The call of the canary in an age of extinction

‘The canary in the coalmine’ is a metaphor that has almost circled back to return to its literal meaning. From its original reference to the use of canaries to gauge the levels and leaks of toxic gases in mines, it came to refer to an indicator, an early warning, a sign. In that usage, it has become so common as to be considered a cliché, best avoided. But thinking about birds—caged birds, wild birds, birds on the brink—I cannot find a more fitting metaphor for their plight.

This week, it’s ducks. Ducks filled with lead from the continued use of lead bullets for hunting—despite these bullets having been banned in Victoria for twenty years or so. The ABC reports that, although the Environmental Protection Authority has apparently been aware of ‘elevated’ levels of lead in ducks from several Victorian wetlands since 2018, it did not make this information public because testing was ‘inconclusive’. Retesting of ducks in 2020 found the birds to contain lead levels that posed potential risks to human health. Still, testing is ‘inconclusive’. Further testing is ‘still underway’.

What is the measure of harmful, and how much harm will be inflicted—to the ducks, the food chain, the birds of prey—while this testing remains underway? CSIRO states that ‘even tiny traces’ of lead are extremely harmful to humans and animals. Harms include cardiovascular disease, lowered IQ and impaired kidney function. The World Health Organisation puts it plainly: ‘There is no level of exposure to lead that is known to be without harmful effects.’

I could go on, but I would be only recapping, retelling, regurgitating the news I read this week. Maybe you read about the King Island Brown Thornbill, the King Island Scrubtit and the Grey Range Thick-billed Grasswren—three of our ‘highly endangered birds’, with less than one hundred of each species left alive. About the significant drops (up to 80 percent over the last thirty years) in migratory shorebird populations in this country, on account of disturbed and destroyed wetlands and intertidal habitats, as well as those en route, relied upon to bridge the distances. About degraded or disappeared environments all over the Earth, leading to unprecedented species decline. Or maybe you avoided reading any of it, because to read more stories like these, without feeling you have the agency to change the course of things, sends you into an anxious swirl that soon spirals into grief or anger, or despair.

Follow the story of any bird in the current ‘climate’, and soon the same stark array of statistics and stories await you, just as if you’d stepped into the woods of one of those old European fairytales, and the forest had closed behind. For it is dark in here amongst the data, and sunlight is scant.

It was Scotsman John Scott Haldane who came up with the idea of using birds—mostly, but not always, canaries—to measure the levels of toxic gases, especially carbon monoxide, in mines. After graduating in medicine in 1884, Haldane became interested in the composition of air and its effects on human physiology. Later, he studied asphyxia in coal miners. After embarking on a series of self-experiments involving the inhalation of several toxic gases, Haldane declared carbon monoxide to be the cause of deaths in the mines. He suggested miners carry small animals, like mice or canaries, to detect dangerous levels of gas when underground, making the mine a laboratory of sorts. If the animal became sick, miners knew to get out, or reach for respirators. The practice carried on well into the twentieth century, with caged birds replaced by electronic gas detectors, as late as 1986 in Great Britain.

Canaries have also been used, since WWI, as detectors of poisonous gases in war fields. As recently as 2003, during the Iraq War, the Financial Times reported that canaries were in high demand in Baghdad, where they were considered as ‘the only chemical weapons detector available’ for the local population. According to The Times after 9/11 triggered fears amongst New Yorkers about a chemical terrorist attack, ‘canary breeders could barely keep up with demand.’

Birds are vulnerable. They are especially vulnerable to airborne poisons because they have extra air sacs, enabling them to take a double dose of air—one dose when they inhale, another when they exhale. This prevents altitude sickness. Even at rest, their oxygen consumption is higher than any other vertebrate, and then it increases many times again during flight.

Why the canary? Size, apparently, had a hand in it, as well as the bird’s call. Canaries are quite loud, meaning their silence was a sure sign that something had gone wrong. Moreover, canaries were cheap and relatively easy to come by. Many mining companies in the UK purchased birds from pet shops or directly from breeders. Some mining companies even had their own aviaries.

And the cages, they were not as you might imagine. While some resembled domestic bird enclosures, historical images show they were often cruelly miniscule, sometimes smaller than a shoe box. Originally fabricated from metal or timber, they were later made of clear acrylic sheets with ventilation holes drilled on one side. Is there any more miserable way to imagine a winged creature?

Science Museum Group. Cage for reviving canary. Y2002.19.254.1 Science Museum Group Collection Online. Accessed October 26, 2022.

While photographs are relatively easy to come by of miners proudly carrying their caged canaries, like briefcases, to the underworld of the mine, the historical record has spared us pictures of birds swaying from side to side, or fallen from their perches. Of dead birds on cage floors. While some miners apparently carried small vials of oxygen to revive the birds if necessary, it was Haldane again who later invented resuscitation devices. The resuscitators resembled small cages, with oxygen cylinders on top, allowing the fallen bird to be brought back to life. Rather than this invention saying something about a concern for the wellbeing of the birds, more likely it was a cost-saving device. Many birds were taken down into the darkness of the pit repeatedly, after each revival.

Not everyone condoned the practice. As early as 1925, in a small article in Scottish newspaper, the Dundee Courier, Dugald Macintyre argued that, as useful as they had been in saving lives, ‘it seems a queer thing that in this age of science a proper hand instrument cannot be invented to take the place of the harmless and useful birds in testing mines for gas.’ Still, the practice would continue for another sixty years.


This year marks sixty years since the publication of Rachel Carson’s seminal work on the environmental impact of blanket-spraying synthetic pesticides. Silent Spring begins with ‘A Fable for Tomorrow’, written like a folk tale, in which mysterious maladies afflict animals and humans, and birds that could not fly. Carson describes a ‘strange stillness’ that has befallen the countryside, an absence of birds and birdsong. With the ‘new kinds of sicknesses appearing’ and ‘vegetation as though swept by fire,’ to read her words now is to be chilled by the collision of the predicted and the present. Surely, we are living the tomorrow Carson could foresee.

But Carson was no Nostradamus. She was a marine biologist, a conservationist, a writer, who drew on real events that were happening in her time. She wrote into a world of vanishing birds and other species on account of the widespread use of insecticides, such as Dichloro-Diphenyl-Trichloroethane (DDT). Initially introduced in the 1940s to fight malaria, typhus, and other insect-borne human diseases, DDT was later used for insect control in crop and livestock production, as well as homes and gardens.

At the time of Carson’s writing, the Peregrine Falcon was one species in a state of drastic decline across the northern hemisphere, on account of the build-up of DDT and dieldrin in their bodies, from consuming contaminated prey. The impact on these magnificent raptors was to alter their calcium metabolism, leading to eggshell thinning so extreme that shells were unable to hold developing chicks. Birds would crush their eggs with their own weight during incubation. By 1970 in the United States, and eight years later in Canada, the Peregrine Falcon was listed as ‘endangered’. Since the ban on DDT that followed, populations have famously recovered. Yet still, regulations regarding the use of pesticides are not consistent across the globe. According to Pesticide Action UK, Australia still authorises the use of 144 ‘highly hazardous’ pesticides, almost double the amount permitted for use in the UK. (As if birds respected borders, anyway.)

To tell her tale, Carson drew upon actual events which had happened ‘somewhere’, though not all in the same place. Her embedding them in the one story, the one location, is what makes this first section of Silent Spring fable-like. It’s just too much. Just like for our generation the climate stories have been ‘too much’. The statistics are overwhelming, the daily litanies of species loss and other environmental catastrophes relentlessly bleak. When it comes to nature, there is trouble everywhere, a combination of direct and indirect human intervention and impact. And all of it being painfully recorded by scientists and writers alike, as they try to mitigate, measure, or at least bear witness to the diabolical story of species loss unfolding in our times.

It is as if all living species have become sentinel species—monitors and measurers of the experiment of modernity. The more sensitive the creature, the more susceptible to environmental hazard. Take the honeybee: exploited by humans for both honey and beeswax, honeybees feel the impact of air pollution more acutely than humans. A recent study in India found that even mildly dirty air could kill 80 per cent of giant Asian honeybees, a key pollinator in South Asia. The three-year study found that bees collected at more polluted sites were far more likely to be flecked with particles of toxic heavy metals, such as arsenic and lead, had irregular heartbeats (a sign of poor cardiac health) and lower levels of blood cells (signifying a compromised immune system). Which is not only bad for the bees, but bad for crops relying upon pollination.

Take the honeybee, take the birds, take the beasts. Take any of those vanishing insects, lesser known. Even with the mass deaths and declines we have seen in the past decades—with categorisations such as ‘vulnerable’, ‘endangered’, ‘critically endangered’ and ‘extinct’ becoming so familiar as to be almost benign—still the waterways and airways are not being cared for with a determination that befits the size, scale and urgency of the problems.

Or take the Powerful Owl, our largest species of owl. With their forest habitat in south-eastern Australia so badly degraded from felling, these owls have fled to the cities. But trees can take 150 to 500 years to develop hollows that can adequately house a pair and their owlets. Owls need old trees to breed. To endure. The situation is so dire for these birds that a team at Melbourne School of Design is trialling the use of 3D technology to build artificial hollows with wooden blocks, fabricated to fit snugly in Sydney blue gums. It’s clever technology, undeniably, and it is a good news story for the owls. Yet at the same time, it seems such a strange indictment of the state of things. Hadn’t nature mastered the design already? If we have the technology to replicate nature, will it matter less that we continue to destroy it? Why not simply save the trees?


The canary in the coalmine was caged. The cage, and the forced endurance of an endless night, were its main forms of oppression, even before the possibility of breathing in lethal gases. But still, these cruelties are easier to measure than the ways in which uncaged birds are suffering on account of habitat destruction, pollution, extreme weather events, chemical poisons, and climate change.

Almost half of existing bird species worldwide are known or suspected to be in decline. If birds were only barometers of the biosphere, is this not indication enough that our habitat, our home, is in terrible trouble? And yet things go on, as if nature can be revived, over and over, ad infinitum. Like the resuscitated canaries. As if life on Earth was cheap.

There is something profoundly absurd about all of this. Being asked to wait for further signs, further testing, further evidence, when everything is before us, in plain sight. Building nest boxes to save the birds, while land clearing continues. Banning pesticides in one country, while their usage continues in another. Erecting signs on beaches that warn of nesting sites, while ushering cars along the sand. It might be the disparity, more than anything, between what we know, and the lack of an adequate response, from governments and corporations especially, that is the greatest cause of anxiety and anger and grief. For it requires us to suspend our instincts as well as our intelligence. It requires us to remain living in a fantasy.

The stories filter in singularly, as if each is happening in an isolated place and time, unconnected. If only we could see everything at once, as in Carson’s fable, and then the often-invisible web that connects everything, including us, to everything else. How we are all embedded in the same biosphere, breathing the same oxygen, drinking the same water, ingesting the same foods, from the same soils. How all species are interdependent.

‘The canary in the coalmine’ is an overworked phrase, but has its used-by date really expired? The literal and figurative, it would seem, have dissolved. One might insist, its time is now. But not as a means to keep noting the impact, measuring the fallout, counting the losses. But as a call to action, as plaintive as the cry of the bush stone-curlew, as commanding as the call of the crow.

Image by Kaikara Dharma

Dani Powell

Dani Powell grew up in Meanjin/Brisbane, and has lived in Mparntwe/Alice Springs for over twenty years. She is both writer and performance-maker, and her debut novel Return to Dust was published in 2020 by UWA Publishing.

Overland is a not-for-profit magazine with a proud history of supporting writers, and publishing ideas and voices often excluded from other places.

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