Fun Fact: Sea Turtle Gender is Climate Dependent.
Bad News: it’s Heating up.
Sea turtles come in droves to same beaches year after year. The turtles crawl up shore onto the sandy beach and start to dig. They dig and dig with their flippers, some for more than 40 minutes until they create a hole deep enough to protect their precious eggs. You can see the females heave with exhaustion during the grueling process. Once it’s over they’re so tired, getting back to the water is slow and rest-filled.
For decades these turtles have been coming back to the same beach so that they may complete the circle of life that keeps their species going. Recently, however, scientists have found a concerning chink in the chain.
You see, according to the study published in Current Biology, “in all species of sea turtles, sex is determined by incubation temperature during embryonic development. In sea turtles, cooler temperatures produce more male hatchlings while warmer temperatures produce more females.”
These scientists studied Green turtles off the coast of Queensland Australia. In the North Great Barrier Reef, of the turtles surveyed they found “extremely female-based sex ratios.”
99.1% of juveniles turtles being female
99.8% of subadults turtles being female
86.8% of adult-sized turtles being female
The study says, “increased sand temperatures affect the sex ratios of the [North Great Barrier Reef] population such that virtually no male turtles are now being produced from these nesting beaches.”
Sea turtles take years to mature and are naturally drawn to the beach they hatched on. Because of that, the study says, these turtles may not change their mating patterns as quickly as climate changes.
“Our study highlights the need for immediate management strategies aimed at lowering incubation temperatures at key rookeries to boost the ability of local turtle populations to adapt to the changing environment and avoid a population collapse—or even extinction”
Other climate gender-dependent species include the monarch butterfly, the crocodile and many other reptiles.