Shells and Feathers: Climate Change Affects All

If you've ever had difficulty finding a date, consider the plight of the loggerhead turtle. Although this species has been around for more than 60 million years, climate change is threatening their future reproduction. Researchers from Florida Atlantic University have just published the results of a four-year study in the journal Endangered Species Research.

The sex of sea turtles is defined when they're still in their eggs, which develop in underground nests. Warmer conditions produce females and cooler conditions produce males. The research team documented rainfall, nest temperatures, and other measurements at a loggerhead turtle nesting beach in Boca Raton over the course of four years. The majority of the loggerhead hatchlings entering the northwestern Atlantic come from this area. Most of the hatchlings in the sampling were female, suggesting that nest temperatures were not sufficiently cool year-round to produce males.

"If climatic changes continue to force the sex ratio bias of loggerheads to even greater extremes, we are going to lose the diversity of sea turtles as well as their overall ability to reproduce effectively," says Jeanette Wyneken, Ph.D., professor of biological sciences in FAU's Charles E. Schmidt College of Science.

A mama loggerhead lays roughly 105 eggs per nesting season, which spans April to October. Only one in 2,500 to 7,000 sea turtles makes it to adulthood. A female would have to nest for more than 10 nesting seasons (over the span of 20 to 30 years) just to replace herself and possibly one mate.