By Peter Vankevich
The sea turtle nesting season on the Outer Banks has wound down and, despite the expected challenges, can be declared another successful year.
A total of 303 nests were documented in the Cape Hatteras National Seashore. Of this number, 101 were on Ocracoke —all loggerhead sea turtles except for one green and one leatherback, according to Michelle Tongue, Cape Hatteras National Seashore deputy chief of resource management and science.
A major threat to sea turtle nests on the Outer Banks is overwash, i.e., when high tides, waves and storm surge cover the beach. This affected 72 of the nests on Ocracoke at least once, she said in an email. Turtle nests can survive some overwash, especially those of short duration.
The major overwash events this season were the passage of Tropical Storm Debby in early August and the out-to-sea Hurricane Ernesto that moved north between the Outer Banks and Bermuda in mid-August, producing major swells and an unnamed cyclone which hit along with a King Tide event in mid-September.
Tongue said predation was far less significant than the storm impacts. Staffers noted some ghost crab predation at 49 nests, with 14 eggs killed at the most heavily impacted nest. These semi-terrestrial crabs can burrow into a nest and remove eggs.
No mammalian or avian attacks on sea turtle nests or hatchlings were recorded this season on Ocracoke. NPS staff look for crab and bird tracks in the sand where the hatchlings made their way to the ocean.
In total, 30 of the 101 total nests (29.7%) laid on Ocracoke this season failed, producing zero live hatchlings, while the remaining nests fared well with 81% average hatch success and 75% average emergence success.
An estimated 5,440 hatchlings emerged on Ocracoke this year, representing approximately a third of the estimated 15,631 hatchlings emerged to date throughout the Seashore, almost all of those hatchlings were loggerheads with an additional 110 green sea turtle hatchlings.
The single leatherback nest on Ocracoke failed with no hatchlings or viable eggs found during the nest inventory, which occurs well after the 60-day incubation period. The leatherback nest on Hatteras also failed. Later DNA analysis will determine if the two nests were laid by the same female.
Leatherback sea turtle nesting on the Outer Banks is rare. In 2023, Ocracoke had its first successful leatherback nest in years with 71 hatchlings that emerged from the 93 eggs laid.
The 56-mile Cape Lookout National Seashore, from Portsmouth Island to Beaufort Inlet, had an average sea turtle nesting season, with 278 nests documented, per Jon Altman, its chief of resource management. Of these, 50 nests were lost from storm overwash and some coyote predation.
In this Seashore, there was a combined total of 10,684 hatchlings. The vast majority of the nests were loggerheads, with 11 green nests and two Kemp’s ridley nests, only one of the latter which was successful.
“We also had three leatherback nests, but none of the nests emerged,” Altman said. “It appears the eggs were infertile as there was no embryo development.”
Statewide, along the approximately 330 miles of seashore, the number of sea turtle nests were down from 1,723 last year to 1,388 this year.
“It is lower than the 2023 total but is almost exactly the average number of loggerhead nests laid per year, or 1,377 nests, based on the previous 10 years of data,” said Matthew H. Godfrey, a sea turtle biologist for the NC Wildlife Resources Commission, in an email. “Variation in the annual number of nests laid is typical for sea turtle populations.”
So, out of the 1,388 nests in the state, 88,658 hatchlings emerged, according to Seaturtle.org, an organization that supports research and conservation of sea turtles. These high numbers are vital for population resiliency. The estimates for the number of hatchlings that make it to full adulthood vary considerably and no one really knows, but very few make it to the beginning average nesting age of 25 years.
Citizen Science: The nest sitters
Sea turtles are much beloved and a source of pride for those who live on and visit the Outer Banks.
There is a huge cadre of volunteers who help them. North Carolina has one of the country’s largest network of volunteers. Some are stunned-turtle patrollers who in the winter rescue turtles that wash up suffering from hypothermia when the water temperatures dip below 52 degrees. See announcement at the end.
Other volunteers are nest sitters. On Ocracoke this summer, more than a dozen islanders attended a volunteer sea turtle nest watch training session by NPS biotechnicians Matt Janson and Ash Keiper-Kintz.
As the time approaches for hatching, approximately 60 days from the day the eggs are laid, the volunteers monitor an assigned nest and ensure that ORV activity does not impact sea turtle hatchlings by smoothing the deep tire ruts that can impede the hatchlings’ march to the sea.
If the “nest sitters” are fortunate, they will observe a “boil,” i.e., the sand moving as the hatchlings emerge. In those cases, the volunteers will escort them to the sometimes-perilous trek to the sea if ghost crabs and gulls are lurking.
Resource management staff train volunteers in the Seashore’s three districts to help monitor turtle nests in off-road vehicle areas that are within their hatch windows.
“We are grateful that this year we were able to expand our nest sitting volunteer numbers on Ocracoke,” Tongue said. “Previous seasons we have had only a couple volunteers assisting and this past season we had 20 volunteers on our roster that allowed 21 nests to be monitored in the evenings for hatch activity.”
This year, volunteers Susan and James Aiken received an award of volunteer excellence from Cape Hatteras National Seashore for their dedication to the Ocracoke sea turtle nest watch program.
A volunteer training session for those who want to help rescue cold-stunned turtles this winter will be held at 10 a.m. Dec. 3 in the Ocracoke Community Center.
Thank you for the wonderful work you do!
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