Do sea turtles know something we don’t about what may be coming in the height of the current hurricane season?
Amateur paleontologists in Colombia in 2015 found fossils of one ancient ancestor of today’s sea turtles dating back 120 million years to a time when dinosaurs roamed the Earth. So the idea that these mysterious, awe-inspiring, primordial creatures have adapted their nesting behavior to avoid extinction is not a huge stretch of the imagination.
When residents near Aquarina Beach and Country Club, half a dozen miles north of the Sebastian Inlet, began seeing huge sea turtles tearing up the dunes and uprooting carefully planted rows of sea oats behind oceanfront homes, they wondered what was going on. Old wives’ tales say the turtles somehow sense when a hurricane is on the way and lay their precious eggs way high up in the dunes to protect their progeny from being washed away.
The truth, according to scientists, is almost as fascinating as the lore.
Two things we know: This bizarre activity occurs in late July and August – which also happens to be when hurricane season kicks into full swing – and the oddity doesn’t happen every year.
The reason the turtles’ current dune-wrecking stands out to locals is because it’s different from the beach nesting typically seen in the late spring or early summer.
Celeste McWilliams, a certified sea turtle educator who runs the school programs at the Barrier Island Center, had some perfectly good explanations.
The turtles who mate in the spring and enjoy their peak nesting season earlier in the summer are loggerheads, McWilliams said. Many of the loggerhead hatchlings have already sprung from their shells and started their own amazing journeys into the sea. And though they still participate in the land grab for a protected spot, the loggerheads are not the aggressive dune-wreckers. Instead, green sea turtles are the culprits.
“Greens are in the prime of their nesting season right now,” McWilliams said, adding that the Archie Carr National Wildlife Refuge – which encompasses 20.5 miles of beach from about Coconut Point Park in Melbourne Beach to just south of Golden Sands Park near Windsor in Indian River County – has seen more than 200 new nests laid every single night the past week or so.
“In the seven days prior to Thursday, August 11, we had 1,830 nests counted in the refuge,” McWilliams said.
“And though all sea turtles go as far up the beach as they can to lay their eggs, the green sea turtles are known for going up onto the dunes more than the loggerheads.” she said.
McWilliams said there’s a nest about every four and a half linear feet throughout the refuge right now. From a logistical standpoint, that’s pretty crowded, and the green sea turtles showing up late to the party are being both savvy and considerate as they head higher up into the dunes where they can stake their claim without inadvertently digging up a sister turtle’s nest.
The greens are the largest species of hard-back turtles, with adults growing to about 3-feet long and weighing up to 350 pounds, so they come in like a wrecking ball and don’t really care that those sprigs of sea oats were placed there by humans to help stabilize the dune. Their eggs must survive for the next two treacherous months of hurricane season before they are ready to hatch.
So, did the green sea turtles learn by trial and error to “go deep” into the end zone to build their nests? Anything is possible over 120 million years.
What about the fact that it doesn’t happen every year? “We only get the green sea turtles every other year, their nesting is cyclical, so they come back in two-year cycles,” McWilliams said.
Even stranger than the dune-chewing green turtles, McWilliams said, is the fact that a hawksbill sea turtle nested just north of the Sebastian Inlet last Thursday. That species is common in the Caribbean, but usually only seen as far north as Fort Lauderdale, she said. “The rangers from the Brevard County side of the Inlet saw it just before 8 a.m. and we able to get down there and take DNA samples.”
When asked if the hawksbill turtle maybe got confused and thought she was in Fort Lauderdale because it’s been so hot here, McWilliams said there’s probably no connection with the record-breaking weather – even though temperatures this summer, starting as early as May, have been hotter than recorded in more than 120 years.