be found in several habitats across Little St. Simons Island, and they take a variety of forms and colors. Lichens have the ability to survive long dry periods, but after a good soaking rain, they will catch your eye with their bright colors and interesting textures.

Lichens are actually not a plant, but a composite of fungi and a photobiont that behave together as a single organism. The fungus usually provides the structure and facilitates the uptake of water and minerals, while the photobiont generates sugars through photosynthesis. The photobiont is usually a green algae, but can also be a cyanobacteria.  In most cases, the fungus and its photobiont would not exist outside of the lichen association.

Lichens have the ability to grow on soil-less surfaces, and therefore are one of the first colonizers in many plant communities. They are very slow-growing, but can derive most of their water and nutrients from the air and rainfall. On Little St. Simons Island, you can find lichens growing on the smooth bark of Southern Magnolias or Southern Red Cedars. You will also find it colonizing open sandy areas.

Lichens can be divided into three groups based on their morphology. Crustose lichens grow flat against hard surfaces (like a crust), and are the simplest form of lichen. As they grow, they radiate out from the center, so the newest growth is on the perimeter. Foliose lichens grow in a more “leafy” structure, but stay close to the surface they inhabit. Fruticose lichens are more shrub-like, growing on a stalk or exhibiting a highly branching, more complicated structure. On Little St. Simons, you can find lichens that belong to all three of these groups.

Nesting season begins!

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Wilson’s Plovers utilize our undeveloped beaches for nesting in the spring and summer months.

Nesting season is beginning to gain momentum, and so far we are have two Wilson’s Plovers nests and two Oystercatcher nests for this season here.

Former naturalist, Abby Sterling is starting the second field season of her two year Master’s project which involves monitoring nesting Wilson’s Plovers and American Oystercatchers here on Little St. Simons Island. She is also monitoring field sites on Little Cumberland and the north end of Cumberland Island. Abby’s project looks at nesting and fledging success as well as a variety of nest site characteristics to try to determine if different habitat features can be used to predict nest success and areas of high productivity.

Last year on Little St. Simons, we found 97 Wilson’s Plover nests, and had a little more than a quarter of them hatch.  Of the 25 nests that hatched, there were a total 55 chicks, all of which were banded.  The leading known causes of nest failure were washover from tides, avian predation, and raccoon predation. We had 17 American Oystercatcher nests, four of them hatched and we had seven chicks survive to fledging! The leading known causes of failure were washover from tides and raccoon predation. On Cumberland Island, on just the northern-most two miles of beach, there were 89 Wilson’s Plover nests and five oystercatcher nests found. The plover nest success rate was 5.6 % and none of the oystercatcher nests hatched. The leading causes of known failure on Cumberland were tidal overwash and coyote predation. On Little Cumberland we found 27 nests, had seven nests hatch and banded 17 chicks. There was only one Oystercatcher nest found, which washed over and failed.

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This Wilson’s Plover nest from last year was nestled safely amongst some beach vegetation.

We found nests quite far back on the beach in some cases, well behind the primary dunes. Other nests were located in the wrack line, which reiterates the importance of beachcombers staying below the wrack line on the wet sand during nesting season. Plovers nested out in the open sand, in wrack and in many cases, tucked into the vegetation. The data hasn’t been analyzed yet, but it will be really interesting to see if there are any relationships between these observations and nesting productivity.

This year Abby’s technician on Little Cumberland, Nathan Cross, found the first Wilson’s Plover nest on the tip of Cumberland on March 23.  It has already been lost, but he has since found a second nest that remains active and we found our first one here on April 1st.

Both the Oystercatchers and the plovers are showing signs of nesting. Since the middle of March they’ve been paired up and defending territories, but over the past several days we’ve been seeing many more scrapes created by both species. We do have pairs of Wilson’s Plovers quite vocal at all three beach access points (Mosquito Creek, Main Beach gazebo and Sancho Panza), and so its best to stay on the paths and below the wrack line when on the beach. Beach Pond is also an active area with several plover pairs and an Oystercatcher pair.

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This pair of American Oystercatchers has a nest scrape near Beach Pond, and we are expecting to see eggs very soon!

 

Living Shoreline promotes fish habitat and erosion control

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Barrier islands are very dynamic landscapes. As the tides, currents, and winds sweep around the island, it continuously changes the landscape. Where you first arrive to the dock at Little St. Simons Island, there has been a wooden bulkhead adjacent to the dock creating a vertical barrier between the creek system and the upland.

Imagine a section of healthy marsh joining the higher ground and the creek. That's what we invision as we replace this bulkhead with a Living Shoreline.

Bulkheads will weaken and eventually fail over time, and we have been planning on replacing the current bulkhead (constructed in 1995) for several years. However, rather than building another bulkhead that inevitably will have to be replaced again sometime in the future, we are putting in a “Living Shoreline.”

This Living Shoreline will be a more natural slope from the upland into the marsh habitat, and as the name suggests, create excellent habitat for the many organisms that utilize the different zones between the low tide mark and the high tide mark. We will be planting native plants that thrive in the marsh zones whose root systems will help stabilize the sediments, and using recycled oyster shells as structure to recruit new living oysters to the site, which will create habitat for myriad of marine organisms including several species of fish. To learn more about the benefits and implementation of a Living Shoreline, visit NOAA’s resource pages or learn about a similar project on Sapelo Island.

Tom Bliss with UGA's MAREX and Jan Mackinnon with DNR's Coastal Resources Divi

sion remove their nets after a fish sampling session.

Along with stabilizing the shoreline in a more natural and efficient way, one of the goals of this project is to enhance fish habitat. In order to get some baseline data on what is already hanging out around our dock, with the help of the University of Georgia’s Marine Extension (MAREX) team, we have been sampling the fish populations around the dock for the past year.

Next comes the construction! Scheduled to start in the middle of February, we will begin removing the old bulkhead, and creating the living shoreline. With the guidance of cicil engineer Tom Havens and landscape architect Thomas Angell who specializes in ecologically-sensitive environmental design, we will transform our current bulkhead garden into a seamless junction with the marsh.

In the meantime, as you park your car at the Hampton Marina, you might notice a mountain of oyster shells. As these are put into mesh bags (8,000 mesh bags to be exact!), they will be the foundation for which oyster spat (free-swimming larval oysters) will attach. Overtime, they will grow into a living oyster reef, one of those living oyster reefs that are vital to the functioning of the marsh ecosystem.

Of course, Little St. Simons Island cannot take on such a big project on our own. Our primary partners include: UGA Marine Extension, The Nature Conservancy, Sapelo Island National Estuarine Research Reserve, Georgia Department of Natural Resources, Coastal Resources Divsion, NOAA. We are also working with volunteers from these organizations to help implement the project: Coastal WildScapes, Americorps.

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Naturalist Fact: Spotted seatrout

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The spotted seatrout (Cynoscion nebulosus), also known as speckled trout, is a common estuarine fish that is found in the Southern U.S. and Gulf of Mexico. Despite its name, spotted seatrout aren't members of the trout family (Salmonidae), but the drum family (Sciaenidae). During spawning season, all mature males of the drum family attract females by making a “drumming” sound. They produce the sound by the contraction of abdominal muscles against the swim bladder, a gas-filled organ that contributes to the ability of a fish to control its buoyancy.

Spotted seatrout reach sexual maturity at one to two years. They grow rapidly, reaching 8 inches in the first year and over 12 inches

by age 2. Small trout eat large amounts of shrimp and other crustaceans, but as they grow larger, their diets shift toward fish. Studies in Texas and Mississippi show that really large trout strongly prefer to feed on mullet. Often the mullet is half or two-thirds as large as the trout! Large females may reach 12 years of age and release over a million eggs during spawning.

Spotted seatrout are a good eating fish and, according to the NOAA, are in the top ten species for recreational fishing in the United States. Seatrout are found in and around seagrass meadows, deep holes, in the surf, and above oyster bars. Fishing with live shrimp near the bottom or attaching a float is the most popular way to search for trout. Casting with soft-bodied jigs, top-water poppers and spoons can be effective also. Spotted seatrout is listed as a “best choice” for sustainable seafood by the Monterey Bay Aquarium's Seafood Watch.

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Naturalist Fact: Southern Flannel Moth

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Adult Southern Flannel Moth

The Southern Flannel Moth (Megalopyge opercularis) is named for the texture of its wings, and is found commonly in woodlands and forests in the Southeast. The adult moth emerges in the spring, after having overwintered in its cocoon. The moth will only live about 5-7 days in which time the female deposits her eggs one of a variety of woody plants.

The larva of the flannel moth, also known as the Puss Caterpillar, grows to no more than an inch in length and is covered in dense gray to tan hairs, giving it a furry appearance. The hairs appear to be combed into a crest at the to

p of its body and extend in a tail-like tuft from the back. Younger caterpillars’ hairs are white and wispier.

Puss Caterpillar

Although this caterpillar may look soft, it is armed with an intense defense strategy. Venemous spines are hidden beneath the tuft of hairs, and when agitated, this caterpillar can administer one of the most painful stings of any caterpillar found in the United States. The puss caterpillar feeds on woody plants, and it is not a stranger to the Live Oak dominated forests of Little St. Simons Island. If you come across this little creature, marvel at its peculiarity, but don’t pet it!

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