20 years ago, when I could still hear well enough that going to the movies was a pleasure, I saw Jeremy Podeswa's melancholy film, The Five Senses. Among its interwoven narratives is the story of a man who, aware he's losing his hearing, goes about collecting sounds: a recorded aria, the patter of rain, a lover's heartbeat, his daughter's laughter. Birdsong, I wanted to say to him. Don't forget birdsong.

Sound memory. When I hear the song of a western meadowlark — a quick string of notes bright as beads — I am for a moment a girl standing in a back yard at the edge of a small prairie town. A bounded circle of child-world. Hoppers in the quack grass click and whirr. The sun shines on the split-log siding of the house, and when I put a palm to it I feel the warmth. Over by the alley, where the honey wagon stops twice a week to collect the bathroom pail my dad carries out, stands a well-nourished chokecherry tree. Closer to the house, a scraggly Saskatoon bush might yield a berry or two the birds have left behind, wild and sweet and seedy.

What I've just described is only a memory of a memory by now, unsound, but still it's where those few flung notes will land me for as long as I can hear them.

Over the past half-century, North America has lost almost 3 billion birds, a slide in the breeding population of 29 per cent. The disappearing birds include species we think of as widespread, common as weeds: sparrows, warblers, swallows. Grassland birds, the meadowlark among them, have shown the greatest loss: 53 per cent.* The fabric of the plains is wearing thin.

The female meadowlark is a weaver. Often her nest will begin with a small depression in a hayfield, a pasture or a ditch where wild oats bend in the wind. The hoof-print of a cow will do. She'll shape the hollow with her bill and line it to make a soft bowl, then interweave grasses with surrounding growth and pliant twigs to form a domed roof that will shed rain and, with any luck, hide her eggs from predators. On her travels out and back, she'll wear in runways that lead to the entrance on one side.

Another rounding: deep in the human inner ear sits the cochlea, a fluid-filled structure that coils inward like a snail shell. Inside this tiny chamber are thousands of cilia, submicroscopic hairs, attached to nerve cells. When sound waves enter through an opening called the oval window, the cilia bend back and forth, translating vibrations into signals that course along the auditory nerve to the brain. Or that's how hearing ought to work. Cilia will wear down over time. Loud sounds can hit them hard enough to bend or break them, even shear them off.

It might have been the April Wine concert at the high school gym where I danced with such abandon I lost my specs or the night Chicago played the Coliseum or any number of basement parties with sound systems cranked to 11. Maybe it was the job in the roaring bar where the university football team took up all five tables along the east wall; or the racket in the garment factory before the days of mandatory ear protection; or simply a marriage of bad-luck genes. Until I was in my early 40s, I could almost pretend it wasn't happening.

An audiologist leads me into a closet-like white room and snugs a metal band around the back of my head. I feel a pressure point behind each ear. "Tap this button when you hear the beep." I've worn hearing aids for almost 20 years. Recalibrate, reprogram, find a more sophisticated model, try again. I've reached the practical limits of my latest pair. The audiologist charts the results of my tense 20 minutes of listening and confirms my hearing loss has slid from moderate to moderately severe. She offers that with cadillac technology and expert tuning we might engineer small improvements —for now. For the future, she offers a sigh.

She fits me with new hearing aids, and so begins a months-long struggle with unbearable background noise and failing conversations. I'm told I talk too loud. Of course I talk too loud. Would everyone speak up, please? I return those hearing aids and resort to a branded clinic. The price triples. The devices are high-end and the person who fine-tunes them is a pro. Still, dining halls are painful. Conversation with soft-spoken people is impossible. Groups of more than half a dozen exhaust me. I begin a notebook of my sideways conversations.

My husband returns from his errands one Saturday and tells me, "I couldn't find any reason for you."

"Any reason for me?"

"Riesling. I couldn't find any Riesling."

Spring, and the colours of the male meadowlark are at their most intense — a sunny yellow throat and belly, a dramatic wedge of black across his chest. For several hours a day he perches on post or wire singing out his claim to six or seven acres. A month might pass before possible mates arrive and courtship can begin. At my desk inside a plain white cube of a room I listen online to recordings of his song and its dozen variations, fluting, sunlit, short. I scroll through images of oven-like nests, spotted white eggs, and gaping beaks of the young, their open throats pink and urgent. The smells of spring on the grasslands rise around me: soil still moist, a low-spreading wild rose, a whiff of rain on the breeze. Textures tease my fingertips: the tiny hairs on a head of blue grama grass, a keen-edged spear of wild oat leaf I can make a whistle of. A morning immersed in this show of light and sound, touch and scent, stirs a whirl of ache, one part delight, one part nostalgia, one part mourning.

By a meadowlark's reckoning, hayfields and grassy roadside ditches offer ideal nesting grounds. The dense cover greens up early and lends itself to weaving. For a week the female builds, making hundreds of trips out and back along her hollowed runways, her long bill clamping twigs and straw she's gathered. For two weeks, give or take a day, she incubates her clutch of eggs. The young fledge 10 or 12 days after hatching but don't truly earn their wings until they're 21 days old. In the meantime their parents bring home caterpillars, beetles, hoppers, snails.

By a haymaker's reckoning, the ideal time to mow is just as, or just before, the forage plants begin to flower. The nutrients are at their richest concentration, and in a form that livestock have an easy time digesting. The peak time to harvest is the peak of the meadowlarks' breeding season. Home, sheared away.

Talk of biodiversity loss often brings to mind the plight of a few high-profile, individual species — legitimate concerns indeed, and galvanizing, but it's the larger weave that makes a world. Common grassland birds in their abundance share in the ongoing re-creation of a myriad of intricate relationships. They help to control insect populations; they pollinate plants, spread seeds. Insidious widespread population loss threatens entire ecosystems.

It might be the hay cutters shearing fields and ditches as the young are about to hatch or the conversion of pastureland acres to cropland or the several varieties of pesticide that diminish and contaminate the food supply and the soil where meadowlarks dig for bugs. Maybe it's the way fire suppression alters native grasslands or cats on the hunt or the growth of cities. Ornithologists cite any and all of these. With a loss of roughly one per cent a year, we can almost pretend it isn't happening — until, that is, we consider the cumulative slide over half a century.

Let me note I leave my prints all over this much-altered landscape. My appetites and actions shape ecosystems far beyond the city where I live. I eat the food produced here, animal and vegetable. My home sits in a neighbourhood that once was open country. I fill a tank and travel roads that slice the prairie into squares. Beyond my hearing aids, I own dozens more devices and appliances manufactured far away and flown here thanks to fossil fuels. I use them by the day, the hour, the minute.

When the batteries in my hearing aids run low, a friendly voice inside my ear says, "Battery", and I have three minutes' grace before they die. Usually I'm prepared. Occasionally I'm caught without replacements, and I hear my quiet future. I sense how subtlety evaporates as others rally their best intentions, look me full in the face and speak in plain and trudging sentences — to ensure I understand and to be done with my repeated Pardon me? This happens all too often even when my batteries are running at full power. It is my job to track the intricacies of human beings in relation to one another, to know the shaded ways we speak of matters deep and searing. I need to hear it all, the kind and the generous, the base and the jealous and the angry, the subtext and subordinate clauses — for what's the use of a writer who's lost her ear for life?

But listen: words can be seen as well as heard. I still have books and magazines and the printed word online. My television's programmed for closed captioning, and I've invented a drinking game based on how often the swearwords I still hear the actors say are replaced with milder phrasing in the captions — as if a person with hearing loss hasn't lost enough already. But captions will enrich a story, too. Soundtrack noises other than dialogue are spelled out in parentheses, and so along the bottom of the screen I see (garbled chirping), (waking groans). These readings can render a solemn moment hilarious: (slurping, with teeth clicking against spoon). They can also, unexpectedly, deepen a moment that might otherwise seem ordinary: (door closes), (ticking continues). Wouldn't it be welcome if, at needful moments in real life, a knowing hand were to deliver a timely caption? A snippet written on the wall in case you're about to miss the moment: (fate whispers); (opportunity knocks).

What shall I gather for my catalogue of sounds against the day? My husband's 'Good morning'; the swish of grasses bending in the wind; the bright string of notes a meadowlark flings at the sky.

Nearly three billion birds — from 10.1 billion in 1970 to 7.2 half a century later. If a person were to begin counting the moment their life began and count continuously, they might not reach a billion over a good long lifetime. Numbers so large are beyond our ken. So break them into dozens, hundreds, even thousands, and multiply from there. An artist in Saskatchewan has begun to paint individual North American birds, quick small sketches, and she's calling on others anywhere and everywhere to do the same. Choose your medium. "Spread the seed as you may and we'll see what becomes of it."** The goal is 2.9 billion images. Hashtag #bringbirdsback, among others. There are no rules, but why not take her cue and start with post-consumer cardboard? Cut open a cereal carton; uncoil a tube once the paper towels are done; tear the lid from a box of tea. When I was a girl in a prairie town, I could open a box of orange pekoe to find a pair of tiny cards, full colour: Birds of North America. Collect them all.

* Kenneth V. Rosenberg et al. Decline of the North American avifauna. Science, 4 October, 2019:120-124. Rosenberg, from Cornell University, worked with 10 colleagues from research institutions across Canada and the U.S. to arrive at these estimates.

** Dawna Rose, artist, Saskatoon. Personal communication.

Jack Kyle and Ronald Reid. Farming with Grassland Birds. Ontario Soil and Crop Improvement Association, 2016

Cornell Lab of Ornithology, birdsna.org and allaboutbirds.org

Leona Theis writes novels, stories and personal essays. She has written a book of linked stories, Sightlines, and a novel, The Art of Salvage. Her essays have appeared in magazines in Canada and the United States. She has been nominated for a Pushcart Prize and won the 2006 CBC Creative Nonfiction Prize. Her most recent short story appeared in American Short Fiction and her novel, If Sylvie Had Nine Lives, where the protagonist is granted nine separate lives, for better and worse, was published on Sept.1, 2020 by Freehand Press. She lives in Saskatoon.

The winner of the 2020 CBC Nonfiction Prize will receive $6,000 from the Canada Council for the Arts, have their work published on CBC Books and attend a two-week writing residency at the Banff Centre for the Arts and Creativity. Four finalists will each receive $1,000 from the Canada Council for the Arts and have their work published on CBC Books.

The 2021 CBC Short Story Prize is currently open for submissions. The 2021 CBC Nonfiction Prize will open in January. The 2021 CBC Poetry Prize will open in April.