99%+ Of Green Sea Turtles Born In Key Breeding Area Female Thanks To Rising Temperatures
Warming temperatures are having a profound and potentially devastating impact on one of the most important green sea turtle populations in the world. Scientists were surprised to find that "virtually no male turtles" are being hatched in a key breeding ground in the northern Great Barrier Reef.
Like many reptiles, the sex of a turtle is determined by how warm the egg is as it's being incubated. And small temperature differences can cause dramatic changes in the male-to-female ratio. "Within a few degrees Celsius you go from 100 percent males to 100 percent females," says marine biologist Michael Jensen. "A really narrow range, that transition." The team's research was published this week in Current Biology.
The scientists studied turtles from two distinct breeding grounds – a larger population from the warmer northern Great Barrier Reef, and a smaller population from a cooler area about 1,200 miles to the south.
What they found was dramatic: the population that hatched in cooler areas is about 69 percent female. But in the group from the warmer north, scientists found more than 99 percent of juvenile and young adult turtles are female.
EDIT
https://www.npr.org/sections/thetwo-way/2018/01/10/576807635/climate-change-means-virtually-no-male-turtles-born-in-a-key-nesting-ground
