Laura SivessPhD studentEmail: l.a.s.sivess@qmul.ac.ukProfileProfileProject title: Evaluating the effect of temporal and spatial change in a species with temperature dependent sex determination: from primary to operational sex ratio Summary: Reproduction is essential for the continuation and success of all species. Understanding the behaviours and mechanisms which facilitate reproduction provides information on how populations may respond to environmental change. This is particularly important in species with temperature-dependent sex determination, as the sex of offspring is determined by environmental conditions. During this project, I will investigate how the operational sex ratio (OSR) of loggerhead sea turtles (Caretta caretta) changes throughout the mating season, determining the impact of polyandrous mating systems on the rate of multiple paternity across the archipelago of Cape Verde. Specifically, I will i) describe changes in the adult sex ratio and OSR using unmanned aerial vehicles (UAVs) within and between breeding seasons, ii) determine the rate of multiple paternity in clutches using microsatellite analysis iii) describe the cost-benefit balance of polyandry vs monandry using a largescale hatchery, iv) determine the correlation between primary and operational sex ratio. Supervisors Dr Gail Schofield Professor Christophe Eizaguirre Research