The shores of Cape Lookout National Seashore are perfect nesting grounds for Loggerheads and other sea turtles. This video explores the life history of these extraordinary creatures of the sea.
- Credit / Author:
- Cape Lookout National Seashore
- Date created:
- 2010-11-13
Summer at Cape Lookout National Seashore brings warm weather, fresh seafood, and well deserved vacations. It also marks the beginning of nesting season in the park. Many birds and turtles migrate to or through the coast of North Carolina to build nests and lay eggs.
Cape Lookout is one of the last nesting grounds available to several endangered and threatened species, including the Loggerhead sea turtle.
There are six species of sea turtles that can be found in the United States. Hawksbill sea turtles often nest in Florida and the U.S. Caribbean. The Olive Ridley does not nest in the U.S., but does feed along the southwestern coast.
Cape Lookout National Seashore protects the nesting and feeding grounds for the other four species of sea turtles. Kemp’s Ridley and Green turtles can be found in the waters around the park, but they rarely nest here. Leatherback turtles have been known to nest here occasionally, but only Loggerhead turtles regularly nest in this park.
Park staff and volunteers from the Student Conservation Association search the 56 miles of beach in Cape Lookout from May to September for signs of sea turtle nesting.
The easiest way to spot a nest is to find a crawl. A crawl is what we call the tracks in the sand made by a female sea turtle as she crawls on to the beach, lays her eggs, and crawls back into the ocean.
Did You Know?: Unlike people, sea turtles have to think to breathe. They do not take breaths automatically. This turtle is lifting her head to breathe just like she would do if she was in the water.
The park checks for these signs daily because the turtles usually lay their eggs at night and the tides and winds can smooth away the tracks in a couple of days. Nests without crawls are much harder to see because they look a lot like the rest of the beach.
Each clutch, or group of eggs, that is found is marked with white PVC pipes and then numbered and measured. A wire grate is placed over the nest as an EX-closure to keep out predators which like to dig up and eat the eggs. The distance to the high tide line and to the storm tide line is also measured. If the nest is below the high tide line or the storm tide line, it may be relocated to a safer spot.
The shape and size of the eggs in the nest indicates which type of turtle they belong to. This egg is about the size of a ping pong ball, but is soft and leathery and may have a few small dimples on the side. It is from a Loggerhead Sea Turtle.
Leatherback eggs are slightly larger and their nests also contain smaller yokeless eggs, called “spacer eggs.” These spacer eggs do not contain turtles. Their job is to cushion the large eggs from the weight of the sand and from the weight of each other.
As part of a three year research study at Cape Lookout, one egg is taken out of the nest and given a DNA test. This is how the park tracks which nests from this year have the same mother and helps the park identify if this female might have laid nests in other years.
The loggerhead eggs incubate for an average of 60 days before they hatch at night. The baby sea turtles, called hatchlings, follow the light of the moon and the stars on a mad dash to the ocean. This is why many coastal areas have restrictions on lights along the beach in the months that turtles are hatching to keep from confusing the turtles. This is not a problem at Cape Lookout, because the islands in this park are undeveloped.
But, the beach is still full of danger for a newly hatched turtle. Nests tend to be about 15 feet from the high tide line. This means that even if the tide is at its highest, a little two inch long hatchling will have to crawl a distance 90 times its size. For a person, that would be a distance of about 500 feet: which is a little more than 3 times the height of the Cape Lookout lighthouse. The turtles must avoid the seagulls, raccoons and other predators which like to eat hatchlings on their way to the water.
Park staff close off the beach in front of a nest about two weeks before it is due to hatch. This gives the wind and waves enough time to smooth away the tire tracks on the beach so the turtle hatchlings will not get trapped as they head towards the ocean. A tire track may not seem that dangerous, but these ruts would appear to be about 5 feet deep and 10 feet wide for a person. A tiny turtle can get trapped in the ruts and get eaten by predators or die from the heat of the sun the next day.
After the turtles hatch, park workers dig up the nest to count the clutch. This clutch has 99 eggs that hatched, 4 eggs that did not, and one hatchling that didn’t make it out of the nest. While most of the eggs will hatch, it is estimated that only about 70% of the hatchlings will make it to the ocean.
Once they make it to the ocean, the hatchlings are still not safe. Many sea creatures like to snack on sea turtle hatchlings. Sharks and other fish catch them from the water and gulls and pelicans dive and catch them from the air.
To survive all the predators they face they have to grow very quickly. This little 2 inch turtle will grow to 10 times that size in only 8 months. By the time it becomes a full grown adult, its shell will be about 3 ½ feet long. Adult loggerheads can weigh anywhere from 150 to 400 pounds: that’s as much as an oven and a refrigerator combined!
Those turtles that make it out beyond the coastal waters will spend the next 3 to 7 years out at sea. We don’t really know what happens to the turtles during this time. A few turtles of this age have been found floating in sargassum and other sea grasses in the Sargasso Sea, but they are difficult to find and almost impossible to track with the current techniques. That’s why these years are called the Lost Years.
After the Lost Years, sea turtles migrate back to the inner coastal waters. Here, their major causes of death are from human action. Trash floating in the sea getting mistaken for food, boat propellers striking their backs, and fishing nets trapping the turtles are major concerns for all coastal areas where sea turtles live.
Although they are large animals, sea turtles are not fearsome predators. They are much too slow to catch many other sea creatures. A loggerhead’s diet is made primarily of mollusks and crustaceans, but they will also eat jellyfish and any fish swimming slowly enough for them to catch. Sea turtles do not have any teeth; they simply crush their food with their powerful jaws.
All of the sea turtles in the United States are endangered or threatened with extinction. This is partially because only 1 out of every 500 eggs will hatch and survive to adulthood. This is why it is so important for park visitors, volunteers, and staff to work to protect these magnificent creatures.
