Olgui/ecology

Male turtles can't stand the heat
temperature-dependent sex differentiation
From the page: 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.

As global temperatures rise, male turtles may start to lose their cool. 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. Climate change compounds the threat of localized habitat destruction for these sensitive reptiles. Global warming predictions range from a 1� to 6� Celsius mean temperature increase over the next century, and studies have shown that as little as a 1� increase in mean incubation temperature can dramatically reduce the ratio of male turtle hatchlings to female. A 4� increase effectively eliminates male turtles from a clutch.

photo: male box turtle. Credit: Constance McGuire
thanks Nutmeg


see also Decline in turtle nests Study