Nest-site selection influences offspring sex ratio in green turtles, a species with temperature-dependent sex determination

Autor: L. Heredero Saura, L. Jáñez-Escalada, J. López Navas, K. Cordero, P. Santidrián Tomillo
Přispěvatelé: Conferencia de Rectores de las Universidades Españolas, Consejo Superior de Investigaciones Científicas (España), The Leatherback Trust, National Fish and Wildlife Foundation, European Commission, The Florida Aquarium, South Carolina Aquarium, Virginia Aquarium & Marine Science Center
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Climate change threatens species with temperature-dependent sex determination as further warming could result in extremely biased sex ratios or offspring of only one sex. Among the possible adaptations of sea turtles to climate change, are behavioral responses toward nesting in cooler areas. We analyzed nesting patterns of East Pacific green turtles (Chelonia mydas) in Costa Rica to determine the occurrence of nest-site selection and how this could influence primary sex ratios (PSR). Green turtles exhibited nest-site repeatability. Nests placed by the same individual were generally closer (mean distance: 237.4 m) than other nests on the beach (mean distance: 411.0 m) and this repeatability was maintained in different nesting seasons. Additionally, turtles tended to place late nests closer to each other than their early nests, suggesting an adjusting nesting behavior throughout the nesting season. A great majority of nests were placed in the vegetation (80.9%) and within this zone, turtles preferred nesting under trees (78%) than in grass areas (28%), where temperatures were cooler and PSR were less female biased. Mean nest temperature (°C) during the thermosensitive period and mean PSR were 30.7 ± 1.2 °C and 79 ± 4%, respectively. Most years were female-biased or extremely female-biased but there was approximately one male-biased year in the decade. Although many nests produced 100% females, some male hatchlings were produced every year, even during the extreme 2015–2016 El Niño event. The preference of green turtles for nesting in shaded areas could help to mitigate the negative impacts of climate change unless temperatures in shaded areas rose above the male producing temperatures.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Financial support for the research project at Cabuyal was provided over the years by The Leatherback Trust, the National Fish and Wildlife Foundation of the US, a Marie Curie Fellowship within the 7th European Community Framework Programme, the AZA Sea Turtle SAFE Program, the Florida Aquarium, the South Carolina Aquarium and the Virginia Aquarium.
Databáze: OpenAIRE