A five year study of hatchling loggerhead turtles in Florida shows that temperature increases skew populations towards females, which ranged in different sites and years from 87 to 99.9 percent of the population. This, according to the Canadian researchers, "may complicate conservation efforts, since global warming might be expected to skew the ration still further towards females." They conclude that "in Suriname, even a 2ƒC warming of the sand would put temperatures in the female- producing range for the entire present nesting season of green and leatherback turtles. Perhaps extinction would follow." (N. Mrosvovsky and J. Provancha, "Sex ration of hatchling loggerhead sea turtles: data and estimates from a 5-year study," Canadian Journal of Zoology, v. 70, p. 530 - 538, 1992).
"Demonstrations of sex-ration evolution in faster maturing species do not make it safe to assume that turtles will survive rapid global warming. Indeed one conceivable explanation of the skewed sex ratios in our study is that the climate at Cape Canaveral has already started to change, and that the sand temperatures for 1986 - 1990 were above the average for the last few hundred years." N. Mrosvovsky and J. Provancha
GREENPEACE Climate Impacts Database