Australian researchers say global warming is forcing endangered turtles to abandon traditional breeding sites and head south, in search of cooler conditions. They believe that hotter temperatures in the tropics have made the sand too warm for eggs to incubate, forcing rare loggerhead turtles to seek sanctuary on North Stradbroke Island, off Brisbane. There are concerns that baby turtles are at risk from foxes, pleasure crafts and four-wheel drive vehicles.
Loggerhead turtles in Australia nest on open beaches where the temperature of the sand must be between 25 and 33 degrees for their embryos to develop successfully.
Some of these carnivorous reptiles have traveled down the Queensland coast to North Stradbroke Island, looking for more benign surroundings to lay their eggs.
But researcher Jennie Truman believes that, after escaping hotter weather further north, the turtles are at risk from tourists driving their cars on one of the island's most popular beaches. "The sand temperature has started rising up there which is cooking the eggs, basically, and they are not incubating. Flinders beach, at the moment, where we have two nests, is basically a highway in the summertime not a beach," said Truman.
Loggerhead turtles are also at risk from foxes, which dig up the eggs, and have also been struck by boats and jet skis.
Researchers are also worried that climate change could further destabilize the population of the endangered species because the sex of hatchlings is determined by the incubation temperature of the eggs.
In warmer sand, it is likely that females will be hatched, while cooler conditions result in more males being born. The concern is that as temperatures heat up, the ratio between males and females will be distorted, which potentially could affect breeding patterns, in the future.
Rising sea levels and an increasing number of cyclones could also lead to the erosion of nesting beaches or wash away nests.
Loggerhead turtles, named after their large head and powerful jaws, are also found in the Indian Ocean, the Gulf of Mexico and along the southeastern coast of North America and the Mediterranean Sea.
They were once widely hunted for the eggs and meat but now have international protection.