When considering our state reptile, the loggerhead sea turtle, it is hard for me to know where to begin. Believe it or not, loggerheads bookended my zoo career.
My Riverbanks career began with the promise of a job in January 1973. However, I had graduated from Clemson the previous summer and needed something to do in the interim. The zoo’s first director, John Mehrtens, a reptile enthusiast, was involved in one of the original efforts to save these magnificent creatures. He asked if I would like to participate in a program that was then being conducted on Fripp Island in Beaufort County. I knew nothing about sea turtles or Fripp Island, but the offer to live on the coast after four years of college was irresistible. And they would pay me $25 a week! Within days, I found myself checking into a room in the old Fripp Island Inn.
That initial effort was known as a “head start” program. It involved collecting baby turtles as soon as they hatched, raising them in tanks to a certain size and then releasing them into the Gulf Stream. It was thought that by capturing the baby turtles during their most vulnerable time, they could be given a head start to maturity. A colleague and I walked the beach before dawn each morning searching for hatchlings. These were collected and taken to two large, round tanks near the inlet. We fed them a diet of ground fish and, when they reached salad plate size, turned them over to the SCDNR for release. Our little program began and ended that same year when the head start model was abandoned as being far too labor intensive with minimal return.
Fast forward nearly 40 years. My wife, Becky, and I purchased a home on Kiawah Island in 2008 in preparation for our retirement. Soon after, she began volunteering for the Kiawah Island Turtle Patrol. Kiawah is a vital nesting ground for loggerhead turtles. Female loggerheads do not reach sexual maturity until 12 to 30 years of age. Every two to three years a female will join with thousands of others to mate in coastal waters and then return to nest near the beach where she was hatched (they do not necessarily return to the exact same beach; some return many miles away).
From May to October each year, eight teams cover the entire length of the 10-mile long beach in search of nests. The 350-pound females dig an 18- to 20-inch deep nest where 100 to 150 pingpong ball-shaped eggs are deposited. The entire nesting process takes place at night in a little over an hour. Females typically lay several nests each season, approximately two weeks apart. Nests are fairly easy to find due to the distinct impressions left by incoming and outgoing females. When a nest is discovered in a risky location, the volunteers relocate the eggs to a safer spot, marked with a PVC pipe and flag. The entire nest hatches at once after an incubation period of 55 to 60 days, typically at night, and the baby turtles scurry up out of the nest in unison (known as a “boil”) and crawl to the surf. During their brief journey to the sea, they are subject to predation by gulls, raccoons, and ghost crabs. The 2020 Kiawah nesting season resulted in 342 nests out of 5,552 loggerheads nests along the South Carolina coast.
Why have efforts to save loggerheads persisted over the past 50 years? In short, they are among the most interesting animals on earth. Loggerheads have been around for almost 40 million years and can be found throughout the world’s oceans. They are one of seven sea turtle species and are second in size to the leatherback. The worldwide population of loggerheads is unknown, although most populations outside the United States are in decline and considered threatened. Loggerheads have a lifespan of 45 to 67 years.
Perhaps the most fascinating part of the Atlantic loggerhead’s life is its migration pattern. If a hatchling is lucky enough to reach the Gulf Stream, it begins an 8,000-mile clockwise journey using magnetic cues around the North Atlantic gyre. During this time, they eat a diet of crabs, mollusks, shrimp, jellyfish, and vegetation. Incredibly, they do not return to the coastal waters of North America until 6 to 12 years later! Their journey is among the longest migrations in the animal kingdom. Given their size, it’s not surprising that most young turtles fail to survive the initial journey. Few survive to adulthood, with estimates ranging from one in 1,000 to one in 10,000.
The facts contained in this article only scratch the surface of sea turtle biology. I would encourage those interested to take the time to study these fascinating animals in more detail.