#18 - AMERICAN WHITE IBIS (Eudocimus albus)
Visitors to the Mound House frequently encounter flocks of white ibis wading the rocky shoreline, perched in the mangroves or patrolling our freshly mowed lawn in search of grubs and insects.
A very distinctive wading bird, the white ibis sports a long curving orange bill, orange legs and brilliant white plumage with black wingtips when mature. Younger white ibis are a brownish white.
The American white ibis can be found throughout the Gulf and South Atlantic coastal regions of the United States ,Mexico and Central America as well as the Caribbean. They are found in a variety of habitats from muddy pools to mangrove swamps, mudflats, cypress forests and even the manicured lawns here on Estero Island.
Feeding primarily on small fish, crabs and crayfish as well as insects, the white ibis readily adapts its feeding behavior to match availability. During the breeding season, ibis gather in large flocks. They are territorial and defend their nests against intruders with elaborate displays of bill snapping ,lunging and biting.
Sometimes, the American white ibis can be found foraging in mixed species flocks that include the glossy ibis, the scarlet ibis and even wood storks. Many of the white ibis observed on Estero Island will move inland to the coastal marshes as waters recede with the onset of the dry season. These lowered water levels concentrate forage species such as minnows and crayfish into much smaller areas making feeding easier for the ibis.
Native American folklore holds that the white ibis is the last bird to seek shelter before a hurricane and the first to emerge after the storm, making the ibis a first a harbinger of danger and later optimism as the “all clear” sign that the hurricane has passed. Fittingly, the white ibis is also the mascot of the Miami Hurricanes.
# 17 - THE MANGROVE TREE CRAB (Aratus pisonii)
There is an impressive array of wildlife living on the Mound House site. Some on land, some in the surrounding waters, and some perfectly at home in either environment, such as this weeks’ subject : THE MANGROVE TREE CRAB
The mangrove tree crab makes its home among the roots and branches of the mangroves that line our shore here at Mound House. They can be seen crawling high up into the top limbs or even crossing the road on occasion, making their way home after a long evening or on the way out to dinner. Thriving on a diet of plant and animal material including mangrove leaves, seagrasses, worms and small crustaceans, the mangrove tree crab is perfectly adapted to is unusual environment where it lives both in the water and on land. This makes the mangrove tree crab an important link in the conversion of plant biomass into zooplankton, which serves as component to the base of the estuarine food chain. Though extremely fast and able to scamper out of the way of most visitors, mangrove tree crabs are small and seldom exceed the size of a quarter.
Predation is tough on the mangrove tree crab. As larvae, they are preyed upon by a variety of other zooplankton, filter feeders like barnacles, hydroids and anemones. As adults, larger fish ,wading birds and even other crabs target this species.
CREATURE FEATURE #16 – FLORIDA STONE CRAB (Menippe mercenaria)
Slow moving, thick shelled and armed with enormous claws that can exert a force of over 19,000 pounds per square inch, the stone crabs which inhabit the rocky shoreline of Mound House are a remarkable testimony to millions of years of evolution. They are adapted to life on the sea floor with juveniles and young adults living in the estuaries and larger adults moving offshore to burrow in the the deeper grass flats or to inhabit rocky limestone ledges. They are well camouflaged with a mud colored carapace and sandy underside. Feeding on carrion and even seaweed if need be, the powerful stone crab prefers using its claws to break into shells of clams, oysters, conchs, whelks and other marine mollusks.
On the other hand, stone crabs are a celebrated Florida delicacy and, in season, their delicious powerful claws can be found served with melted butter and a side salad at your favorite seafood restaurant.
Stone crabs are harvested by commercial trappers, recreational trappers and even divers from October until May. Remarkably, the stone crab is a renewable resource. By law, only the claws may be taken, and the crab is released alive back into the water where it will regenerate new claws within a year.
#15 - SMOOTH BUTTERFLY RAY ( Gymnura micura)
Summer is the time in which the full and new moons bring extreme low evening tides to the beaches of Estero Island, and it is during these low tides that the sand bars become exposed for a few hours at sunset, separating the waves form the shore and leaving the water between sandbar and beach shallow, clear , calm… and teeming with marine life that is rarely seen in the turbulence of the waves washing ashore on a high tide. One of the more unusual species to be observed during this time is the smooth butterfly ray. He is a master of camouflage, and you must look closely to find him. Usually found on soft sandy bottoms, the butterfly rays found on our shores tend to be a light sandy color that blends in nearly perfectly with the bottom. They are wider than they are long, with a very short tail displaying two distinct horizontal bands. These small rays feed on fish, invertebrates and crustaceans. Butterfly rays are common throughout the Gulf of Mexico, the northern coast of South America, and the Atlantic coast of Africa. If you are wading in the shallows looking for one, these rays tend to move slowly away ,gliding just above the bottom and will often stop to fan themselves into the sand nearly disappearing from sight. Although this species of ray is harmless and has no poisonous spine, be sure to shuffle your feet, lest you step on him and feel the stinging pain of butterfly ray resentment.
#14 - LOGGERHEAD SEA TURTLE (Caretta Caretta)
The loggerhead is the most common of the five species of sea turtle in Florida and summer is nesting season here on Fort Myers Beach. All sea turtles are listed as endangered and threatened marine species and as such are protected by State and federal law. This is why the nest sites that we see on the beach are carefully protected with stakes, ribbon and cautionary signs. Each nest may contain up to 100 eggs buried in the sand and these tiny hatchlings, only two inches in length, can grow to be over 38 inches long and more than 400 pounds. But as hatchlings, they are at the greatest danger, non only from predators such as raccoons and sea gulls, but from fish and sharks as they enter the water. Unfortunately, many sea turtle hatchlings never make it to the water, hatching at night, they become disoriented by sea side lights on the beach and wander inland where they die from sun exposure ,predation or exhaustion.
Sea turtles live on a diet of, crabs, shrimp, marine mollusks and even jellyfish and have done so, virtually unchanged, for over 200 hundred million years.
|Loggerhead Sea Turtle|
One of the most attractive shells found on our beaches here on Estero Island is the olive shell. This small marine snail has a shiny delicately patterned shell and grows to about 2 1/2 inches in length. They can be found on the sandy bottom just below the low tide line and often burrow under the sand feeding on coquinas and other small bivalves as well as carrion. This marine snail lacks the operculum or “door” that so many of our marine mollusks have, and lives most of its life with its mantle (fleshy exterior of the body) wrapped around the shell, this constant polishing is what gives the olive shell its smooth, shiny appaerance. The olive shell has the distinction of being the State shell of South Carolina.
Here at Mound House ,our student visitors learn string these shells onto cordage braided from plant fibers, making bracelets and necklaces in the same way the Calusa did centuries ago.
|Olive Shell Varieties|
#12 - BLUE CRAB (Callinectes sapidus)
#11 - ATLANTIC WHITE SLIPPER SHELL (Crepidula fornicata)
Finding a glistening piece of sea pork washed ashore may leave you thinking you’ve found just a piece of some other creature, resembling a piece of waterlogged pork or fatback (yummy!) This “blob” is actually a living creature, a very complex colony composed of thousands of tiny zooids wrapped in a cellulose housing, each in its own tiny sack like body. This celluloid housing is called a “ tunic” and protects the colony. You will find two external openings near each other that serve to circulate sea water through the sea pork in which nutrients are filtered out as food . Sea pork lives on the bottom and attaches itself to rocks, pilings, jetties or seaweed and is washed ashore by storms and high surf. Bottom feeders such as skates, and even some species of sharks, are known to eat sea pork. There are over 1,000 species of Ascidians worldwide, with numerous species of varying colors including red, yellow ,white , greenish-blue, and even purple appearing on our shores.