AN EVALUATION OF NEST RELOCATION AS A LOGGERHEAD SEA TURTLE (Caretta caretta) MANAGEMENT TECHNIQUE IN NORTH CAROLINA

Abstract

A network of volunteers, under the guidance of the North Carolina Sea Turtle Protection Program, monitors and protects loggerhead nests laid on state beaches. Although volunteers are encouraged to allow nest incubation to proceed naturally and with minimal intervention, some volunteers will relocate freshly laid nests that are threatened by possible inundation by high tides, heavy beach traffic, or under a sloughing escarpment. Nest relocation may have negative effects: it may reduce hatching success, alter incubation duration, and reduce hatchling fitness. Thus an evaluation of hatching success and incubation duration at nesting areas under the protection of the NC Sea Turtle Protection Program is warranted. My objective for the evaluation was to use loggerhead sea turtle (Caretta caretta) nest activity data from four high-density North Carolina nesting areas – Bald Head Island, Cape Lookout National Seashore, Cape Hatteras National Seashore, and Topsail Island – to assess statistically the management technique of nest relocation in North Carolina. Using 1997 to 2001 data, provided by the North Carolina Sea Turtle Protection Program, I evaluated hatching success and incubation duration among in-situ nests, relocated nests, and in-situ nests affected by tidal inundation. During each of the five years, 1997 to 2001, the average number of nests moved on the study’s four North Carolina nesting areas approached 40 to 60 percent. The evaluation of hatching success showed a tendency of more loggerhead hatchlings hatching in in-situ nests than in relocated nests. Also, the evaluation indicated a tendency of in-situ nests having longer incubation durations than relocated nests. The evaluation showed relocated nests might have shorter incubation periods, and thus present nest relocation techniques in North Carolina might be skewing northern sub-population sexratios more in favor of female hatchling production. I formulated a series of nest relocation recommendations with the evaluation results: use nest relocation as a last resort, only relocate nests that will be over-washed daily by high tides, do not base nest relocation measures on previous summer storms, and do not relocate nests in heavy foot traffic areas.