1996 Marine Turtle Nesting Report Ten Thousand Islands National Wildlife Refuge and Everglades National Park

Cheng, Ellen

This report summarizes sea turtle nesting activity on 8 islands (Brush, B, Turtle, Gullivan, White Horse, Hog, Panther, and Round Keys) in the Ten Thousand Islands National Wildlife Refuge and 4 islands in Everglades National Park (Tiger, Picnic, Indian, and Kingston Keys). Raccoons, a major predator of turtle eggs and hatchlings, were trapped on some of the islands prior to the nesting season to see if any changes in depredation would occur. The report contains information on the number of nests, number of false crawls (aborted nesting attempts), depredation rates, and hatch success rates. Graphs, maps, and tables present the data. Author Abstract: We surveyed eight islands within or near the future Ten Thousand Islands National Wildlife Refuge (TTINWR) and four islands of the adjacent Everglades National Park (ENP) for sea turtle nesting activity. Raccoon control was conducted on two TTINWR islands prior to turtle nesting season to assess effects on nest success. Our results showed raccoon depredation to be a major factor influencing nest success in the Ten Thousand Islands. The depredation rate was significantly lower for TTINWR islands than for ENP islands (49.7%, n=195, for TTINWR; 79.5%, n=73, for ENP). This may be due to TTINWR' s efforts at raccoon elimination this year. In all other respects, our data showed turtle nesting activity to be consistent between park and refuge islands. For TTINWR, we recorded 422 turtle emergences, 52.4% ofwhich were false crawls. Overall nest density was 30.9 nests/ km. Both loggerhead sea turtles and a small number of green sea turtles nested on these islands. For ENP, false crawls ·made up 48.6% of recorded turtle emergences (n=144). Overall nest density was 29.2 nests/km. No green sea turtles were found on ENP islands.