Rare leatherback sea turtle spotted nesting on Sanibel

Karl Schneider
Fort Myers News-Press

Sea turtle nest monitors along the Sanibel and Captiva beaches happened upon a rare sighting during a nighttime survey Sunday night.

Workers with the Sanibel-Captiva Conservation Foundation spotted the tracks of a rare leatherback sea turtle but did not see signs of a nest. Later that night, however, they came across the giant leatherback turtle on shore laying its clutch.

“Leatherbacks are an endangered species, so spotting one is always a unique experience,” Kelly Sloan, the foundation's coastal wildlife director and sea turtle program coordinator wrote in an email. “In Florida, they nest much more commonly on the Atlantic coast. Leatherbacks are considered a rare species on the Gulf coast.”

A nesting leatherback sea turtle was spotted during a Sanibel-Captiva Conservation Foundation nesting survey Sunday, May 11, 2020.

About 50% of leatherback nests found in Florida are in Palm Beach County, according to the Florida Fish and Wildlife Conservation Commission.

Since 2015, FWC’s Fish and Wildlife Research Institute has recorded only one other leatherback nest in Lee County. Last year, 1,105 leatherback nests were documented throughout the state. So far this year, the foundation has documented two leatherback nests.

The foundation posted photos of the leatherback on its Instagram page after the rare sighting.

"We have some incredibly exciting news to share with you all," the post says. "For the first time in SCCF history, a nesting leatherback was encountered during our nighttime surveys!! ... A new turtle to our beaches, we named her "Juniper." We are very hopeful this isn't the last time we will get to see her this season!"

Adult leatherbacks can reach sizes of 8 feet and weigh between 700 and 2,000 pounds. Jack Brzoza, a biologist with SCCF, wrote in an email that they measured the leatherback they came across Sunday night had a carapace at just about 5 feet long. Accounting for her head and neck, she was likely about 6 feet long, he wrote.

Early nesting:Early sea turtle nesting season could be result of warmer Gulf waters

The leatherback nesting season runs between March and July in Florida, and Brzoza wrote that SCCF’s first leatherback nest was found April 1.

“Most leatherbacks re-migrate to their nesting beaches every 2-3 years, so she likely won't return next season,” Sloan wrote. “From what I understand, leatherbacks show less nest-site fidelity than other species of sea turtles. Again, we don't have enough data on our beaches to draw any conclusions regarding site fidelity.”

Because of the rare nesting habits on the west coast of the state, finding two in a season is unique.

“We had been hopeful, with some of the leatherback activity we had seen on our beaches earlier this season, that she would return and that we would be able to encounter her,” Brzoza wrote. “We were relieved and incredibly excited when we finally found her!”

Sloan said that the U.S. Fish and Wildlife Service believes leatherback clutches average between 80 to 85 yolked eggs.

"Because they don't nest commonly on our islands, our sample size is small and we don't have a good estimate for average clutch size on our beaches." Sloan said. 

The foundation publishes online the sea turtle nests its surveyors find on Captiva and Sanibel islands.

More:Sea turtle nesting season starts soon on quieter beaches

A nesting leatherback sea turtle was spotted during a Sanibel-Captiva Conservation Foundation nesting survey Sunday, May 11, 2020.

Various sea turtles were reportedly nesting earlier than usual this year, as some experts thought the warmer sea surface temperatures prompted the turtles to carry clutches ashore.

Charles Gunnels, associate professor of animal behavior at Florida Gulf Coast University, thinks the warm temperatures aren’t necessarily bad if sea turtles respond in kind by nesting earlier.

"If air and sea temperatures go up, an early season might be good because sea turtles are responding to environmental conditions and changing nesting," Gunnels said. "They have both female and male nestlings. In some ways, I might be more concerned if they're not nesting, but we're seeing temperatures increasing." 

The first known leatherback nest in Collier was recorded on Keewaydin Island in 2015.

“That is the first time we know of one in Collier County,” Dave Addison, senior biologist at the Conservancy of Southwest Florida told the Naples Daily News. “It is the first time we documented one. In 1947 there was a guy out on the beach with his father and they said they found one, but it wasn’t documented.”

Collier County's Principal Environmental Specialist Maura Kraus' latest weekly report lists 104 total nests in the county, nearly 30 more than this time last year.

Karl Schneider is an environment reporter. Follow him on Facebook and Twitter: @karlstartswithk, email him at kschneider@gannett.com

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