COMPARISONS OF LETHAL AND NONLETHAL TECHNIQUES TO REDUCE RACCOON DEPREDATION OF SEA-TURTLE NESTS

Depredation of sea turtle nests by raccoons (Procyon lotor) can hinder management attempts to increase recruitment of turtle hatchlings. We tested 3 techniques for their effectiveness in reducing raccoon predat ion on turtle nests. During 1993-91, direct comparisons of lethal remo val, nonlethal conditioned taste aversion (CTA), and nest screening we re conducted at Canaveral National Seashore (CNS), Florida. Lethal rem oval of 215 raccoons. at a level of about 50% of the population using the barrier beach, was not effective at reducing nest depredation. Non lethal use of estrogen-laced eggs to induce conditioned taste aversion had Ilo significant effect on nest depredation rate. Nest screening w as the only treatment that significantly reduced nest depredation. Nes t screening was labor-intensive and more expensive than lethal lethal removal and CTA, hut maintained raccoons as part of the coastal ecosys tem while affording protection to sea turtle nests.