Guest essay by Eric Worrall
Apparently we now need to shut down industrial civilisation to prevent “local extinction” events, scary short distance migrations to more favourable territory.
Climate change could make flatback turtle population be born all female or die out, scientist warns
By Jane Bardon
The members of one of the Northern Territory’s largest flatback turtle populations could all be born female in less than 15 years if rising temperatures continue unabated, a leading Australian turtle scientist says.
The Honorary Fellow of Charles Darwin University and head of AusTurtle has used sand probes to monitor the rise in nest sand temperatures over the decades on the island and at other sites, including Ashmore Reef.
The sex of hatchlings is determined by the sand temperature of their nests, and in 2016 all the Bare Sand Island nests were too hot to produce any males.
“If the temperatures are below about 29.5 degrees [Celsius] we have a male turtle, if it’s above 29.5C you’re going to have a female turtle,” Dr Guinea said.
“And if you have a rise above about 33C to 34C, you start getting into lethal temperatures.”
Dr Guinea said by 2030, all of Bare Sand Island’s flatback hatchlings could be born female.
But he still hoped some nesters would seek out cooler beaches.
“We might find that further south, the turtles are actually having better success there, they could be the saviours for the population,” he said.
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I live near a flatback turtle nesting site, at the right time of year the beaches are thick with hatchlings – around 1,500 miles south of the “endangered” colony. Somehow I suspect the strategy of moving south a little in response to global warming is working out.
Update (EW): Deleted a redundant sentence in the last paragraph
I suffered local extinction in Palo Alto when I moved to WA.
Yes, I want this applied to HUMAN populations, too. If people move, it has to be due to climate change. Can’t be due to local jobs, better opportunities elsewhere, moving closer to family, etc. It must be climate change and until we get humans NOT to move away from where they are, we must work day and night to save the local populations.
/s if I need one.
I doubt that every female member of the species lays eggs that have the exact same temperature response. Some will have males at higher temperatures than claimed while others will have the divide be at lower temps. If temps continue to rise the eggs with the male/female divide at a higher temp will make up a disproportionate amount of the males, causing the male/female divide temp to rise throughout the species.
This is basic evolutionary theory. I would have thought scientists (especially biologists) would know this.