How do sea turtles hatch?

Natural History

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Watch sea turtle hatchlings journey to the ocean during the 2013 nesting season in Dry Tortugas National Park, Florida. This video was captured by a National Park Service professional. Please stay clear of nesting sea turtles and hatchlings, which are protected by law on all U.S. shores.

In summertime when the weather is warm, pregnant female sea turtles return to the beaches where they themselves hatched years before. They swim through the crashing surf and crawl up the beach searching for a nesting spot above the high water mark. Using her back flippers, the reptile digs a nest in the sand. Digging the nest and laying her eggs usually takes from one to three hours, after which the mother turtle slowly drags herself back to the ocean. 

The sea turtle lays up to 100 eggs, which incubate in the warm sand for about 60 days. The temperature of the sand determines the genders of baby sea turtles, with cooler sand producing more males and warmer sand producing more females. The phenomenon is called Temperature-Dependent Sex Determination, or TSD, and governs the genders of other reptiles, too, including alligators and crocodiles. Current NOAA research suggests that warming trends due to climate change may cause a higher ratio of female sea turtles, potentially affecting genetic diversity.

When the tiny turtles are ready to hatch out, they do so virtually in unison, creating a scene in the sandy nest that is reminiscent of a pot of boiling water. In some areas, these events go by the colloquial term "turtle boils." Once hatched, the turtles find their way to the ocean via the downward slope of the beach and the reflections of the moon and stars on the water. Hatching and moving to the sea all at the same time help the little critters overwhelm waiting predators, which include sea birds, foxes, raccoons, and wild dogs. Those that make it through the gauntlet swim to offshore sargassum floats where they will spend their early years mostly hiding and growing.

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