Sand temperature decides whether a sea turtle hatches male or female. A 2018 study found 99.1% of young green turtles from warmer northern Great Barrier Reef beaches were female.

Of juvenile green turtles originating from warmer northern Great Barrier Reef nesting beaches, 99.1% were female, a 2018 study found.

Sand temperatures determine the sex of turtle hatchlings, with warmer temperatures resulting in more females, NOAA Fisheries says. Researchers from NOAA and Australia combined endocrinology and genetics to determine the sex of hundreds of green sea turtles on a Great Barrier Reef foraging ground, and traced which nesting beaches they came from.

Turtles from cooler southern nesting beaches were about 65 to 69 percent female. Of those from the warmer northern beaches, 86.8 percent of adults, 99.8 percent of sub-adults and 99.1 percent of juveniles were female.

Sand temperature decides whether a sea turtle hatches male or female. A 2018 study found 99.1% of young green turtles from warmer northern Great Barrier Reef beaches were female.

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