NewsNational News

Actions

Climate change tipping the gender balance of some species

Sea turtles are one of several species whose gender is determined by the temperature around the egg during incubation. Males are more likely to form during cooler temps and females during warm ones. Researchers are observing that hotter temperatures, due to climate change, are leading far more female than male sea turtles to hatch. In recent years, there have been no male hatchlings on a monitored, miles-long stretch of Florida beach.
Jeanette Wyneken, director of the marine science lab at Florida Atlantic University, has been studying sea turtle for more than 40 years. At the lab, she and a team are monitoring hatchlings from a nearby beach. She authored a groundbreaking study that found hotter temperatures, due to climate change, are leading to more female sea turtles hatching than male.
It’s not just sea turtles. Experts say most species of turtles, lizards and some other reptiles are also facing the same problem - a gender imbalance due to hotter temperatures impacting embryos during egg incubation.
Researchers in Florida carefully monitor sea turtle nests -- first trapping them and then releasing them into the ocean - to determine the gender ratio of hatchlings. Recently, there have been years when not a single male hatchling was found.
Posted at 3:47 PM, Jun 09, 2022
and last updated 2022-06-09 16:47:21-04

BOCA RATON, Fla. — For eight months out of the year, David Anderson patrols a several-mile long stretch of Florida coastline in Palm Beach County.

“Every morning at sunrise, we are on the beach,” he said.

Anderson and his team search for something amiss in the sand.

“It would be a very large, disturbed area,” he said.

That area is where a sea turtle laid her eggs.

“The odds are against them that when they come out of the nest, there's so many things that they could that can prevent them from getting out to the water and growing up to be an adult turtle,” said Anderson, who is the sea turtle conservation coordinator for the city of Boca Raton, Florida.

In recent years, researchers started noticing something strange about the sea turtle hatchlings.

“Some years, [there were] 100% female from some of our sample nests,” Anderson said. “There have been years where not a single male hatchling has been found.”

So, what’s going on?

Sea turtles are one of several species whose gender is determined by the temperature around the egg during incubation.

Males are more likely to form during cooler temps and females during warm ones.

Researchers have a catchy phrase for it.

“Hot chicks, cool dudes,” said Jeanette Wyneken, director of the marine science lab at Florida Atlantic University.

Wyneken studies sea turtles on the same stretch of beach monitored by David Anderson.

“There's no X chromosome or Y chromosome. There's just the environment directing the embryo to be male or female,” she explained. “And that particular part of that environment that matters is the temperature.”

Wyneken has studied sea turtles for 40 years and authored a groundbreaking study that found hotter temperatures, due to climate change, are leading to more female sea turtles hatching than males.

“The turtles that we bring in here are a sample of what's hatching on our beaches throughout the entire season,” she said. “And we're seeing more and more all-female years.”

It’s not just sea turtles.

Wyneken said most species of turtles, lizards and some other reptiles are also facing the same problem.

“If we're only making females, that's not going to pan out well in the future,” she said.

It is especially troublesome for species that are already endangered, like sea turtles.

Short of stopping climate change, though, there are a few things that can be done to try and restore the gender balance.

“Either watering nests to cool them down, or shading,” Wyneken said. “So, there's a suite of things that are being done elsewhere in the world that are not currently in practice here.”

Back on the beach, David Anderson and his team will continue working with researchers to monitor the nests and see whether any males hatch there.

“We do what we can to help sea turtles survive and reproduce,” he said, “and hopefully increase populations in the wild.”