The boiling frog tale is too good an allegory for our modern times to ignore. It goes like this: frogs will obliviously stay in water as it gradually warms until they eventually boil to death, blissfully unaware that their environment has become incrementally deadly. It is easy to see why this story gets wheeled out by climate change activists or democracy campaigners, along with the full spectrum of self-help peddlers who give advice on everything from bad relationships to poor diet to toxic workplaces.
As a metaphor, it is almost as frequently cited as a parable for our times as it is decried as a ridiculous myth. As a journalist who has spent decades writing about the natural world, I鈥檇 always heard that it wasn鈥檛 true. Or is it?
I am here to break some news 鈥� I have personal, first hand, long-term evidence that frogs will indeed stay in water as it slowly heats until they die.
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Let me just say from the outset that I love frogs. Ever since I was old enough to poke my hand into a puddle or a creek, I have been catching tadpoles and frogs. But I understand that not everybody is as comfortable around the amphibians as I am.
One of my very earliest frog memories was grabbing one from under a brick during a summer holiday at my grandparent鈥檚 shack on the coast of New South Wales, Australia and running over to the adults sitting around a barbecue fire drinking beer. Prone on a banana lounge was one gout-stricken adult who I鈥檇 never liked, but I was still keen to show him my frog. As I opened my hand, it hurtled free and in a huge parabolic arc flew straight into Uncle Gout鈥檚 lap, who leapt to his feet screaming in equal parts terror and agony.
Fast-forward decades later and 30 kilometres north to my own property where I have installed an outdoor timber hot tub surrounded by hundreds of acres of wild forest. It鈥檚 a new-fangled hot tub and instead of chlorine, the water is kept clean and chemical-free using ozone and a UV lamp. As far as wildlife are concerned, it is hundreds of litres of pure rainwater, a place to sneak inside cracks and hide from my resident red-bellied black snake (Pseudechis porphyriacus).
I heat the water using a wood fire and it is an extremely slow process. If I have been away for a while in winter, it can take an entire day to warm the water from less than 15藲C (59藲F) to around 38藲C (100藲F).
Ever since I installed the tub, I have had to share it with my local frog species, Peron鈥檚 tree frogs (Litoria peronii). Sure, I initially worried about what would happen to these interlopers in my hot tub, but I believed that the boiling frog syndrome was unscientific.
I also know that some species are attracted to higher ambient temperatures as a way to ward off fungal infections. So, I decided to soak away my concerns. Afterall, what kind of creature, with ready avenues of escape and a decent-ish brain, would let themselves slowly cook to death?
But at the end of those early days when my family and I would first clamber into the tub, I would find dead frogs floating, splayed out with rigor mortis and ghostly white in the hot water.
So now each day, before I light the fire, I catch every one of the hot tub squatters, moving them to a perfectly delightful, actual frog pond nearby 鈥� along with the occasional giant millipede (of whom I am scared) and spiders (for whom I feel healthy respect). And then, at frequent intervals during the heating process, I lift the lid and make sure there are no slow-cooking stragglers.
It is a pretty funny ritual, as it must be the same half-dozen individuals who make the short journey each evening from the pond back to the hot tub, only to be caught and moved each morning. It happens pretty rarely now because of my diligence, but occasionally a frog does still avoid detection, and I find it dead at the end of the day 鈥� a victim of its sacrifice to the self-fulfilling boiling frog fable.
So, what is going on?
A quick search reveals that the science on which the boiling frog story is based is thin on the pond, mostly down to a series of bizarre 19th-century experiments, including one where lobotomised frogs were compared to those with their brains intact as the water around them was heated. These early experiments showed that, for the most part, frogs will indeed leave dangerously warm water unless the heating is very slow.
In 1875, a scientist called Carl Fratscher showed that frogs stayed put when the water they were in was warmed from 20藲C to 38藲C over 2 hours and 15 minutes. But when a large flame was used to raise the temperature from 26藲C to just 29藲C in a mere 5 minutes, they tried to escape.聽
This doesn鈥檛 seem to have been rigorously tested since, and it is easy to see why such an experiment wouldn鈥檛 be conducted today. One researcher commented, when approached for this story, that they 鈥渉ope no one has knowledge of this, as it鈥檚 not the sort of experiment you鈥檇 easily get past an ethics committee鈥�.
Despite Fratscher鈥檚 upsetting experiments and my hot tub observations, at the Australian Museum in Sydney, says the frog-boiling myth is just that. 鈥淚t鈥檚 a well-quoted saying, but in most situations, frogs would perceive the increase in temperature, become more active and likely jump out of the water,鈥� says Rowley. 鈥淚n fact, frogs are highly sensitive to even small, gradual changes in temperature in both the lab and the field, and are some of the first animals to respond to climate change.鈥�
at Northwestern University in Illinois, , studied fruit flies to see what .
鈥淥ur work shows that the fly brain has circuits that are especially tuned to respond to rapid, but not slow, temperature change and that alert them to escape even before the conditions reach physically dangerous limits,鈥� says Gallio. 鈥淪o, if the rate of change is faster, they escape quicker.鈥�
He and his colleagues believe these results are generalisable to other species. But he, too, thinks that frogs will eventually escape if it becomes dangerous.
Which leaves me caught between a frog and a hot, wet place. I know what I know and, at my property, the boiling frog parable is very real. I am stuck in a Groundhog Day loop of living my 5-year-old self鈥檚 best life, catching frogs each morning to save my amphibious tub buddies from themselves.
