Marine Turtle Nesting on Hutchinson Island, Florida in 1971

Gallagher, Robert; Hollinger, Malcom; Ingle, Robert; Futch, Charles

Atlantic loggerhead turtle (Caretta caretta caretta) nesting was first noted 7 May, peaked during the first week of July and continued at least through 10 September; 1420 nests were recorded during this period. Forty-four percent (627) of the observed nests occurred during a four-week period ending 10 July. An increasing north to south nesting density necessitated a weighted estimate of the number of loggerhead nests on the island (N = 3350). Twenty-eight percent (395) of nests surveyed were destroyed by raccoons. Total egg production was estimated at 402,000. No linear relationship was discovered between carapace length and width from 164 tagged loggerhead turtles, nor was there a relationship between carapace width and crawl width. Seven turtles were observed to successfully build at least two nests. Time intervals between nestings ranged from 14 to 55 days and appeared to be multiples of 12 to 16 days, supporting the postulation of at least four nestings for two turtles. Distances between nesting crawls of tagged individuals ranged from 0.5 to 13.5 miles. Twenty-two Atlantic green turtle (Chelonia mydas mydas) nests (estimated 8-10 individuals and a total of 2948 eggs) were found only on two distinct sections of beach between 26 June and 30 August 1971. Two of four nesting green turtles were observed nesting a second time 14 days after tagging, 0.5 and 0.8 miles from original tagging sites. Mean width of the 22 green turtle crawls were significantly larger than mean crawl width of 153 tagged loggerhead turtles. Six leatherback turtle (Dermochelys coriacea coriacea) nests were encountered from 17 May to 30 June.