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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!
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