By Mary Pringle for The Island Eye News
This is shaping up to be a banner year for loggerhead nesting. All over the state DNR volunteers like the Island Turtle Team are reporting heavy nest numbers. The Isle of Palms has broken its previous May record of 14 nests in 2017 and Sullivan’s Island has its first ever recorded May nest laid near the lighthouse on May 28 with four false crawls near there in two days.
Time will tell if this will be a very early season as it was in 2017 or a very heavy season as it was in 2012. In recent years no new nests have been laid here in August.
On Memorial Day Christel Cothran pulled off a rare turtle nest “hat trick” by finding three nests at the north end of the Isle of Palms.
She came upon tracks on the beach at the Wild Dunes Property Owners’ Beach House and reported them. Soon after that she saw more tracks at Ocean Club Villas near the 18th green of the Links Golf Course, and then she found more on the beach at Ocean Point. All three of these sets of tracks led to a disturbed “body pit” where these three loggerheads had laid eggs. Two of the nests had to be relocated to a location at 23rd Ave. because of the flat wide beach with no dunes where the first King Tide would likely flood the egg chamber. The third one at Ocean Point was left in situ to incubate.
Although it’s not a requirement for our records, we always measure the width of each track of a nesting turtle. We find the length between the diagonal V marks made by the one claw on each of her rear flippers – the larger the distance, the bigger the turtle. We are finding that many of our nesters are on the smaller size, perhaps because they have recently entered the breeding population. Researchers are finding by inwater research studies that there are now very large numbers of young adult turtles. They theorize that this could be the delayed result of the nest protection efforts of groups like the Turtle Team in the last 25 years on the South Carolina Coast. The first nest that Cothran found had small tracks and a small clutch of 80 eggs. The second nest of the morning had medium sized tracks but a very large clutch of 150 eggs. The third nest’s number will remain a mystery until it hatches and we do the post-emergence inventory.
Her tracks measured the largest of the three.
Sometimes a female’s tracks will reveal interesting things about her. Does she have an abnormality from having lost all or part of a flipper to a shark attack? Does she have a large number of barnacles on her plastron or underside that make drag marks in the sand? On occasion we can recognize when a loggerhead returns to renest during the season from seeing these interesting characteristics. A few years ago there was one we called “Stumpy” because she had lost a rear flipper. That made it difficult for her to dig a hole for the eggs, and her nests and tracks were very distinctive.
In this time of drought, relocating a nest to a safe place can be a problem. On Memorial Day we found that the sand was so dry and powdery that digging a new egg chamber was difficult because hot dry sand kept falling into the hole. This is not a healthy condition for the eggs we were trying to bury in the hole. They have pores for oxygen exchange, and if these get clogged with dry sand, then it may affect the development of the eggs underground. Another problem is extreme heat. To produce healthy hatchlings, loggerhead nests should ideally incubate at least 55 days – the hotter the incubation temperature, the earlier the hatch date. If there is too much heat, and they develop too quickly in less than 48-50 days, the hatchlings may not be strong enough to make their very difficult migration in the ocean. That’s another reason to hope that June and July will not be as hot and dry as was late May.
Mary Pringle has been the Project Leader for the Isle of Palms/Sullivan’s Island Turtle Team since 2000. It is one of about thirty nest protection projects under the South Carolina Department of Natural Resources. She is also on the Sea Turtle Stranding and Salvage Network.