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Mostly female turtles born due to climate change

TurtlesImage source, Getty Images
Image caption,

Loggerhead turtles are mostly being born female

Turtles in Florida, in the US, are mostly being born female and it is mainly due to climate change.

Scientists say the gender imbalance of Florida's sea turtles has been made worse by hotter summers.

The sex of sea turtles - along with a couple of other species like crocodiles - is dependent on the temperature of the egg.

Recent heatwaves have caused the sand to get so hot that almost every turtle has been born female.

Media caption,

Climate change: How warmer sands are affecting green sea turtles

"Scientists that are studying sea turtle hatchlings and eggs have found no boy sea turtles, so only female sea turtles for the past four years," said Bette Zirkelbach, manager of the Turtle Hospital in Marathon, a city in the Florida Keys.

The sex of sea turtles and alligators depends on the temperature of developing eggs.

When a female turtle digs a nest on a beach, the temperature of the sand will decide whether the baby is a male or female.

If a turtle's eggs incubate below 27.7 Celsius, the turtle hatchlings will be male, whereas if they incubate above 31C, they will be female, according to NOAA'S National Ocean Service website.

The frightening thing is the last four summers in Florida have been the hottest summers on record

— Bette Zirkelbach, Manager, Turtle Hospital

With temperatures rising because of climate change this could affect the number of sea turtles there are.

"Over the years, you're going to see a sharp decline in their population because we just don't have the genetic diversity," said Melissa Rosales Rodriguez, a sea turtle keeper at the recently opened turtle hospital at the Miami Zoo.

"We don't have the male-to-female ratio needed in order to be able to have successful breeding sessions."