The Nest Environment and the Embryonic Development of Sea Turtles

Sea turtle eggs are deposited in a large clutch in a nest excavated by the female in sandy marine beaches. Incubation requires several months during which time the sea turtle embryo grows from a few cells to a fully formed organism capable of independent existence. A microclimate suitable for incubation is generated by interaction among the physical characteristics of the material composing the beach, the physical structure of the beach, local climate, and the eggs in the clutch. This chapter focuses on the environment for incubation and on conceptual ways of examining and describing it while pointing out remaining issues. Reptile embryos develop successfully over a range of temperatures. Typically, incubation period decreases as incubation temperatures increases. The thermal tolerance range (TTR) for development of sea turtle embryos incubated at constant temperature appears to fall between about 25 to 27°C and 33 to 35°C and is around 10°C wide.