The turtle wranglers landed on Ingram Island thinking about sex and heat.
Pacific green sea turtles spend years cruising this northern Australia feeding ground, fattening up on sea grasses before heading to nesting areas to mate and lay eggs. The scientists simply wanted to know: which of these reptiles were male and which were female?
You can’t always tell a sea turtle’s sex by looking, so researchers kicked off a “turtle rodeo.” They stood atop skiffs and raced toward swimming turtles and launched themselves like bull wrestlers onto the animals’ carapaces. After gently steering each turtle to shore, they took DNA and blood samples, and made tiny incisions to inspect turtle gonads.
Since the sex of a sea turtle is determined by the heat of sand incubating their eggs, scientists had suspected they might see slightly more females. Climate change, after all, has driven air and sea temperatures higher, which, in these creatures, favors female offspring. But instead, they found female sea turtles from the Pacific Ocean’s largest and most important green sea turtle rookery now outnumber males by at least 116 to 1.
Photo: Dustin Haney/Unsplash