Every year in Florida, millions of baby sea turtles scramble across the sand from their nests to the ocean. Recently, almost all of these baby turtles have been female.
Wyneken: “When an egg is laid, there’s no x and y chromosome. The sex of the embryo, which means the sex of the hatchling, is determined by the conditions in the nest.”
Jeanette Wyneken of Florida Atlantic University says temperature is the number one factor determining the sex of sea turtles. The hotter the sand, the more likely it is that turtles will be female.
Wyneken has been studying loggerhead turtles in Florida for more than a dozen years. Over this time, males have been rare. And over the past three years, her team has found only females.
Wyneken: “We’re just never seeing enough time spent by those eggs at lower temperatures. The nests get warm right away, and they stay warm, and we get all females.”
Sea turtles live for several decades. So for now, there are still enough mature males for breeding. But if the trend continues, the next generation could struggle to reproduce. Wyneken says the message is clear.
Wyneken: “The environment is getting warmer, and it has consequences.”
Reporting credit: Mark Knapp/ChavoBart Digital Media.
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