ESR 15:195-204 (2011)  -  DOI: https://doi.org/10.3354/esr00372

Sex ratios of leatherback turtles: hatchery translocation decreases metabolic heating and female bias

Annette E. Sieg1,*, Christopher A. Binckley2, Bryan P. Wallace3,4, Pilar Santidrián Tomillo5, Richard D. Reina6, Frank V. Paladino7, James R. Spotila5

1Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128-2406, USA
2Department of Biology, Arcadia University, 450 S. Easton Rd., Glenside, Pennsylvania 19038, USA
3Global Marine Division, Conservation International, 2011 Crystal Drive, Suite 500, Arlington, Virginia 22203-3709, USA
4Division of Marine Science and Conservation, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516-8648, USA
5Department of Biology, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104-2816, USA
6School of Biological Sciences, Monash University, Victoria 3800, Australia
7Department of Biology, Indiana-Purdue University, 2101 E. Coliseum Blvd., Ft. Wayne, Indiana 46805-1499, USA

ABSTRACT: Many sea turtle nesting colonies are in decline worldwide, and a common conservation practice maximizes hatchling production by translocating eggs from threatened nests to protective beach hatcheries. Typically, translocated eggs are ‘doomed’, or at risk of death due to tidal inundation, predation, or poaching. Sea turtles exhibit temperature-dependent sex determination. We determined how primary sex ratios, estimated from incubation temperatures, were affected by egg clutch translocation to a beach hatchery. We monitored incubation temperatures of eastern Pacific leatherback turtles Dermochelys coriacea in hatchery and in situ clutches at Playa Grande, Costa Rica, throughout each nesting season from 1998 to 2007. In situ clutches were estimated to be 90% female, whereas hatchery clutches (9% of clutches) were estimated to be 64% female. Taking into account differences in hatching success of in situ and hatchery nests, the overall sex ratio was 83% female. The Playa Grande hatchery abiotic environment (sand temperatures, water inputs) was similar to that in situ. However, metabolic heating was significantly reduced in hatchery clutches. The most likely explanation is that temperatures in hatchery clutches were cooler (less female-biased) due to decreases in the number of metabolizing embryos since hatchling success was lower in hatchery clutches than in situ clutches. Alteration of both primary sex ratios and hatching success is the tradeoff for reducing the risk of death to egg clutches by translocation to a hatchery. This tradeoff is not unique to Playa Grande leatherback turtles, and it is a strong indication that hatchery translocation should be used cautiously.


KEY WORDS: Dermochelys coriacea · Doomed-egg translocation · Hatchlings · Male production · Temperature-dependent sex determination


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Cite this article as: Sieg AE, Binckley CA, Wallace BP, Santidrián Tomillo P, Reina RD, Paladino FV, Spotila JR (2011) Sex ratios of leatherback turtles: hatchery translocation decreases metabolic heating and female bias. Endang Species Res 15:195-204. https://doi.org/10.3354/esr00372

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