| Which Sea Turtle is the Most Frequent
Visitor to North Carolina's Coast? 30
March 1998
The loggerhead turtle is the most common sea turtle occurring
along our coast. More than 99% of the nesting sea turtles
in North Carolina are loggerheads. So named because of their
massive head, loggerheads are one of five species of marine
turtles that inhabit North Carolina's waters. The other
less frequent visitors to our coast include Kemp's ridley,
hawksbill, green, and leatherback turtles.
Like most sea turtles, loggerheads only come out of the
water to nest. Prior to the nesting season, which occurs
from late spring through summer, mating takes place offshore,
just beyond the surf. The female then lumbers ashore at
night in search of a suitable site for her nest. She typically
seeks a spot above the high tide line on an isolated beach.
Using her rear flippers, she digs a flask-shaped egg chamber
where she deposits approximately 100 leathery-shelled, golf
ball-sized eggs. She then covers the nest with sand before
returning to the sea. A female usually nests every two to
three years but she may lay as many as five clutches of
eggs during a nesting year.
Temperatures play a key role in the development of the
eggs. Eggs incubated in cooler sand take longer to develop
than those in warmer sand. Temperature even determines the
sex of the baby turtles -- eggs in warmer sand produce females,
while cooler conditions produce males.
After a two month incubation period, the hatchlings break
out of their shells and make their way to the sea. These
two-inch turtles face many hazards as they make their way
across the open beach. Many fall prey to predators such
as ghost crabs, gulls, and raccoons. Others may become disoriented
by the lights of oceanfront developments or trapped by vehicle
tracks in the sand. Weather extremes and storm tides may
also hamper their trek to the sea. Those that do reach the
water are faced with their natural enemies -- sharks, bluefish,
and grouper.
What happens to loggerheads once they reach the ocean is
still a mystery. Biologists believe that these young turtles
spend their first years floating in seaweed mats and feeding
on the small invertebrates that live there. As they grow,
their diet changes to larger mollusks and crustaceans. Most
turtles never make it to adulthood. It is thought that perhaps
one out of 1,000 loggerheads live to reproduce.
Loggerheads and other sea turtles have roamed the world's
oceans for more than 150 million years. Now, however, their
survival is threatened by humans. Beachfront development,
increased boating and fishing, and pollution all contribute
to their declining numbers. All five species of marine turtles
found in North Carolina waters are listed under the U.S.
Endangered Species Act as either threatened or endangered.
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