Long, long ago, in an earlier pre-digital epoch, many of my childhood evenings were spent in front of my parents’ old radiogram. As darkness closed in outside, the illuminated dial on the face of the unit glowed all the more brightly; emblazoned with names that now stand out equally sharply in my memory. Hilversum, Kalundborg, Luxembourg, Lahti: faraway places where radio masts sent their invisible signals through the damp night air, and whose regular, identifiable presence in the otherwise unstable space of the airwaves provided a semblance of order and a source of familiarity.

As I recall it, the radio had three bands: short wave, medium wave and long wave. Much of what I could pick up on short wave (minicab or police car messages, amateur radio ham chatter) seemed to come from only a short distance away, but was often disarmingly short-lived; suddenly surfacing, then quickly disappearing, like breakers on a shore. By comparison, the stations I tuned in to on medium wave or long wave were rock solid – islands in a sea of white noise. Even then, though, attention would oscillate, from background to foreground and back again, as time slipped by. As the hour grew late, different sounds would start to circulate: some instantly recognisable, others unusual and strange. If you kept your ears peeled, there would often be things you hadn’t heard before. 

In Maeve Brennan’s video Listening in the Dark (2018), the dulcet, radio-friendly voice of naturalist David Pye (his name a reminder of a long-lost British electronics manufacturer and a homonym for the magic number that is a key to the universe) describes his nocturnal forays with a ‘bat detector’, a piece of home-made electronic apparatus that translates the high-pitched noises of bats into something audible to the human ear. Many of the sounds bats make in flight are at a frequency outside of the range of human hearing, just as the purpose of these sounds was, for a long time, outside the grasp of human understanding, until the pioneering scientist Donald Griffin demonstrated their significance in the hitherto unexplored phenomenon of echolocation. Brennan circles back, time and again, to the figure of Griffin in her film, which also orbits around questions of otherness and consciousness trailed in Thomas Nagel’s seminal essay ‘What is it Like to Be a Bat?’: a precursor of a new vogue of interest in animal sentience and intelligence, and a touchstone for a recent school of radical eco-philosophy which highlights the intricate, intimate entanglement between the human species and the other life forms with whom we share the world. 

It is human actions, more often than not, that upset that delicate balance – so much so that it is now commonly accepted that Planet Earth is in the throes of a new phase in its long and multi-layered history: the Anthropocene. While there is a growing consensus that a line has been crossed and a tipping point has been reached, we are still in the dark about the full extent of the likely repercussions. One example of humans’ direct impact on bats is all too tangible, however – namely the disconcerting litter of bat corpses that has increasingly been found in the proximity of wind turbines, their skin unscathed by rotor blades but their lungs exploded by dramatic changes in air pressure. These incidents are doubly tragic: not only do they suck the breath from the body of a blameless fellow creature, but they also take some of the wind out of the sails of the otherwise compelling ecological argument to move towards alternative energy sources and away from an extractive carbon economy. It is the worst kind of knockback: even when we humans do the right thing and try to remedy the environmental damage we are causing, we open up a Pandora’s box of unintended consequences. If the canary in the coal mine acted as the alarm call for the age of fossil fuel, the image of the battered bat may go down as a sad case of friendly fire in the wider campaign for a better, kinder, greener future.

Green energy companies and bat conservation groups have made significant efforts in mitigation, exploring alternatives for turbine placement or making subtle tweaks in turbine design. And, as time goes on, bats, too, may learn new strategems of avoidance, tuning in to when turbines are active, and when they go quiet. Brennan finds some solace, at least, in the lessons of evolutionary history. While we learn, from the fossil record, that bats seem uncannily unchanged from their arrival on the scene more than 50 million years ago, the scientists she interviews remind us that this pristine, primordial appearance is deceptive. Patterns of behaviour are always evolving. And no more clearly than in the ongoing interactions between bats and their insect prey. In a military metaphor that continues a subtext that runs throughout the film, this constant struggle to maintain a competitive advantage is portrayed as a kind of ‘arms race’, in which the disorientating feints and manoeuvres of moths to alter the speed or trajectory of their flight (and thereby mess with its wavelength) enjoin the bat to ever more fine-tuned feats of listening and hearing. These mid-air gambits have been going on for millions of years: needless to say, outside the reach and the wherewithal of humans. 

A recurring feature of Brennan’s practice as a whole is its penchant for (re)forging connections across historical eras. In works like The Drift (2017) or An Excavation (2022) the impulse is archaeological or museological, piecing together fragments of lost objects or restoring the provenance of purloined artefacts. Part field study, part research enquiry, Listening in the Dark plots a similar arc: reaching back through the recesses of time; sounding, probing, following echoes wherever they lead. Grainy black-and-white footage of Donald Griffin’s echolocation experiments from the 1940s segues into a discussion of their significance in the wartime development of radar, whose combing of the ether, in turn, suggests an imaginative lens or metaphorical portal through which to peer into the deep and distant past.

It’s not too much of a stretch to describe Listening in the Dark as operating across three parallel time-bands: short, medium, and long. If the majority of the action in the present moment revolves around the lives (and deaths) of bats, its wider backstory extends to the beginnings of life on earth, and even further beyond. The film’s soundscape, too, is a resonant study in parallel wavelengths. Although it is the high-frequency squeals of bats that first garner our attention, Brennan’s atmospheric soundtrack carries a deeper subliminal undertone – redolent, perhaps, of the slow and barely discernible rumble of rocks groaning and tensing over huge expanses of time. Before the film’s opening credits have rolled, Brennan pastes up an emblematic quote from the eighteenth-century geologist James Hutton, which hints at the earth’s extraordinary capacity for renewal and repair. Hutton’s words appear over images of waves rolling in at Siccar Point on the Scottish coast near Edinburgh, a prominent example of what Hutton terms an ‘unconformity’ – a geological phenomenon where rock formations created by different processes and in different eras abut. In Hutton’s view, this unforeseen conjunction was proof that geological forces are dynamic, disruptive, ever evolving. It was, in the full meaning of the phrase, a mould-breaking insight: one that threw previous conceptions of the age and origin of the planet into question in many different ways.

Brennan bookends her film with another uplifting, surprising image – an anecdote about the discovery of coral reefs that are forming around the bases of offshore wind farms. A hopeful rejoinder to the earlier doleful litany of bat deaths, this deus ex machina is a further beguiling reminder that life does not always conform to expectations. Nothing is decided, one way or the other – change is life and life is change. We should know this, too, from the changing, contrasting meanings we bestow on the figure of bats. Harbingers of ill omen to some, they are symbols of rebirth to others. And while they may have shaken off some of their storybook associations as supernatural demons from the underworld, bats are still, by and large, denizens of the unknown. Crossing a border into unknown territory, which is many people’s experience of the climate emergency, can prompt feelings of foreboding, even fear, but there are always, if we venture to look around us, signs of possibility and hope. As Listening in the Dark attests, we just need to keep our eyes and ears open. At what feels like an increasingly nervous moment of impending crisis, Brennan transmits her reverberant bat signal through the gathering gloom. Best not expect a superhero to respond. Human beings are going to have to figure this one out for themselves.