Everyone’s talking about . . .

TURTLES

Why are they in the news?

SCIENTISTS claim climate-change is turning them female. Researchers examining one species — the green sea turtle — north of the Great Barrier Reef in Australia found that 99.1 per cent of juveniles and 86.8 per cent of adults were female.

How’s that happened?

UNLIKE mammals, whose sex is determined by their chromosomes, for turtles it depends on the temperature during incubation. If eggs are laid in sand just a few degrees warmer than normal, it can lead to a drastically higher proportion of female hatchlings.

Why do they do that?

ONE theory is that males do better in cold temperatures and females when it’s warmer — so it makes sense for them to adopt the right sex for their surroundings.

How long has the imbalance been going on?

APPARENTLY, the north of the Great Barrier Reef has been ‘producing primarily females for more than two decades’. With climate change said to be leading to warmer temperatures, the trend for more females is only likely to continue. That can’t be good.

So, male green sea turtles aren’t long for this world?

NOT quite. Thankfully the trend for mostly female isn’t true everywhere. Sixty-five to 69 per cent of turtles further south on the reef, where waters are colder, were female — close to the natural ratio.

Is there anything we can do?

EFFORTS to tackle climate change will, if effective, help to prevent future warming. Conservationists are also trialling ‘shadecloths’ — sunshades on nesting beaches to lower the temperature of the eggs.

And then everything will be all right?

SADLY, it’ll take more than that to keep them safe. Green sea turtles are classified as endangered on the UN’s Red List of Threatened Species. Other threats include poaching; egg-theft by predators and humans, getting tangled in fishing lines; the destruction of their habitat; and death from eating plastic particles. Turtles have survived in our seas for more than 100 million years. But there’s no room for complacency.