D-I-Y Hatching

Sea turtles have a problem: It’s too hot.

For these migratory creatures, rising global temperatures means that their nests are hotter. Because the temperatures of their homes determine their offspring’s sex, that means they are producing more females.

That’s not necessarily a bad thing, per se, however, the rising temperatures also mean that fewer baby turtles will survive, which endangers the species, researchers say.

Now, turtles are trying to solve this problem themselves, according to a new study.

“Coming ashore onto a beach (often the beach from where they hatched), sea turtles use their flippers to carefully scoop out the sand and create flask-shaped nests in the sand in which they lay their eggs,” wrote Mollie Rickwood, Annette Broderick and Robin Snape, researchers involved in the study, in an article for the Conversation. “There is no maternal care for these nests – their success depends solely on the environment.”

Researchers who have been monitoring green and loggerhead turtles breeding in North Cyprus found that the turtles are trying to offset the effects of rising incubation temperatures by arriving at their nesting spots – the same ones they hatched from – earlier each year.

The researchers observed this pattern because of a database of information collected over the past 30 years by two teams of researchers, which contains information on the date, location, and hatching success of over 1,300 individual female turtle nests.

By placing temperature loggers into nests while turtles are laying their eggs and retrieving them once they hatch, the study showed that, since 1992, green turtles have been nesting 0.61 days earlier, while loggerhead turtles have been doing so 0.78 days earlier.

Individual females will nest 6.47 days earlier for every degree Celsius increase in ocean temperatures.

With temperatures rising at current rates, turtles need to stay on the new nesting schedule to maintain current male-to-female ratios and hatching success, which means that, for now, they are successfully offsetting climate change effects.

“The turtles are doing their bit,” the researchers said. “Now, it is up to us to ensure the continued conservation and long-term monitoring of this charismatic ocean ambassador to give them the best chance of survival in our changing world.”