Climate change threatens to destabilize green turtle populations (Chelonia mydas) with the birth of a disproportionate number of females. However, a study shows how the mating habits of this species could protect it against the new danger.
The work has been published in the magazineProceedings of the Royal Society B and analyzes the structure of a green turtle population that nests in northern Cyprus. Since the incubation temperature of the eggs determines the sex of the young, warmer waters lead to the birth of more females. In the study population, in fact, 95 percent of the offspring that are born are female, which worries scientists since, since there are few males, an inbreeding situation can occur that leads to health problems in the animals.
The researchers predicted that a few males would have mated with all the females in the population. However, when performing the paternity tests on the turtle hatchlings, they observed that the proportion of fathers was much higher than expected: specifically, 28 males had mated with 20 females. That is, the offspring of each female came from one or more parents, so the danger of inbreeding disappeared.
How are these results explained? Through satellite monitoring, the scientists discovered that during the breeding season male turtles travel thousands of kilometers through the ocean so that they can mate with females from different populations. For example, the males studied could have mated with tortoises from elsewhere in Turkey and even North Africa. For the researchers, this is good news as the observed mating pattern could protect the turtles from the adverse effects of warming waters.
