Nest-site selection by the loggerhead sea turtle in Florida's Ten ThousandIslands

Loggerhead sea turtles (Caretta caretta) nest in numerous substrate and bea ch types within the Ten Thousand Islands (TTI) of southwest Florida. Nest-s ite selection was analyzed on 12 islands within this archipelago. Physical characteristics of beaches were recorded to identify the relatedness of the se variables and to determine their importance for nest-site selection in C . caretta. These characteristics included ordinal aspect, beach length heig ht of canopy, beach width, overall slope (beach slope and slope of offshore approach), and sand samples analyzed far pH, water content, organic conten t, shelliness (% of calcium carbonate content), and particle size (8 size c lasses). AII physical variables, as well as nesting densities and locations , were included in a tree regression model to examine nest-site selection. In the TTI, loggerheads use wide beaches (>8.5 m) that inherently have less slope and, secondarily wide beaches that have less shells (low amounts of calcium carbonate; >8.5 m) in the nesting substrate In addition, C. caretta nest sites were located within or in close proximity to the supra-littoral vegetation zone of beaches in the TTI.