Paul Hillbrand, STPP Coordinator & Beth Darrow, Senior Scientist
The Bald Head Island Conservancy (BHIC) Sea Turtle Protection Program (STPP) successfully conducted the 2019 annual sea turtle saturation tagging and monitoring program during a record-breaking year full of both successes and challenges.
A total of 437 nesting activities were observed during the 2019 season, including 170 confirmed loggerhead (C aretta caretta) nests and 267 false crawls. This was the largest number of sea turtle nests documented in our patrol area since our program began in 1983. A total of 83 uniquely identified female loggerhead sea turtles were encountered this season, of which approximately 26% were returnees and 74% were new females to BHI beaches. This is a very large proportion of new females to BHI.
The large amount of nesting activity this season provided exciting experiences for our sea turtle team, and plenty of opportunities for the public to personally encounter a sea turtle, but also a number of challenges. The sea turtle team conducted nightly patrols seven nights a week from May 18 to September 3 for a total of 108 nights, and was assisted by dozens of volunteer nest monitors working at hatchings and excavations. Each nest was caged to exclude predators, but many more cages needed to be constructed. Forty-five imperiled nests were relocated within the BHIC patrol boundaries due to locations too close to the tide. Ten nests were confirmed lost to high astronomical tides or Hurricane Dorian, with potential for 20-25 more.
Finally, for the first time at this scale, coyotes began predating on the sea turtle nests of BHI, despite caging and full night patrols. To date, 57 of the 170 nests were depredated, with an average of 2 depredation attempts per night. An estimated 2,088 eggs were lost to coyote depredation (12% of the total eggs). We estimate at least 2-4 hours each night (~276 person-hours from June 1 st to August 31st) were used specifically to patrol for coyotes, repair cages, attempt to rescue eggs and hatchlings, and apply extra fortification to each cage on the beach. Our regular summer spotlight surveys have seen a 4x increase in coyote sightings throughout the island compared to 2018, so we suspect the coyote population is growing, and individual coyotes have developed behaviors to navigate sea turtle nest cages (chewing, digging, and tunneling).
You can read about the Village of BHI's Coyote Management plan here: http://bit.ly/BHIcoyotes
Despite these challenges, the sea turtles of BHI were very productive this year. To date, 140 of 170 confirmed nests have been excavated with hatch success of 67% and emergence success of 63%. All confirmed nests produced an estimated 12,500 turtle eggs laid with roughly 8,000 hatchlings produced.
Our total nest success numbers will be finalized in the next month or two, and we will have more information on the number of new nesting females after genetic samples have been analyzed by our colleagues at the University of Georgia.
We would like to thank our tireless interns, volunteers, and donors for all their assistance in making this a successful sea turtle nesting season.