In the hypothetical case that the population of an animal species began to become the same sex, that species would be seriously threatened. This is what is happening precisely with the green sea turtles. The high temperatures seem to be turning 99% into females.
It so happens that these turtles do not become males or females due to sex chromosomes, like humans and most other mammals, however, the temperature outside of a turtle egg influences the sex of the embryo in the increase. And this strange biological peculiarity endangers their future in a warmer world, according to the researchers.
In fact, some populations of sea turtles are already so skewed by the heat that young reptiles are almost exclusively females, according to a new report in the journal Current Biology. As the biologist David Owens explains:
This is one of the most important conservation documents of the decade. It will not be long, perhaps over the course of a century, until there are not enough males in sea turtle populations.
In the presented study, two genetically distinct populations of Great Barrier Reef turtles were examined. The results showed a moderate female sex bias (65%–69% female) in turtles originating from the cooler southern GBR nesting beaches, while turtles originating from warmer northern GBR nesting beaches were extremely female-biased (99.1% of juvenile, 99.8% of subadult, and 86.8% of adult-sized turtles).
Combining our results with temperature data show that the northern GBR green turtle rookeries have been producing primarily females for more than two decades and that the complete feminization of this population is possible in the near future.
As they explain in the work, “it is clear that climate change represents a serious threat to the persistence of these populations.” For Dermot O’Gorman, director of World Wildlife Fund Australia, the results are ” a clear signal of the impact of climate change that needs urgent action “.
In the case of turtles, the short-term solutions are really unusual. Scientists believe that building a kind of giant umbrella, an awning on most known nesting beaches, could reduce the temperature of the sand. A fight against the clock to save a species that does not produce enough males because of the high temperatures. [ Current Biology via The Washington Post ]