Male Turtles Can't Stand the Heat

As global temperatures rise, male turtles may start to lose their cool.

Many reptiles, including most turtles, display temperature-dependent sex differentiation. In other words, the temperature that an egg incubates at determines the sex of hatchlings. In the case of turtles, warmer temperatures yield more female offspring, and cooler temperatures yield more males.

A new study by Stephanie Kamel and Nicholas Mrosovsky of the University of Toronto documents the peril of Caribbean hawksbill sea turtles as coastal forests disappear—and with them, cool, male-producing nesting sites.

Long-term sex-ratio bias is a real concern for sea turtles, Kamel said.

Worldwide, a population bias already exists against male sea turtles. Largely female sea turtle populations are common, whereas male-skewed populations are almost unknown.