Research Project
Full description At a nesting rookery in the northern Great Barrier Reef, Australia, we used data loggers to examine the impact of heavy rainfall and shade on the nest temperatures for green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles clutches, which have temperature-dependent sex determination. In the middle of the nesting season (December-March), on 21 January 2019, 125 mm of rain fell over two days, causing nest temperatures to initially decrease, falling well into the male-producing range for sex determination. This was profoundly cooler than the average nest temperatures of clutches without shade and prior to the heavy rainfall. Extreme rainfall events are predicted to increase around Australia due to climate change but may help counteract impacts of atmospheric warming on sea turtle offspring sex-ratios. Our results also show the potential for artificially cooling nests by applying a combination of shade and irrigation, to counter the expected increases in the feminisation of sea turtle hatchling production worldwide.