Comparing the effect of temperature on the duration of the interesting interval across multiple sea turtle species

NATHAN ROBINSON; GABRIELA S. BLANCO; CHELSEA CLYDE-BROCKWAY; JACOB HILL ; SAMIR PATEL ; PILAR SANTIDRIÁN TOMILLO; CASSONDRA WILLIAMS; JAMES R. SPOTILA; FRANK V. PALADINO

Las Vegas

Congreso; 37th Annual Symposium on Sea Turtle Biology and Conservation; 2017

Sea turtles often exhibit dramatic responses, both behavioural and physiological, to variations in external temperature. For example, previous studies have shown that external temperature is strongly correlated to the duration of inter-nesting period in both loggerhead Caretta caretta and green Chelonia mydas turtles. Specifically, as temperatures increase the duration of the inter-nesting interval decreases, presumably because the rate of pre-ovipostional eggs development is increased at higher temperatures. Yet, uniquely among sea turtles, the leatherback Dermochelys coriacea is able to maintain body temperatures significantly elevated about external conditions though gigantothermy. As such, we predict the duration of the inter-nesting interval in leatherback turtles would not be affected by variation in water temperature as it is with other sea turtle species. To test this, we deployed data-loggers, with the capacity to record temperature at intervals less than 1 min, onto inter-nesting leatherback, green, and hawksbill turtles Eretmochelys imbricata. As expected, higher temperatures lead to shorter inter-nesting intervals in green, and hawksbill turtles, but was not so for leatherback turtles. Interestingly, this means that under warmer conditions, non-leatherback sea turtles would have shorter inter-nesting intervals and thus remain at the nesting location for shorter periods of time. In contrast, leatherback turtles would be expected to remain at the nesting habitats for similar lengths of time regardless of temperatures. This has implications for how nesting phenology will vary between sea turtle species in response to climate change and explains why local temperature variation has not been linked to nesting phenology in leatherback turtles as it has in the other sea turtle species.