Tuesday, July 31, 2018

In Pursuit of Search Images

Among the first pieces of advice given a novice fossil hunter is that he or she has to acquire a “search image” of the prey, that is, fossils.  The hunter needs to have a mental picture of what is being pursued, not in isolation, but in context, in its natural environment.  It’s sound though simplistic guidance.  Search images are complex phenomena, involving myriad factors that are only mastered with time and experience.  There’s a rich literature about the creation of search images by many different kinds of animals, from humans to birds to insects.  It’s a literature that begins with the premise that “everyone searches all the time” (well, often enough for it to be deemed “all the time”).  (Miguel P. Eckstein, Visual Search:  A Retrospective, Journal of Vision, Volume 11, Number 5, 2011, p.1.)

I’ve been thinking about search images a great deal lately as I bide my time waiting for contactors (who usually don’t show – just one of the pleasures the owner of a ramshackle summer cottage enjoys during a “vacation”).  I have two ways to fritter time.  The first is one of those 1000-piece jigsaw puzzles.  Among my rules that render this a particular challenge is that the picture on the box lid must remain covered during assembly of the puzzle.

The table on which the puzzle is being assembled is only large enough to accommodate the completed puzzle, as a result we’ve filled the box lid and box bottom with pieces that must be sifted through repeatedly (yes, we could have brought another table top into play but, perversely, we didn’t).  It’s that aspect of this current effort that most brought to mind fossil hunting and search images.  I concentrate my labor on several different areas of the puzzle that are distinguishable primarily by their colors and patterns.  So, as I sort through the boxes of pieces, my search images apparently involve relevant colors (and shadings) and patterns, the orientations of those patterns, the shapes of missing pieces, but, I came to learn early in the game that I’m not looking for specific pieces.  Rather, it seems that I’m alert to pieces that might stand out, that are anomalous, matching one of several different search images, primarily those related to each area of concentration.  There’s a flexibility inherent in this process; the success of the effort doesn’t depend on finding a particular piece or kind of piece (beyond the initial quest for all of the straight edges).

I have described all of this as conditional because I don’t know what’s really going on.  Over time and as more of the puzzle gets filled in, I feel as though I’m performing a parlor trick – dipping into a box, rummaging around, and emerging with a piece that, lo and behold, fits somewhere.  It feels instinctive, automatic, not something that I think through, though clearly there are mental processes intimately involved.

The second way I’ve occupied myself while waiting is reading J.A. Baker’s The Peregrine (1967), a strikingly poetic paean to the peregrine, a predator which, when Baker wrote, seemed doomed in his England and, indeed, globally.  Baker’s high reputation is built on just two works, this one and The Hill of Summer (1969), which are intimate portraits of nature in his small piece of Essex, and which have led some to consider him “one of the most important British writers on nature in the twentieth century.”  (Mark Cocker, Introduction to The Complete Work of J.A. Baker (2010), p. 4, page numbers are for the eBook version.)  My search for the gestalt of the search image has been fueled by this book.

The peregrine falcon (Falco peregrinus) is probably best known for its high-speed stoop (the ornithologically correct term for its hunting swoop or dive) during which it can reach a couple of hundred miles per hour.  As one learns from Baker’s account, the stoop is frequently unsuccessful and is apparently sometimes engaged in playfully to stir up the local bird and small mammal population.

For a decade, Baker stalked the peregrine with a sense of urgency because he believed it was going extinct.  The book, which reads as the diary of single year, draws on his entire decade of observation and does not shirk from the killing business that engages the falcon, describing frequently the hunt, the kill, and the feeding.  (To be fully correct ornithologically, I should reserve the word “falcon” for the females of the species and “tiercel” for the males, but that just gets confusing.  Also, Baker often refers to the peregrines as hawks.)

What kept me enthralled by the book is Baker’s use of language, very reminiscent of Gerard Manley Hopkins and Walt Whitman, and, on occasion, William Shakespeare.  Words are objects to manipulated, albeit carefully, studied and used to their best effect even if that application breaks new ground.  But unlike the writers just cited, the scope of Baker’s interest is decidedly parochial, his intentions are grounded in the beauty and reality of his small portion of Essex
The territory in which my observations were made measures roughly twenty miles from east to west and ten miles from north to south. (p. 35)
Paradoxically, he generally shies away from identifying specific locations which means this parcel of land can be many such parcels – there’s a universality at work here.

He uses language to describe what he sees in as an evocative way as possible.  Here’s one opening to a diary entry.
High tide was at three o’clock, lifting along the southern shore of the estuary.  Snipe shuddering from the dykes.  White glinting water welling in, mouthing the stones of the sea-wall.  Moored boats pecking at the water.  Dark red glasswort shining like drowned blood.  (p. 56)
One of my favorite passages has hard-to-resist dinosaur imagery.
Fog hid the day in steamy heat.  It smelt acrid and metallic, fumbling my face with cold decaying fingers.  It lay by the road like a Jurassic saurian, fetid and inert in a swamp.  (p. 53)
His descriptions of the peregrines are sometimes dramatic and sometimes very simple and matter-of-fact.  He often treats the peregrine’s sky world as though it’s a water world, populated by marine life.  It matters not that metaphors are mixed, the result is moving and beautiful.
I expected the hawk [peregrine] to drop from the sky, but he came low from inland.  He was a skimming black crescent, cutting across the saltings [British term for coastal land covered by the tides], sending up a cloud of dunlin dense as a swarm of bees.  He drove up between them, black shark in shoals of silver fish, threshing and plunging.  With a sudden stab down he was clear of the swirl and was chasing a solitary dunlin up into the sky.  The dunlin seemed to come slowly back to the hawk.  It passed into his dark outline, and did not reappear.  There was no brutality, no violence.  The hawk’s foot reach out, and gripped, and squeezed, and quenched the dunlin’s heart as effortlessly as a man’s finger extinguishing an insect.  Languidly, easily, the hawk glided down to an elm on the island to plume and eat his prey.  (p. 56)
And what of search images?  There is a recurrent theme in the book of how one finds the peregrine in its natural habitat, what one looks for, the signals and signs that mean the peregrine is near and, indeed, where it is.  It’s clearly a mental and physical process built up over a decade of close observation.

The person in pursuit of the peregrine must master a variety of skills.  Attention to detail is paramount for Baker, but so is an understanding of context and what the context does to one’s image of his or her objective.  Coming to the quest with a search image built on the pictures and drawings in guidebooks, or the specimens one sees in a museum, is to come ill-prepared.  Seeing the object in its environment, over and over again, is key.
The hardest thing of all to see is what is really there.  Books about birds show pictures of the peregrine, and the text is full of information.  Large and isolated in the gleaming whiteness of the page, the hawk stares back at you, statuesque, brightly coloured.  But when you have shut the book, you will never see that bird again.  Compared with the close and static image, the reality will seem dull and disappointing.  The living bird will never be so large, so shiny-bright.  It will be deep in landscape, and always sinking farther back, always at the point of being lost.  Pictures are waxworks beside the passionate mobility of the living bird.  (p. 33)
Yes, it is universally true that the effective search image captures not what the entity looks like in isolation, but how it appears in the environment in which it is to be found – true for peregrines as for fossils.

Baker is attentive to the distractors in every scene, those things which might deflect him from his pursuit because they are similar to the specimen sought or because they draw attention to themselves for other reasons.  The distractors for the peregrine hunter, unlike those for the fossil hunter, are dynamic, reacting to the quarry.  Baker’s distractors can act as signals of the presence of the peregrine.  Obviously, when the myriad birds that populate the landscape suddenly react in panic or normally talkative birds go silent, one looks for the predator:
Bird to the north-east stayed longer in cover, as though they were closer to danger.  Following the direction of their gaze, I found the hawk skirmishing with two crows.  (p. 68)
An intimate knowledge of the expected is important, knowing what should be there or, perhaps, what should only be there makes all the difference.  It’s a quest for the anomaly.  Again, true for the fossil collector as well.
To find them [peregrines], one must learn the shapes of all the valley trees, till anything added becomes, at once, a bird.  Hawks hide in dead trees.  They grow out of them like branches.  (p. 54)
These then are among the critical attributes of the search images behind a successful quest for a peregrine, and, I believe, mostly relevant for fossils – construct a mental image of the quarry in context; know that context intimately; be alert to, but not misled by, distractors; and, above all, be attentive to anomalies.

Beyond the imaging behind the search, Baker also understood how compelling the search can be, even when the outcome does not spell the difference between life and death as it does for the peregrine.  Indeed, the fossil hunter, the peregrine hunter, and perhaps the peregrine itself, feels an exhilaration when a search comes to a successful conclusion.  Baker knew that feeling, I know it:
When the hawk is found, the hunter can looking lovingly back at all the tedium and misery of searching and waiting that went before.  All is transfigured, as though the broken columns of a ruined temple had suddenly resumed their ancient splendor.  (p. 31)
And he wrote of the compulsion that comes with, and lies behind, the search:
For ten years I have been looking upward for that cloud-biting anchor shape, that crossbow flinging through the air.  The eye becomes insatiable for hawks.  (p. 29)
I’ll close with an instance of how my insatiable hunt for fossils brought search images to bear in a somewhat unlikely place.  I’ve written before of the annual gem and mineral show that is held out here on the island.  This year, the number of vendors with fossils seemed diminished; a couple of old timers didn’t show.  I wandered around myriad tables covered with gems and minerals.  Overhearing conversations that start with, “Here hold this rock.  You can feel its power.”, I felt my enthusiasm for this search rapidly fading.  Then, as I glanced at a table displaying tray upon tray of gems, my eye was drawn to one tray partly covered by another.  Perhaps it was that disturbance in the otherwise orderly scene that initially caught my attention, but that was followed by a bolt of recognition – I immediately knew what that tray held:  fossil foraminifera shells.  Indeed, several dozen specimens of Nummulites sp., all at least an inch in diameter, were being offered for sale.  These came from Pakistan and likely from early in the Eocene Epoch, perhaps 56 to 48 million years ago.  Of note, Nummulites are commonly found in the limestone of the Egyptian pyramids and the ancient Egyptians used them as coins.  I’ve even posted on the shells of a similar kind of foram.  So, here below are several of the anomalies that drew my search that day to a successful close.

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