Grounds crews eventually rounded up the wayward reptiles and deposited them back in the brackish water farther from airport property, but not before the incident disrupted JFK's flight schedule and contributed to delays that reached nearly 1 1/2 hours.
"Apparently, this is something the tower has experienced before," said Federal Aviation Administration spokesman Jim Peters. "I guess it's the season for spawning."
The invasion began unfolding, slowly, at around 8:30 a.m., when an American Eagle flight crew reported seeing three turtles while taxiing out for departure. Before long, a chorus of pilots was radioing the tower to report turtles either on the end of a runway that juts out into the water, or approaching on the grass.
The FAA halted flights for about 12 minutes shortly before 9 a.m. while some of the turtles were cleared away, then quit using the runway entirely after getting new reports of "massive numbers" of turtles on the tarmac, Peters said.
Port Authority of New York and New Jersey spokesman John Kelly said airport crews gathered up the turtles in about 35 minutes.
He identified the turtles as Diamondback terrapins, a species common to Jamaica Bay, which surrounds the airport. The turtles appeared to be about 8 inches long and weigh 2 to 3 pounds each.
Jets hit turtles a few times each year at JFK, usually in the final days of June or earliest days in July, according to the FAA's wildlife strike database. There have been no recent reports of the strikes causing any damage to an airplane.