Blog Post By: Chase, Sea Turtle Intern
If you’re familiar with the Edisto Beach State Park’s exciting Environmental Learning Center, you might be familiar with our two diamondback terrapins, Turnip and Rudy. Diamondback terrapins are a common species of turtle found all across the East Coast of the United States, from San Antonio to Massachusetts Bay. Unfortunately, due to human encounters, their population is now Threatened.
Their threatened status, however, does not stop some of them from living wonderful lives full of curiosity - and determination.
Terrapin turtles nest in a fairly similar manner to our sea turtles; the mothers come on land in the early months of summer searching for suitably sandy environments to lay their eggs as their sole motherly duty before disappearing into the water to continue their lives. This can be observed on our state park beachfront, where terrapin tracks and even nests can occasionally be found.
More surprisingly, though, this behaviour can also be observed on Runway 4L of JFK International Airport in metropolitan New York City.
Since as early as 2009, a runway at JFK International Airport has been consistently, annually invaded by a sea of diamondback terrapins seeking to nest in the sandy soil on the other side of the runway. In 2009, around 100 terrapins shut the whole runway down for nearly an hour and a half as crews raced to move the turtles from the runway and into suitable sand.
A year later, an even larger turtle army slowly heaved their way across the runway to lay their eggs. And again in 2011, even more turtles than before, again and again until 2013. The massive, ever-growing, yearly turtle invasions forced JFK International Airport to install a 4,000-foot long, 8-inch diameter plastic tube alongside the runway to serve as a barrier to keep the turtles from once again entering the runway.
It has not stopped them.
The team at JFK International reports a 50% decrease in turtle sightings and removals since the installation of the turtle wall. The native diamondback terrapins still come around every year - albeit in smaller numbers - just a little slower. They cannot climb the wall, but when the high tide rolls in, so do the turtles.
These events of mass turtle crawling have since become the focus of a team of wildlife biologists at the airport. Laura Francoeur, the chief wildlife biologist with the New York Port Authority, describes the issue as one of the most challenging issues her team has faced. They are seeking an explanation as to why the turtles keep coming back to the runway, no matter how many times they are removed, relocated, or even (very rarely) struck by planes.
Her team has one prevailing hypothesis: a massive decrease in raccoon population in 2008 may have caused many more terrapins than normal to hatch on the runway’s sand that year. This may have led to the large population numbers in recent years, as the young terrapins return to lay on the nesting grounds they were born upon. In contrast, as the raccoon population has bounced back, the terrapin population has decreased dramatically to an alarmingly low level because the raccoons eat 95% of their eggs. Ms. Francoeur’s team must now both protect the turtles from the dangers of the runway and the predation of the raccoons.
This lighthearted story of turtle-caused runway inconvenience makes for a fun but perplexing tale. The diamondback terrapins showcase the resilience of nature - the terrapins keep coming back to nest, year after year, no matter how much the humans move them or relocate them. Simultaneously, the turtles need the humans’ protection from the raccoons in order to keep nests safe and continue their population’s growth. Everything plays its part in nature, from the deadly raccoons to the fertile sand to our stalled planes. Finding our balance - that is the key to true sustainability.
Sea Turtle Biologist