The wild painted turtles I enjoyed watching as a child will be gone.
Males don't stand a chance in a warmer world, if they happen to be painted turtles. A temperature rise of around 1 °C is all it would take for the species to become 100 per cent female and earmarked for extinction.
Painted turtles (Chrysemys picta), found in lakes and streams across North America, are one of many reptile species whose sex is determined by temperature. Eggs in warm nests are likely to hatch as females, while males hatch in cooler nests, although no one is sure why.
In recent years, many researchers have raised concerns that global warming could skew the sex ratios of these reptiles. Rory Telemeco and his colleagues at Iowa State University developed a mathematical model to predict whether the painted turtles might be affected.
In a preliminary test of the model, the group correctly predicted the sexes of 40 out of 46 hatchlings born in the wild.
Telemeco's team then used the same model to predict what might happen to the sex ratio of future hatchlings. Conservative climate models predict that average temperatures in the US Midwest will rise by 4 °C over the next century. The group's model suggests that this temperature hike would result in nests of all-female hatchlings, even if the turtles nest earlier, when temperatures are cooler. In fact, average temperatures only need to rise by 1.1 °C to have this effect, the team found. "It's ultimately extinction," says Telemeco. [emphasis mine]
Climate change will wipe out many species - this is one of them.
Thank you Ruth!