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AN OUTLINE OF FLORIDA'S FASCINATING TURTLES

                                                                          Andy C. Highfield

 

If you were to ask most visitors to Florida to name the most interesting natural environment, the word that would come up most frequently is “Everglades”. While it is perfectly true that the Everglades do represent a remarkable ecosystem, and contain a spectacular amount of biodiversity, they are far from the only unique environment to be found in this fascinating State.

 

Driving from one end of Florida to the other, the first thing that strikes you is the difference in human density and development. In the South, development has occurred at a tremendous pace, placing severe strains upon natural resources and space. This is also the driest part of Florida, and water resources are under acute pressure here. Droughts and water shortages are a growing fact of life for residents.  Roads have also intruded almost everywhere, and with them comes an increased toll in wildlife casualties. Tortoises, turtles and roads are, unfortunately, a particularly bad combination. In the North of the State, human density is much lower, and many more areas remain (as yet) in pristine condition.

 

There are a great number of highly specific habitat types in Florida, both aquatic and terrestrial. In the terrestrial category, we note Sand Pine scrub, Pine Flatwoods, and Longleaf Pine Sandhills. Fire is a natural occurrence in these habitats, and regular surface ‘burns’ (started under natural conditions by lightening), help to thin out the overgrowth of understory and is a required ‘trigger’ for certain species of seed to germinate. Such habitats are said to be ‘Fire Adapted’. In the absence of regular fires, the understory vegetation builds up to dangerous levels, non-adapted alien plant introductions thrive, and rare native biota that are very habitat niche specific are ultimately displaced. In these habitats, then, periodic fires (usually every 10-12 years and in some cases, more frequently) are a necessary part of the renewal cycle. These habitats are also occupied by the Florida Gopher tortoise, Gopherus polyphemus.

 

One of the first things that ‘tortoise people’ ask when learning about this fire cycle, is “what happens to the tortoises during these fires – aren’t they all killed?” The answer is “No, not often”, or at least not as long as the natural order is permitted to run its course. If fires are prevented for extended periods however, the fire – when it does come – will have an excess of dry fuel to feed upon, and temperatures will rise far higher than they would if more regular, but ‘faster’ fires take place. In these circumstances, wildlife casualties will be much higher. According to Ray Ashton, who has studied these animals extensively over many years, the tortoises have a keenly developed awareness of smoke in the air, and head for safety down the nearest burrow at the first sign of danger. There, they can sit out most fires of normal density and duration without suffering even a singe. In addition to providing much-needed protection in the event of an inferno, these burrows also provide a critical humid microclimate, which is utilized extensively. In the same Pine Flatwoods, and also in Mesic Hammock habitats, the unique Florida box turtle, Terrapene carolina bauri may be found. When one encounters it on its typical natural substrate of pine needles, it is immediately clear why it has evolved that characteristic carapace marking. It is an excellent camouflage in these conditions.

 

In addition to a wide range of terrestrial habitats, Florida possesses a bewildering array of aquatic habitats. From some superb sea-turtle nesting beaches, to marshy coastal wetlands that are ideal for Diamondback terrapins (Malaclemmys terrapin), and some of the finest freshwater, spring-fed rivers to be found anywhere in the world, it is no wonder that Florida hosts such a diverse range of turtle inhabitants. In all the time I have spent in Florida, some of my favorite destinations for ‘turtle watching’ are the Suwanee, Withlacoochee, Crystal and Rainbow rivers.  It is well worth taking out a boat, a pair of binoculars and a long lens (if you are keen to photograph the turtles you will undoubtedly meet along the way), and spending a day or three meandering along in search of ‘turtle heaven’! The most common species you are likely to encounter are the Cooters. These very large turtles (up to 16 inches or 41 cm in the case of the largest subspecies, the Suwannee Cooter, Pseudemys concinna suwanniensis) will typically be observed basking on logs and partially submerged branches. The Suwannee Cooter has a fairly restricted range. A similar, but much more widespread species is the Peninsular Cooter, Pseudemys floridana peninsularis. Just slightly smaller than the Suwannee Cooter (to about 15 inches or 38 cm) it has almost identical habits. One of the most distinctive and immediately recognizable turtles you are likely to see basking on a log is the Florida Redbelly turtle (Pseudemys nelsonii). With a very dark, almost black carapace with bright red marginals and plastron, it is clear where this turtle gets its name. The best places to see this turtle are along slow moving rivers with abundant aquatic vegetation. It frequently shares its chosen perch with the Yellowbelly slider, Trachemys scripta scripta. If you see large turtles basking on a half-sunken log, or perched on an overhanging branch in Florida, the chances are they will include one or more of the species just mentioned.

Common Snapping turtle

Slow moving waters are also a good place to keep an eye open beneath the surface for evidence of softshell turtles. These tend to be found in marshes, ponds, wide drainage ditches, and tributaries. The most common species is Apalone ferox, the Florida softshell. These very large turtles (up to about 20 inches or 50 cm) glide along like pale ghosts, just below the surface. If you see a softshell out basking, it is almost certainly a ferox. The other, less common softshell species found in Florida rarely bask.

Common Musk Turtle

Slow moving tributaries, drainage ditches and pools are also great places to look for some of the more secretive denizens of Florida’s freshwater habitats. Ditches and streams with heavy vegetation tend to be especially rewarding sites to study. Here, you may find the Common Snapping turtle, Chelydra serpentina. I ended up rescuing one from the middle of a busy highway! Watch your fingers in such encounters….

Sternotherus minor minor (Loggerhead Musk turtle)

Equally fascinating animals to locate are Mud and Musk turtles. Florida is home to several species. These are often found in drainage ditches, but cypress trees along the edges of rivers are also a great place to look. One of the most attractive species is the Loggerhead Musk turtle, Sternotherus minor minor, but the Common Musk turtle Sternotherus odoratus is more frequently seen. Both of these species can climb to a quite amazing height up near-vertical surfaces, and often hang off branches above the water, falling in suddenly with a loud splash at your approach. If you are especially lucky in Florida, you may see the so-called ‘Chicken Turtle’, Dierochelys reticulata chrysea. This is an interesting species, with very secretive habits. Attaining a length of about 10 inches, or 25 cm, look for it in backwaters, marshes and quiet ponds.

Chicken Turtle

In summary, Florida has a lot more to offer the visitor than Disney and Orlando! While tannin-tinged backwaters might not appeal to the more orthodox visitor, they are guaranteed to set the heart of any dedicated chelonian enthusiast racing!