It weighs almost nothing when I place it on my palm. Left there, it would soon become blood-warmed, almost to the temperature it had when it was alive. I'm holding an owl's skull. Or, to be more exact, I'm holding the skull of a long-eared owl (Asio otus). The bird it was part of died fifty years ago, caught in a cull of crows in a small wood in Northern Ireland. The perpetrators fired indiscriminately into the trees after dark, when the crows were roosting. I found the owl's body lying among the intended victims—the ground littered with telltale shotgun shells, their orange cases peppering with garish, unnatural color the dull scatter of feathered bodies lying among the leaves. I lifted the owl gently, cradling its limpness, and took it home.I kept two of the primary wing feathers, their surface furred with velvety down, their leading edges delicately serrated, like fine-toothed combs. These adaptations channel and hush the passage of the air and allow the owl to fly with deadly silence, giving its prey no warning of a predator's approach. Having put the feathers aside, I sheathed the owl's corpse in a sarcophagus of wire netting and buried it in the garden. I marked the spot with a piece of slate, pushed into the ground like a miniature headstone, the date of burial scratched across it. After ten weeks I dug it up. The detritivores had done their work, little grave robbers of the flesh. Only the skeleton was left, safely immovable within its cage. I cleaned the skull with diluted bleach, rinsed it, then left it in the sun to dry and whiten. I've kept it ever since.I realize this may seem macabre. Isn't a sloughed-off body part a distasteful—even repulsive—souvenir? Those who see it thus would shy away from touching it. If their fingers brushed against it accidentally, it might spark enough disgust to make them want to scrub their hands, or even shower, rid themselves of a sense of dirt, pollution, death. To me, it is a treasured token of a time and place I remember with great fondness. Far from being revolted by its corporeality, I marvel at the skull's fragile beauty, at what it once contained, at what it is.I like to weigh it in my hand, rekindle in my imagination the story that's invisibly imbued in it. Once, this husk-like remnant was the fortress behind whose walls a brain lay, protected, pulsing with the energy that vivified it. This was the bony cockpit from which a flood of sensations was savored and controlled as life's currents thrummed through the assembled cells, their pulse and voltage aligned in precisely the patterns needed to fit the niche of existence the bird occupied, carved out with exquisite particularity over the millennia. Although this relic is so light it feels like almost nothing, it carries a heavy cargo. I hope the reliquary of words I'm making for it here can contain and convey the electricity of wonder that I still feel crackling around it.Thornybrook Wood, County Antrim.I've changed the name of course, disguised the location, wary of leaving a trail for egg-collectors—or the merely careless curious. Once comparatively wild and rarely visited, as the Belfast–Lisburn conurbation continued its advance, engulfing countryside with a spread of roads and houses, the proximity and density of people increased. Soon it came to constitute a threat. Places like Thornybrook Wood are vulnerable. When I went there as a teenager it was rare to encounter anybody else—except an occasional, solitary angler fishing for brown trout in the nearby lake. Part of what made the shooting of the owl so shocking was its testimony of human incursion into this unfrequented place. The litter of spent ammunition was unwelcome evidence of other people's presence in what I considered, I know unreasonably, to be my wood.This was somewhere I got to know with the intimacy of spending unhurried hours there, just being in the place, listening to its sounds, attentive to its sights and smells, savoring its tastes, feeling the sun upon my skin, and the smooth, warm suck and tug of mud as I waded through the marshy ground around the lake, searching for orchids, or to reach a moorhen's nest. I can remember, as if yesterday, the wind shushing through the bulrushes, rippling the water with its breath. I remember, too, the sense of expectant wariness I felt the moment I stepped into the wood itself, knowing that the trees enclosed a little kingdom set apart from the adjoining fields and populated with its own watchful denizens.It took an hour to cycle to Thornybrook from where we lived. In those days, traffic was infrequent. I'd see a dozen vehicles at most once I'd left the town. The wood covered an area of several acres, cladding with its mix of deciduous trees and conifers a small rise of land that was bordered on one side by a lake and on the other by a river and marshy fields. Standing at the edge of the wood and looking across the rural panorama stretching toward the distant summits of the hills above Belfast, there were only a few scattered farmhouses; most of the outlook was the green of fields and trees and hedges. The area was rich in plant and animal life. It had a profusion of wildflowers, many species of bird; hares were a frequent sight. There was always evidence of foxes and badgers in the wood, and hedgehogs, weasels, stoats, and otters were often glimpsed. Summer brought an abundance of insects. The dragonflies were particularly striking, and I saw butterflies and moths there that I've not seen anywhere else. For me, it was a special place.In fact, when I think about it now, I'm tempted to delete “special” and write “magical,” or even “sacred.” Thornybrook generated a sense of being part of a fabric of life that was woven with a richer, brighter mix of thread than anything the town could offer. I felt more alive there. Though I know it had no grandeur, wasn't anywhere of note, possessed no special features that would warrant mention in a tourist guidebook, to me these rough acres of the County Antrim countryside possessed a rare beauty that touched me far more deeply than any of the world's famous picturesque places. The reputation of such places drew me to visit in the years ahead, but they always left me feeling disappointed, curiously empty, let down by the somehow run-of-the-mill splendor of their vaunted scenic-ness.I'm not sure if I can explain Thornybrook's impact on me; it's something I don't fully understand myself. But a key factor was surely that my own psychophysical season made me susceptible to what I think of as the spirit of this place. It felt like the isobars that controlled my inner climate swirled their way outward and became comfortably entangled with Thornybrook's, inner and outer weathers falling snugly into step. I explored the area in my early teens, when the fluctuating energies of adolescence were at their peak. Enthusiasms, interests, passionate attachments and dislikes surged through me with disorienting strength. Being in the wood I felt anchored, grounded, as if this was somewhere the voltage of my youth could safely earth. And as it did, a reciprocal but calming current seemed to flow into me from the place itself. There was a strong sense of connection, even entanglement—of land answering flesh, water and blood singing together, pulse beating synchronously with pulse.I hope this image of reciprocity at least hints at what I felt. It was as if I became benignly sutured to the place, my sense of self running its tendrils on into the trees and field and hedges, and they, in turn, giving something of their nature back to me. Watching sticklebacks and minnows in the sun-warmed lakeside shallows; climbing a spruce tree to find a sparrowhawk's nest; watching a heron hunting frogs; listening to a cuckoo calling; being startled by a snipe taking off at my feet; encountering a family of foxes at dusk; hearing bats and seeing their shapes flitting wraithlike through the dark; and, yes, lifting a dead owl from amidst the crows and leaves and cartridge cases—these and countless other interactions with what happened there kindled a sense of communion, of something flowing from the land to me and back again. One of the reasons the owl's skull has become such a potent talisman is because it's a token of this sense of intimate melding: an unlicensed, outlaw Eucharist.Though the skull is empty now, the shape of this fantastical container holds in its curves and hollows sufficient prompts to nudge into mind a picture of what once was here, held securely in its place, cradled in this little crucible. Sometimes I think of it as a kind of haunted house, its tiny chambers still ghosted with the presences that used to occupy it. Chief among them are the eyes—possessing, in life, striking orange-yellow coronas rimming the black irises. All that remains to suggest them now are the two massive hollows on either side of the skull. These, and the large ear cavities behind them, are testimony to the exquisitely acute sensory array brought to bear in hunting. The long-eared owl, as John Burton notes in Owls of the World: Their Evolution, Structure and Ecology, “is one of the most nocturnal owls in the world.” Accordingly, their eyes are designed to operate in near total darkness, their ears calibrated to detect with pinpoint accuracy the rustle of tiny movements in the dark. The left ear-opening is set slightly higher in the skull than the right one, an asymmetry that further enhances the bird's skill in directional location. Sounds reach one ear fractionally sooner than the other and the time difference provides a kind of aural pincer of extraordinary finesse. It lets the owl locate where a noise has come from with millimetric precision. In The Secret Life of the Owl, John Lewis-Stempel estimates that their hearing is honed to such a pitch that “owls are capable of detecting time differences of as little as 30 millionths of a second.”Looking at the skull, I'm struck by the fact that it's the apportioning of spaces, the relative size of the emptinesses it encloses, that's as suggestive of the bird's nature as any solid structure—though the hooked beak, still with a cuticle of dark, horny matter sheathing the white bone, clearly announces predatory function in its shape and sharpness. Behind the eye sockets and the cavities for the ears, the quayside to which these organs were once anchored, there's the gently domed occipital bone, the housing for the brain. There are openings between it and the eyes and ears, the bone plating of the braincase pierced with apertures, showing where dense cablings of nerves used to run. At the skull's base is the largest aperture of all—the foramen magnum—the carriageway connecting brain to spinal cord.After diverging from their common reptilian ancestor millions of years ago, mammalian and avian brains followed slightly different structural routes. In mammals, intelligence resides mainly in the cortex. In birds, it's sited in what Frank Gill—in his magisterial textbook Ornithology—calls “an alternative and unique feature,” namely, “the hyperstriatum and associated Wulst.” I put my finger to where that would have been, the spark of intelligence burning just behind the delicately crafted bulges of the bone, hard beneath my touch, but wafer thin—an almost translucent chrysalis.The visual and auditory spaces outlined by the bony tracery of the skull—the enormous empty sockets, and behind them the asymmetrical coves for listening—beckon back eyes and ears. Prompted by these cephalic cues, and by what I remember from watching living owls, it's not hard to picture the skull filled with a brain again, enfleshed and feathered, part of a breathing, moving bird. It stretches out its wings, looks at me with its strange, yellow-circled eyes and flies silently away, to hunt in my store of memories.The owls were a key ingredient in the enchantment I felt Thornybook Wood possessed. Knowing that it was home to these rarely seen nocturnal creatures enhanced the spell the place exerted. The fact that the rhythm of their existence was played out here, a long-established presence, bestowed a kind of secret pulse. In taking it—by occasional sightings, by finding a dropped feather, by collecting owl pellets—I felt attuned to the music of the place. The owls played a cadenza that you had to listen hard for, but once your ear became attuned and you learned to recognize its notes, they exerted a siren allure. The virtuosity of their lives is breathtaking.I spent hours at dusk and nightfall crouching motionless, concealed in the hawthorn hedge that edged a field facing that part of the wood the owls favored for their daytime roost. To see their large, silent shapes take form as they slid from the trees and flew low and silent across the grass was something I found thrilling each time I witnessed it. Once, one flew straight toward me, level with my face. It banked and curved at what seemed like the last moment, only seconds from collision. When I whipped round, I was in time to see it disappearing across the next field that stretched out behind my hiding place.In daylight I searched for pellets—owls swallow their prey whole and later cough up what's indigestible in pellets containing fur, feather, bone, and the shiny chitin of beetles’ wing cases. Sometimes I found fresh pellets clumped telltale under a roost so that, looking up, I was able to make out the pale shape of an owl sitting quite still above me in a tree, its body pressed close against the trunk. Once the eye learns to pick it out, to read color instead of camouflage, the plumage is beautiful—an intricate mix of subtle patterns, interweaving browns and creams and buffs. I've climbed to nests—untidy affairs without evidence of crafting, little more than rough, twiggy platforms provided by the old nests of other birds. I've seen eggs—white orbs, improbably pure and perfect in their ramshackle surroundings, gravid with the promise of new life. And I've exchanged looks with owlets, blinking like tiny aliens as they sit, still flightless, in the high branches beside the nest, improbably strange-looking creatures, covered in down, the huge eyes and tufts of feathers starting to show through, making them seem both weird and comic. I've dissected pellets and worked out the owl's diet from the remnants left in these tiny ossuaries, laying out their load of bones and identifying them by matching them against remains held in labelled museum collections. But by far my most striking memories of Thornybrook are of seeing the owls hunting, watching their ghostly forms materializing like a kind of solid darkness in the half-light of dusk. In those days, in that place, I was attuned to owls, which meant I was greatly saddened by the waste of losing one so casually, so pointlessly, in the ill-considered slaughter of another species.It's impossible to be sure whether the skull belonged to one of the owls I saw hunting. Over the time I spent at Thornybrook, I had many owl sightings. It's hard to tell how many different birds that involved and whether this skull was once part of one of them. One long-eared owl looks just like another; there are no obvious differences between the sexes, though the females are slightly larger than the males. Usually, my sightings were only momentary and often in poor light, so that even if there had been slight individual variations in different birds, they'd have been effectively invisible. Most years I found a single nest (others may have eluded my search). One season I found two—but that doesn't necessarily mean much in itself; a pair may move from one nest site to another. Though John Sparks and Tony Soper—in Owls: Their Natural and Unnatural History—say that long-eared owls sometimes “form communal roosts,” I've never seen more than two adult birds together at the same time, though I did once see four juveniles. I don't know how long the fledged young stay in the vicinity. Nor do I know how often nonresident owls passed through the wood, looking for food, or mates, or perhaps just blown off course in difficult weather. I don't know what the typical hunting range of a long-eared owl is. Perhaps Thornybrook was regularly visited by fly-ins from elsewhere. It could have been one of those that had the ill luck to be caught in the night-time massacre.Despite these uncertainties, I think the strong likelihood is that the owl I found dead among the crows was one of those I'd seen alive. So when I balance the skull on my palm, examine its structure, muse about its story, I often wonder if I featured in it. Did I play a bit part in its drama? Did this now-fragile receptacle once hold within the maze of its living brain an image of my teenage self? Did the ears pick up my footsteps, the eyes take in my shape? I find it curiously pleasing to think that here, within this bony chamber, an awareness of my presence may once have flickered across the bird's notice, something of me translated into nerve impulses speeding through the brain. It's intriguing to speculate about how I'd register on an owl's sensorium. I don't know how a human shape or human noises—breathing, footsteps, cough and rustle, laugh and voice—would be read by this secretive nocturnal predator. How I would have appeared to it would almost certainly not be in any form I'd recognize as me.Much of the skull's magnetism, what charges it with the significance it has, stems from my sense of it as a token taken from somewhere that was pivotal in my growing up. Somehow it still seems imbued with the flavor of the time I spent there. I know there's nothing left in it; its emptiness is quite complete. This flimsy relic enfolds within its fragile walls only the nothingness of vanished tenure. Yet for me it carries a precious, invisible cargo. When I hold it, it's as if its vanished eyes and ears pour back into my grip a distillation of the sights and sounds they gathered as they scanned the contours around Thornybrook. The skull provides a kind of spyhole, a magic lens that lets me see across time and space to zero in on Thornybrook Wood as it existed, unspoiled, half a century ago, and on me as the youth I used to be, just emerging into adulthood.I sometimes think of the owl's skull as a kind of space probe, launched into the little planetary system of Thornybrook Wood and its environs. For the duration of the owl's life, obedient as any satellite, it gathered data from this place, sifting through the signals that its senses harvested as they netted what pulsed out from the fields, the trees, the lake, and the bodies of prey creatures. Reading the input that it garnered, the owl settled into its daily—nightly—orbits, held in the cradle of life offered here, in this place, at that time, in a particular manner: the niche that sustained it. The ill chance of its death—being caught in the cull of crows—again points to its perfectly crafted adaptations for nocturnal hunting. As that doyen of ornithological photographers, Eric Hosking, puts it—in his autobiography, An Eye for a Bird—“in the dark this owl is able to fly safely through dense forests, with intertwining branches.” Had it not been flying through the trees when the cullers were firing into the branches, the only bodies I might have found would have been crows.Though the individual owl concerned perished half a century ago, this skull its only remnant, I hope that other owls—perhaps the descendants of this one—still occupy that niche. I know a lot has changed at Thornybrook, that human encroachment has massively increased, but I hope—perhaps unrealistically—that enough remains to provide a refuge for these beautiful birds. If they've gone it would be another sad impoverishment of place. To grasp what their loss entails, think of what these birds represent beyond the individual feathered forms we see roosting in a tree or flying through the night. Every individual looks back to the breeding pair before it. Each bird I saw at Thornybrook is the present point on a bloodline that stretches back for millions of years. The “oldest known record of an owl,” says John Lewis-Stempel, “is from about 58 million years ago.” Through that stupendous span of time, impulses have traveled along owl nerves, receptors of a barrage of information from the world's different habitats. Those impulses have been sifted, honed, and organized to create the diverse patterns of life of the many owl species that developed, Asio otus among them. Think of the accumulated messages passing from owl eyes and owl ears to owl brains, think of the impulses coursing through the inner kingdom of the owl, commanding talon clutches, beak yawns, wing stretches, glides, pounces on prey, and coughing up of pellets. Think of the time taken to issue in these different forms of life, to carve out their patterns, to exactly fit their niches. Then think of it snuffed out. Each individual bird is astonishing enough in its own right, in its single life. Seen as a fingerprint upon the earth of the history of its kind, it's so extraordinary it appears miraculous.I know that if I closed my hand and squeezed, even gently, the skull would shatter. The living bone would have possessed robust tensile strength. But severed from life's throb and fizz it's become a brittle husk. It has about it now an air of eggshell fragility. Sometimes I think it would be best to take it back to Thornybrook, pulverize it in my hand, and let the wind blow the dust and fragments back into the embrace of the place that once sustained it. But I value it too much to give it back. Nor do I wish to visit Thornybrook; I have no wish to see a place I loved as what I fear it may be now. Judging by what I saw the last time I was in Ireland, several years ago, it's well on its way to being denuded of its specialness. It was littered and besmirched by overuse. I saw evidence of careless tree felling, hedges ripped up, fields made into building sites, and everywhere you looked there were clusters of new houses. The land was thread-veined with roads not there before, riven with traffic noise, the wood become a haunt of too many dog-walkers.So the skull sits on my bookshelf, acting like a tiny beacon that marks the features of a now almost-mythical-seeming coastline. It pulses out a signal of a kind of phantom geography, hinting at the contours of another time and place, and a way of being that's under threat, or maybe vanished already. Despite its dryness, it acts like a kind of reservoir, holding accumulated sensations and flooding the imagination with memories, remembered panoramas, images, ideas. As well as registering some picture of my teenage self, did the skull once hold the clatter and din of the army helicopters that often flew low over the wood? How did such a monstrous, alien noise impinge on hearing sensitive enough to catch the rustle of a pygmy shrew and pinpoint precisely where the movement came from? Did the owl's night vision glimpse the furtive figures of terrorists hiding arms at the abandoned farmhouse, later raided by police, or see them lying in wait to spring an ambush? Northern Ireland's Troubles were raging at that time. They foisted on remote, unfrequented places like Thornybrook a dark tenancy as secretive as that of owls, but far from welcome.The owl's skull often nudges into mind a picture of the moment that the bird was killed. The sound of gunfire would have carried across the lake, a loud intrusion in the quiet of a peaceful place. If I'd been in the wood that night would I have heard the rain-like pitter of lead shot ripping through the leaves, or would that deadly sound have been masked, overlaid with the cullers’ shouts and the loud detonations of their shots as they fired into the trees? Would I have heard the repeated thump of feathered bodies as they hit the ground, like giant cushioned hailstones? What was the last sensation that registered in the owl's brain, encoded in the network of nerve impulses that flickered through the warm tissue that once filled this skull? The noise, the shapes of people, the impact when it fell? A sense—however such a sense might be mapped and parsed within an owl's cognition—of bewilderment, disorientation, terror? Trying to picture the last spark of awareness that shimmered through this bony container in my hand makes me think about the first moment of consciousness hosted within it. Would it have been a sense of swaying and warmth, as the embryo neared hatching in the egg, the nest rocked gently in a windblown tree, the adult bird's body generating an incubating heat? Between these two points, first and last sensations, the beginning and end of life, what symphony of sights and sounds played through the skull's now emptied concert hall? And echoing this question on a species scale, what were the first sensations that could be attributed to Asio otus? What will be the final ones in the last surviving members of this bloodline? And what—cumulatively—does the music of their saga sound like? What does it all amount to?The metaphor of music calls to mind a Scottish expression, “kist o’ whistles.” It means a church organ. A kist is simply a chest or large box. Originally, “kist o’ whistles” had a derogatory, mocking ring to it. But as the term passed out of common parlance and into literary use, that negative slant evaporated. I first heard it years ago, when I fled Northern Ireland's violence to live in Scotland. “Kist o’ whistles” made an instant appeal. I just liked the sound of it. It's not something I would have thought of using until now—for me, it was more an etymological curio than part of my working vocabulary; a quaint-sounding term rather than a useful one. But it surely fits the owl's skull beautifully. For is it not a treasure chest of whistles? The intimate array of microtubing that once filled it, threading the brain's tissue with veins, arteries, capillaries, nerves, is like a complex array of living organ pipes. I warm to the idea of the skull as a bony musical box sounding out the intricate toccatas and fugues of owl life. The way kist is used as a verb adds to the sense of fit. To kist a body, or kisting a body, is to coffin it—so a “kist o’ whistles” not only catches the sense of the owl's music, and the skull's boxlike containment of it, it also taps into the funereal thread of the story: the somber note of death. And the connotations with church and sacred music are also ironically apt—because I always found Thornybrook and its owls had far more sense of numen than I ever felt sitting in a hard-backed pew, surrounded by the niceties of conventional faith.The other association that surprised me when I began to write about the skull, coming back to mind as unbidden as a “kist o’ whistles,” is something from a fifteenth-century medical treatise, the Hortus Sanitatis. The title means “The Garden of Health” and the book is a compendium of supposed cures. It provides a wealth of information—much of it dubious—about the medicinal use of plants and animals. It includes remedies based on the body parts of a whole range of creatures, both real and imaginary. One cure for insanity suggests placing an owl's ashes on the eyes of the person afflicted. Perhaps if the reliquary I've written here has any use, it lies in the hope that the words it contains might act like ash, fall on afflicted eyes, cure them of the lack of vision that has allowed us to sleepwalk our way to the loss of so many Thornybrooks.