Grant: 23-019R
Project Title: Investigating clutch frequency and inter-nesting habitat for a globally important loggerhead rookery: Year 4
Project Manager: Sarah Hirsch and Dr. Justin Perrault
Organization: Loggerhead Marinelife Center (Non-Profit Organization)
Grant Amount: $35,910.00
Completion Date: 2024-04-04
Summary: Southeastern Florida is a critical breeding ground for loggerhead sea turtles (Caretta caretta). While nest counts reveal that Palm Beach County hosts the highest density of loggerhead nesting in the state of Florida, little research has evaluated key life-history traits and habitat use of breeding loggerheads in this area. Clutch frequency refers to the number of nests a female sea turtle deposits within one breeding season and serves as a key measure of a female's total reproductive output. This study aims to provide an accurate clutch frequency estimate for these animals by satellite tracking nesting loggerheads from their first nest of the season. Additionally, nest site fidelity and inter-nesting home-range estimates will be evaluated to understand the space use of breeding loggerheads in southeastern Florida. Elucidating in-water hotspots is imperative for developing effective conservation strategies aimed at loggerhead population recovery. Finally, females will be tracked back to their foraging grounds, allowing for comparisons of potential carry-over effects on reproductive output.
Results: Eleven nesting loggerhead turtles were outfitted with Wildlife Computers SPLASH satellite transmitters (7 tags purchased with funds from this grant) in April 2023 after nesting on Juno and Jupiter Beaches. All transmitters were deployed on the first loggerhead females to show up on the nesting beaches to ensure that females were tagged on their first nest of the season. Two of the turtles satellite tagged had existing flipper and PIT tags and had a known history. Of the eleven turtles, we were able to re-encounter six of them ranging from three to eight encounters (nests and false crawls). Clutch frequency was 6.4 nests (range 5-7 nests). All eleven turtles have departed for and reached their foraging grounds. Tracking duration lasted from 154 to over 340 days, with six tags still transmitting as of March 19, 2024.