New publication on marine Turtles!

Heredero Saura, L., Jáñez-Escalada, L., López Navas, J., Cordero, K. and Santidrian Tomillo, P. 2022 Nest-site selection influences offspring sex ratio in green turtles, a species with temperature-dependent sex determination. Climatic Change 170, 39 (2022). DOI: 10.1007/s10584-022-03325-y

 Abstract: 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. 

Photo from www.fisheries.noaa.gov

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.

 Press releases in Spanish here and here

 

 

MSc in Marine Ecology with the GEDA!

Margalida Castell Orell and Maria Martin Perez have sucessfully completed their Master on Marine Ecology at the University of the Balearic Islands. Maragalida and Maria did their final work within the GEDA on Storm Petrels and Cory's shearwaters, respectively. They both obtained the highest note. Congratulations! 

Master on Marine Ecology with the GEDA

M. Martin Perez

A. Sola

M. Martin Perez and M. Castell from the University of the Blearic Island, and A. Sola from the University of Santiago began their Final Work (TFM) for their Master Degree on Marine Ecology with the GEDA.

M. Castell

 Maria will be focussing her research on the response of Cory's Shearwater to climatic changes, Marga will experimentally evaluate the recruitment behaviour of Storm Petrel and Alfonso will study the foraging strategy of the Yellow-Legged Gull. They will be supervised by A. Sanz-Aguilar, G. Tavecchia and J.-M. Igual.
Their respective fieldwork campaigns are on the starting blocks !