At some point during his last lap of breaststroke, before he transitioned to front crawl, he thought of Kat's field notebook. The one he could have told her about but didn't. It hadn't been an active choice on his part, but just that in the nowness of packing boxes, in the lists of mine and yours, he hadn't given it much thought. He might have told her, might have been honest about the fact that a small spiral notebook filled with her script accidentally remained in his possession, but he didn't. He might have sent an email. Might have texted her, along with a photo, "This yours?" he could have asked, just like she had, yesterday, about the paring knife that had once belonged to his mother. "Does she want it or can I keep?" Sam texted back, "its urs." Kat had been the one who cared about knives anyhow.

Instead of returning the book to her, he'd opened it last night and read it in its entirety. Sitting on his side of the leather couch they had both hated, but had inherited from Kat's cousin, he devoured her lists upon lists of birds. Before the days of eBird, before they'd agreed to merge their lists, Kat kept meticulous track of all her sightings. Sometimes she wrote the Latin binomial next to the common bird name, a few times she added a drawing, a distinctive field mark. Without thinking he recited the second declension paradigm to himself, starting with servus, as he had done, methodically, every day of his introductory Latin course. He looked up the collective noun for all those bird names he unintentionally learned. A squabble of seagulls.

The lists read to him like incantations.

Sam couldn't trace where the end began exactly, but now that they were inside of it, he couldn't stop its momentum.

Sam read that on January 7, 2010, Kat had been at Sunnyside Beach and had seen a FOY Iceland Gull in addition to the requisite 65 or so Ring-billed and Herring Gulls. A year before he had met her. A year before Sam had first heard someone use the term FOY, which he had to Google to learn that it was as banal as first of the year. This was before he knew that there existed so many variations of seagull, before he'd ever stopped to contemplate the universe of Laridae. Sam remembered thinking, when Kat told him about her pseudonymous blog, where she called herself Gull Gal, that a world where there exists a person who counts and writes lists of gulls for no other reason than to keep track was a strange and curious thing.

Before Kat, Sam didn't really have a passion. He woke up, swam laps in the pool across the street, showered, biked to the university and settled into his office, filled with volumes about Soviet history and art. He was writing a book about Tatlin and was researching the architect's peculiar self-flying machine, called Letatlin, a play on his name and the Russian verb letat, which means to fly. The morning after he'd come across an article about how Tatlin watched seagulls for months before designing his flying machine, he met the new library tech, Katya Levitan, whose sweatshirt had an enormous bird on it.

"I'm into flight too," she said, handing him his inter-library loan requests.

"I'm Sam," he said, extending his hand.

"I'm Kat. But I prefer birds to machine-operated movement."

"Tatlin was somewhere in between."

And so it began. Soviet avant-garde flying machines, aviation heroes and birds. He could pinpoint the moment it started, but not the moment it ended. Only he knew once it was over. He knew once the imperfective verb form — the one that's in motion — had transformed into a perfective one, already finished. Sam measured time in verb forms. The ones that reflect the passage of time and aren't translatable in English without a periphrasis. He dwelled in grammar.

"I dropped the 'ya' a few years ago. I'm just Kat."

"I wasn't wild about the 'uel' either and just went for Sam."

They laughed.

Or had he fallen for Kat because she shared a last name with Isaac Levitan, the painter he'd written his senior thesis about, the Wanderer who died young, as he liked to summarize his project. The friend of Chekhov's that nobody had ever heard of. His parents wondered whether he'd switched his major to Judaic Studies, based on the subject of his thesis. But Sam wanted to explore how writers responded to the visual arts and once he saw Levitan's moody autumnal landscapes, he knew that Chekhov's melancholic prose must have come from somewhere. Later, he came across Babel's definition of himself as a person with "spectacles on his nose and autumn in his heart," and wrote "see Levitan" in the margin, the name underlined twice.

And then he met this Kat who loved birds, which didn't make much sense to him because he had always thought of cats as predators of bird. Yet he couldn't get the semantic dissonance out of his head.

She must have loved the idea that she wouldn't have to translate for him when he met her mother. Kat liked that he could pass for Russian without having to be Russian. Not everybody brokered that skill. And still, Bella was initially skeptical.

"Does anybody even learn Russian these days? It's not the axis of evil anymore." She had a point. Enrolments had been dangerously low the past could of years. Sam hadn't recognized the importance of geopolitical strife when choosing his field. For him, it was more of a calling. He fell in love with Russian verb forms and case endings. Everything his classmates couldn't stand, his inner grammarian adored. The imperfective verbal aspect, which implied a repeated action, versus the perfective aspect that signaled a finished event. The nuance of grammar had him hooked since day one. But that wasn't something Bella would understand.

"Let him do what he wants. He loves it."

"You should have met a programmist. It's a real profession."

"Sam has a good job."

"All I'm saying is it wouldn't be natural for you to be the breadwinner in the family."

Had the unraveling begun when they saw the Great Grey Owl together just north of Whitby and he went back to the car while Kat stood there, mesmerized, imprinting the moment in his mind. Back in the car, he graded papers for the following day and waited for her to finish looking. She'd asked him twice to come out and see how the owl dipped down to catch a rodent, wanted him standing next to her while the bird mauled the minuscule vole to death.

Twice a week, Kat took flying lessons. Not literally, but she had enrolled in a ballet class to see what it would feel like to be more buoyant, perhaps to soar. Sam only saw her dance a few times, when the studio blinds were up and he watched her flutter in changements and échappés, just slightly above the ground. There was no soaring, no extravagant leaps, but he detected seconds of Kat airborne, her face beaming. Was that when she started imagine she'd fly away?

Their first date had been unremarkable. A solemn movie about someone who suffered from locked-in syndrome, was entirely paralyzed and could only communicate by blinking. Why he'd chosen the movie he could not recall, but rather than admit it wasn't her thing, Kat just fell asleep. In the theatre. He'd never seen anything quite like it. For their second date, Kat took him birding. He feigned interest in the ducks though her description of the Red-breasted Merganser's "Edward-Scissorhands-hairdo" took him by surprise. Kat had a way with words. He spent his entire days crafting sentences, and yet that isn't something he'd ever come up with. He hadn't even noticed plumage until Kat referred to it as hair.

He found the list of their bird sightings for that day in her notebook and noticed she'd drawn a heart next to the date. They'd seen 20 species of waterfowl that day and all he could remember was the Edward-Scissorhands bird.

Sam found a list from a trip Kat had taken to Arizona, to the Chiricahua mountains, shortly before meeting him. One day, at Whitewater Draw, she got five Roadrunners, 70 Yellow-headed Blackbirds and approximately 30,000 Sandhill Cranes. Half-way between the Chiricahua National Monument and an old copper mining town called Bisbee, he imagined her standing against the backdrop of an intense southern Arizona sunset, the kind where the sky is drenched a slowly modulating palette of pinks. He now realized he'd never asked her whether she'd travelled there alone or with company.

They'd lived together long enough to decorate the apartment in birds and Soviet art posters. Next to Tatlin's utopic Monument to the Third International, the building that would have dwarfed the Empire State Building, they'd hung a picture of a Great Black-backed Gull, the largest, most aggressive in the Laridae family, the gull that could take down a puffin if need be, the gull that Kat had once put a band on, with the help of her supervisor at the seabird colony where she'd once spent the summer.

For Kat's birthday the second year they were together, Sam had undertaken a project of bibliographic proportion: he entered all her pre-eBird sightings onto the website, which involved sorting through her field notebooks and the lists she kept on her computer, eliminating the duplicate versions and ensuring that dates, weather, and locations all added up. The task reminded him of his first research assistant job, when he assisted in the compilation of an index and bibliography for a book about early Christianity, which he found both terrifying and heartening. He loved that job – making lists with headings and subheadings, cross-referencing titles. He felt in control of an entire world. The professor he'd worked for had been impressed with his diligence, the way he stalked references even in languages he didn't know. And then just as Sam decided to apply to graduate school, the professor whose index he'd compiled, the virtuoso prodigy, the youngest tenured history professor at the university, died of a sudden and massive stroke. After that experience, he always hired a student to work on his indexes — he was afraid of the karma.

After they'd gone for a walk along the lake, to visit the resident Snowy Owl, Kat entered their sightings on eBird.

"How did my checklist number suddenly increase to 2340? Is there a glitch in the program?"

"I doubt it." Sam smiled.

It had taken him months. He loved doing it and felt like he was getting to know Kat's past. He travelled with her to Israel, where she saw Hoopoes everywhere she went, and found a Little Bee-eater on her last morning in Eilat. He followed her to Point Pelee, where she stood in the pouring rain during her first fallout and saw 25 species of warbler literally at her feet or in the bushes at eye level. He saw lists from southern Ontario and realized that they had even overlapped in Algonquin Park one weekend when he and his then-girlfriend had rented a cottage on Hay Lake, and Kat and someone named Brian had fed Grey Jays just down the road from them. The bird that ornithologists had recently re-christened Canada Jay, but back in 2016 it was still a Grey Jay. Her notebook even had photos of Kat's disembodied hand with a bird perched on it. A bird with two coloured bands on its right leg, part of someone's study.

"You didn't," Kat said to him, shaking her head and smiling at the same time.

Or was it the time they'd gone to Niagara one weekend in late November to find the reported Black-legged Kittiwake and stood facing the wind for two hours. Kat got the Franklin's Gull and a slew of Bonaparte's but no kittiwake in sight. Without thinking, Sam suggested lunch.

"But we came for the Kittiwake."

"Maybe it has other plans?"

"You're just repeating what I say. It was reported. It's got to be here."

"You've already seen Kittiwake, haven't you?

"That was in Newfoundland. I want to get one in Ontario."

Sam made the mistake of saying, "It's just a gull," and with that Kat turned around, walked to the car and didn't say another word. She checked eBird to see if the gull had been reported, but otherwise didn't speak to Sam.

"I didn't mean that gulls were dull, it's just that I don't get them." But he did mean it. Sam couldn't stand gulls and didn't understand the appeal of playing Where's Waldo while searching for them.

In they end they did get the Kittiwake, but when Kat entered the list on eBird she made a note about how they hadn't tried hard enough the first time, she had been distracted, that the bird is there for those who knew how to look.

All Sam knew was that they were together until they weren't. Somewhere between the Kittiwake and the Great Grey Owl a microscopic element of feeling shifted, the way a single vowel alters the meaning of a verb form entirely. Maybe we had rushed into things, Kat suggested. Maybe some time apart would clarify things. And the more they exchanged platitudes, the more they knew nothing would become more lucid, that they were searching for something the other had no idea how to give.

Sam entered all the sightings from Kat's last notebook on eBird. She was now up to 2457 checklists and a several of her sightings constituted rarities. Sam kept the notebook for a year, thinking that Kat might come back for it, but she never did. Sometimes Sam wakes early and goes to Sunnyside beach to watch the seagulls, hoping to catch a glimpse of her, to tell her that he travelled to Iceland for a Tatlin conference and that the first thing he asked the graduate student in charge of taking him around the Snaeffelnes Peninsula on his day off, apart from wanting to walk the perimeter of an inactive volcano, was that he wanted, if possible, to see a little gull that is apparently common in these northern parts, but one he very much regrets missing when it accidentally flew over the Canadian Great Lakes a few years ago, a Black-legged Kittiwake.

On the off chance that she'll search him out on eBird, he opens up a pseudonymous account called Laridaephile and submits his first checklist. A rough estimate of 2500 Black-legged Kittiwake huddled on the side of a cliff in Hellnar.

Julia Zarankin is a Toronto-based writer and lecturer to lifelong learners. She is the author of Field Notes from an Unintentional Birder, a memoir forthcoming with Douglas & McIntyre.

The winner of the 2020 CBC Short Story 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 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.