Tuesday, August 28, 2012

A Beast With Two Backs - The Gray Photo Deconstructed

In his landmark book The Monsters of Loch Ness (Swallow Press, 1976) University of Chicago Professor Roy P. Mackal wrote of the 1933 Hugh Gray photograph:

"I believe the picture is probably a genuine photograph of one of the aquatic animals in Loch Ness.  However, objectively, nothing decisive can be derived from this picture.  There is no apparent basis for determining which is front or back, and any such decisions must depend largely on what preconceptions one may have.  Nevertheless, the two protuberances along the waterline may well represent appendages (fore and hind limbs), and the outline at the waterline appears to show a horizontal sinuous undulation.  The importance of providing photographic evidence of these possibilities is not to be underestimated."

A distinguished research biologist, as well as being the first scientist to apply computer based statistical analysis to Loch Ness phenomenon data, Mackal was no easy pushover.  In his analyses of the Loch Ness "monster" surface photos then extant, he awarded his "positive evidence" rating to only three, including the Gray Photo, while ruling out even that most famous of Nessie pictures, the Surgeon's Photo by R.K. Wilson, a photo widely accepted as authentic by many people of the time.

Mackal's observations about the Gray photo were astute, but also rather remarkable considering the poor quality of the image he and every other researcher had to work with at the time.  Here is a scan of the Gray photo as it appeared in Mackal's book:



SOME HISTORICAL BACKGROUND

References to the Gaelic water horse tradition, and specific mentions of the Each Uisge or kelpie of  Loch Ness, the loch most frequently cited in conjunction with  the tradition, are scattered throughout historical texts written from the 16th century and forward.  A Pictish gravestone dating from between the 7th and 9th centuries depicts the creature, as may some earlier carvings.  The earliest recorded sighting of a "monster" in Loch Ness (or at least the River Ness, depending on one's source) details an encounter with the animal made by Saint Columba, while traveling through Scotland in the late 6th century on a mission to convert the Picts.  For a full account of the long overlooked historical tradition behind the Loch Ness mystery animal, I heartily recommend reading Roland Watson's book The Water Horses of Loch Ness (CreateSpace Independent Publishing Platform, 2011).

Despite the ancient and deeply rooted tradition that large, unidentified animals lived in the depths of Loch Ness, it's unlikely that few people outside the Highlands of Scotland would have paid the matter any attention if it had not been for one invention: the camera.

Around Sunday noon on the date of November 12, 1933, while strolling home from church, a local resident named Hugh Gray spotted something rise in the Loch, thrashing its tail and making a considerable splashing about 100 yards out from the spot where the river Foyers enters Loch Ness.  Gray's sighting was only one of many over the centuries, but what distinguishes it from all that came before was that he was carrying a camera, and used it to take the first known photograph of the animal.  He took five pictures in total, unsure if any would turn out amidst all the splashing and spray.  One photo did turn out, and along with Gray's story it was submitted to The Daily Record and Mail.  The Daily Record had the fortuitous presence of mind to submit the negative to several experts, including Kodak, all of whom agreed there was no sign of any tampering.  Of course it would have been highly difficult in those pre-Photo Shop days for Hugh Gray, a local aluminum company worker, to have engaged in trick photography, but it is all the better for us that the provenance of the original photograph and negative was being firmly established at this early point, re-enforced in subsequent years by the findings of those researchers who visited Gray.  Interviewed over the years by the likes of Constance Whyte, Ted Holiday, and Tim Dinsdale, Gray never waivered in the details of his story, and must be considered a highly reliable and even reluctant witness.

The Daily Record published the Gray Photo in December of 1933.  It was quickly picked up and repeated in The Daily Sketch, The Daily Telegraph, and newspapers across the world.  In modern terms, the story "went viral", and the modern, press-driven era of "The Loch Ness Monster" and its nickname "Nessie" had begun


HEADS OR TAILS?

The various versions of the picture as published by the press of the day can be found all over the Internet, and generally look no better than this:


And it was from reproductions like these, made from the original negative first being converted to half-tones, and then having had their contrast considerably tweeked upwards to darken and "solidify" the images for newsprint publication -- processes which inevitably subtract all fine detail -- that Loch Ness investigators have had to work for the past eight decades.  Back in the early nineties when I originally became interested in seeing if I could work out the morphology of the Loch Ness animal for myself, I put one of my first computers to work scanning images of the various photos from books, another process which in itself can lead to further lost detail and the introduction of visual artifacts that weren't part of the original photo.  One result was the reproduction of the Gray Photo from the Mackal book, found at the very top of this article.  The fact is that if you tweek and photo-shop any photo enough, you might start seeing Labrador Retrievers in anything, including the Mona Lisa.  (That Gray photographed a dog is a ludicrous and lamentable idea that itself went viral in the early days of popular Internet usage, and some renditions of the Gray photo floating around appear further retouched to deliberately bolster that ridiculous notion.)

Looking at these newsprint and book reproductions leaves little wonder why Mackal wrote "There is no apparent basis for determining which is front or back, and any such decisions must depend largely on what preconceptions one may have."  And yet there is enticing detail in even these images.  Coupled with Gray's testimony there can be no doubt we are looking at an animate, living object.  The part on the left is the clearest element of the image, and caught in the act of undulating as Hugh Gray described the tail to be doing.  There's not one but two pointed, fin-like structures arising from the top of this tail, if it's the tail, at the point it meets the main body, but then these fins appear to diverge into different directions -- which seemingly makes no sense.  This particular mystery is most evident in the higher contrast versions:


But if this is the tail, then where is the neck and head?  If one is working from the preconception that there has to be a long neck, then perhaps this is the neck, and perhaps those dorsal fins, if relaxed and hanging, would account for the occasional reports of a mane?  Following an assumption this is the head and neck, then the head is small indeed, absolutely miniscule in proportion to the overall size of the animal; it appears completely undifferentiated from the "neck" here, although there may be a couple minute features visible that could be eye slits or even little stalks (except that they only appear at the highest contrast and when the image is taken from a book; on this small scale they may only be artifacts of the printing process).

Also, if this is the neck, then the tail (which must be quite developed to serve as Nessie's means of reputed rapid propulsion) must be at the right hand end of the object, but there's no sign of it; could it be flexed down at an acute angle and fully below the waterline?  Conversely, if this element in the image detail above is actually the tail, then it's the neck bent acutely below the waterline at the right end of the object; that might make some sense if Nessie is floating on the surface dangling its neck below the waterline like a fishing line intent on snagging prey.  But if that were the case, all the splashing and tail thrashing Gray reported seems counterproductive to sneaking up on fish.

Other intriguing details in the total picture are the two white dots along the waterline where one might expect appendages to be.  F.W. Holiday studied the Gray Photo intensely, was one of the interviewers of Hugh Gray, and visited the spot from which the picture was taken.  In The Great Orm of Loch Ness (W.W. Norton and Co., 1968) he states his conviction these are indeed the parapodia of the Loch Ness animal.

And here is pretty much where further analysis of the Gray Photo was stalled.  There wasn't enough detail in any of these newsprint photos and their circulating reproductions to answer these questions.  Unfortunately whatever became of the original negative is unknown.  After nearly 80 years of study, not much more could be said.


A BOMBSHELL

In 2011, Loch Ness researcher and author Roland Watson wrote the definitive analysis of the Hugh Gray Photo in his article The Hugh Gray Photograph Revisited.  It is published at his blog, and it is mandatory reading for anyone interested in the Loch Ness animal, and the Hugh Gray photo in particular.  To quote Mr. Watson:

"It is best in these cases to get the most original image and as luck would have it another print came into the hands of Maurice Burton in the 1960s which were made from glass lantern slides in 1933 for E. Heron-Allen. Importantly, these contact positives were made from the original negative and represent the best untouched picture of what Hugh Gray saw that day."

Watson obtained this all-important picture, made from the original negative, from the Fortean Picture Library.  The full image used in Mr. Watson's analysis may be viewed in his blog article mentioned and linked to above.  In commenting on Watson's analysis, Aleksandar T. Lovchanski furnishes the information that Steuart Campbell deposited the glass lantern slide print with the FPL after obtaining it from Burton.  Therefore the provenance of the Heron-Allen version is rather well established, stretching back to the original negative.  It is only regrettable that this more definitive version of the Gray Photo was overlooked by so many researches for so long.

The Heron-Allen image contains all the detail lost in the press reproductions and their overwhelming contrast adjustments, and upon studying it Roland Watson made what few would contest must be the most important discovery in Loch Ness research in many years.  He found the head!  And it is on the right.

Having stared at the Gray Photo in books, having scanned it, enlarged it, filtered it, sketched it, and looked at it every way possible for about 40 years, I'm still a bit thunderstruck by this revelation.  But I am convinced that what Watson has identified as the head is indeed just that: our only known picture of the head of the unidentified species in Loch Ness.

At first this struck me as creating more problems than it solved, as like many I took it that Nessie had a long neck and a small head.  While I never subscribed to the Plesiosaur theory, I assumed that convergent evolution had resulted in an amphibian with an anatomy that followed the long-necked, fish-chasing body plan of a Plesiosaur.  Nature does not discard proven templates, and it was a design that served many species of aquatic reptiles quite well for millions of years.  But that has not proven to be the case in Loch Ness.  The Gray Photo is hard evidence that Nessie has a short neck, and a relatively large and fish-like head.

So swallowing my pride (and abandoning a pet theory of my own, which I might detail in a later post for nostalgia's sake) I set about having my own closer look at the Heron-Allen image. After all, if I'd been overlooking the head for 40+ years, the important question became: what else had I (and everyone else) missed?  If the details of the poor, over-contrasted press releases of the Gray Photo had been so enticing, how much more might we learn from the Heron-Allen version?  It needs to be taken apart and put back together, a project I decided to tackle soon after learning of Watson's find.

The first and most important contribution I spotted is the reason for the title of this post.


A BEAST WITH TWO BACKS

There are not one, but two specimens of the Loch Ness animal captured in Hugh Gray's photo.  (For the best look at the Heron-Allen image I again link you to an article by Roland Watson, The Forensics of the Loch Ness Monster.  You may click on his image there for a full-sized zoom on the Heron-Allen image.)

There are two backs (or dorsal lines) to follow if you trace your finger across the image from left to right, with the clearest example of this being between the two bright water sprays.  You may note that the back of the topmost or further animal becomes the top of the head Watson discovered.  This animal, the one furthest away, is also about one head's length ahead of the nearer animal, and the head of the nearer animal is hidden in the spray.

If you are using an LCD monitor such as on a laptop, start with the screen almost vertical and then slowly tilt it back while viewing the Heron-Allen image -- that's how I first spotted the second dorsal line.  Below is a smaller version of the image onto which I've drawn an overlay for comparison with the original.  I use hyphenated lines in the two places where spray obscures the dorsal line of the front-most animal, where the head of the front-most animal is hidden behind spray, and where the anterior appendage disappears below the waterline:



Let's examine, from left to right, what is visible here but has not been previously noted or explained by the high contrast press releases of the Gray Photo.

First is the tail.  Unlike Mackal, whom we quoted to begin this article, we now do have a basis for identifying the leftmost part as the tail, because the head has been identified by Watson on the right.  The caudal fins (not fin) were actually more evident in the high contrast prints.  If you capture the image and increase the contrast yourself, you can turn the Heron-Allen image into an exact replica of the press version minus the scratches (another bit of proof we're dealing with the original photo here.)  Turning up the contrast does increase some detail on the left side of the picture, like the caudal fins in my earlier close-up, while simultaneously ruining details such as the head on the right hand side.  But now that we've identified two separate backs, the reason for the mystery in my earlier look at the fins becomes evident:  there are two apexes to the "fin" because it's actually two fins belonging to two separate tails, one behind and slightly ahead of the other.  What may even be the tip of the second tail is visible protruding just left of the caudal fin of the front-most animal.

Working our way right, the next element of interest is the posterior appendage.  We now know it to be the posterior one, because we know which end is which.  In the original press publications of the photo both appendages appeared as mere white dots, but here we have quite a bit more to look at.

There actually appears to be a motion-blurred after-image of a flipper-shaped posterior appendage in the spray, making it look for all the world that this fountain of water was cast up by the rear appendage of the front-most animal.  What may be the edge of the appendage itself, slapping the water, appears at the waterline.  Alas this is not a great view of the appendage itself, but it's almost incontrovertible from this that Nessie has posterior appendages -- or at least this one does.

Moving further right along the waterline we come to the anterior appendage.  Second only to the head, this may be the detail most improved in the Heron-Allen image.  Instead of just a white dot, we have the upper joint of a limb meeting the body at approximately a 90 degree angle, then flexing downwards and sweeping back at a second joint point just before dipping below the waterline.  We cannot say if the termination point of the appendage is a flipper, a webbed foot, or another form because the end is below the waterline.  The few witnesses that have reported appendages in their sightings over the years have varied in their descriptions of flippers, webbed feet, and even hoof-like forms.

Accounts have also varied as to whether Nessie has both front and back appendages, but in this photo there is clearly a back appendage of some kind tossing up water.  Oddly though, whereas the anterior limb joins the body clearly above the waterline, the joint of the posterior appendage does not appear at all.  This is a mystery.  The animal (the front one) might be twisting a bit on its longitudinal axis -- there is considerable flexing in the body from the curvature in the waterline, a feature also less evident in poorer quality images.  The animal be turning its head towards the animal beside it.  Perhaps in the process of twisting its front half to the left, the attachment point for the right front limb is lifted higher than the attachment point for the posterior counterpart, which is hidden just below the waterline at that moment.

It may be worth mentioning at this point that aquatic amphibians, being neotenic and only completing partial metamorphosis do not always have equally developed front and back limbs, or at least do not always have equally developed appendages until the latter stages of growth.  In aquatic urodeles the second pair of limbs may be fully developed, partially developed, or totally absent in members of the same species (Mackal, 1976).

It must also be mentioned that, while the left-most spray of water appears to be created by the posterior appendage slapping the water, the same cannot be said for the right-most flash of spray; that must be coming from the left anterior appendage of the second or furthest animal, tossed towards us and over the head of the nearer animal.  That the two beasts are alternating front and rear water slaps like this is in itself quite interesting; water must be flying continuously; Hugh Gray reported considerable splashing, which must be taken to mean ongoing splashing, not just one instance of spray.

We end our tour of the Heron-Allen image at the right hand end, with Nessie apparently looking right back at us.  In making this discovery Roland Watson points out that even if the eye is not an eye, even if the mouth is not the mouth, the body of the animal clearly ends here in a blunt, conical shape above the waterline, and it casts a definite shadow of its own on the water.  Again I recommend his article on this, but for my part I'm fully convinced the Gray Photo is showing us the head of Nessie.

And I'm equally certain we have been looking at a photo of two of the animals all along.  But is this mating behavior?  Social behavior?  Some salamanders engage in a courtship dances when preparing to mate that consist of rubbing sides, splashing with their limbs, and thrashing their tails side to side.  Such behavior is strikingly similar to what Hugh Gray witnessed and photographed.  This is obviously one area where we'd like to know much more.


GRAY'S ACCOUNT VS. HIS PHOTO

At this point I can imagine skeptics protesting the likelihood anyone could be so lucky as to photograph a pair of Loch Ness Monsters at one go, as it's so notoriously difficult to get photo evidence for even a single such animal. Yet real animals often travel in pairs and small groups.  Even the most solitary creatures have to pair up on occasion if the species is to continue.  In fact the many reported sightings of multiple and varying humps are most easily accounted for by multiple animals.  If genuine, the P.A. MacNab photo taken in 1955 is most likely a picture of two animals as well (otherwise we're faced with a specimen over 50 feet long, which would be much less probable than two animals of 20 or 30 feet each.)

The strongest evidence that the creatures swim in small groups comes from the University of Birmingham expeditions (1968-1969) and their sonar experiments headed up by Professor D.G. Tucker.  On multiple occasions, the Birmingham researchers tracked large animate objects they estimated to be 20 feet long moving between the bottom of the Loch and mid-water, but never any higher.  Contacts included at least one pair, and on one occasion a group or pod of what they estimated to be at least as many as five animals moving together for an extended period.  They also clocked the diving speeds of the animals to be too great to be accounted for by fish.

(In all fairness it should be pointed out that there are other interpretations of the Birmingham sonar data.  Specifically that during some of the most pertinent readings, the thermocline was at its most reflective, and a surface craft had indeed passed through the area, the wake of which could have caused some spurious sonar reflections.)

The hardest thing about accepting the Gray photo as two animals was that Gray himself never said anything about seeing more than one.  He did however say that he never had an unobscured view due to the considerable disturbance the animal was making in the water (Nicholas Witchell, The Loch Ness Story, Penguin Books, 1975).  Now Gray estimated the animal to be 100 yards away, and his own height from the bluff on the shoreline to be 30 feet.  Some accounts quote Gray as giving the distance as 200 yards; but he also said it "rose out of the water not so very far from where I was"; based on his wording I feel more inclined to trust the 100 yard quotes.  Researchers visiting the site since then have also stated the elevation to actually be 40 feet, with F.W. Holiday even calling it 50.  I think 40 is the safer estimate for us to consider.  So going with 100 yards out and 40 feet above the waterline, this makes Gray's elevation relative to the animals a mere 8 degrees, with his view nearly broadsides; the photo supports both those conclusions.  Under these circumstances the silhouette of the nearer animal would almost completely mask or hide that of the second.  It would have indeed been difficult for Gray to tell it was two parallel animals.

We have the luxury of staring at an enlarged, static photo for as long as we like, whereas Hugh Gray only had a few minutes, and was dealing with his camera and probably looking through the view finder while snapping his five attempted photos.  Then there's all the thrashing and spray to obscure what he was watching.  Still, he says the "object of considerable dimensions" moved about a great deal for "a few minutes", and minutes are not seconds.  So if it's a pair, they must have stayed in close tandem for the minutes Gray watched them moving, for if they had separated by any distance he'd have noted it was two independent objects.  Unless we apply an even simpler explanation:  the second animal could have been on the surface at the start, been caught in the photo, but then submerged.  Then Gray, setting aside his camera, continued to watch the single remaining animal for the final minutes before it too submerged.

Let's look at the Heron-Allen image geometrically.  As stated above, Gray's line of sight was only 8 degrees above the water level.  In the diagram below I've placed two floating objects of equal size and shape next to each other, here viewed in cross-section.  Since we already have the angle, the actual height of the objects doesn't matter at this point, but Gray estimated the animal's height to be 3 feet above water, and so I have indicated the same.  The question is, would the camera be able to capture any noticeable separation of the two dorsal lines, and if so, how much?  We can see here that the back or top of the nearer object would appear one foot below the top of the further object.  The actual number of feet doesn't matter, as it's the ratio of the visible part of one animal to the visible part of the other animal we're trying to measure, and in this case the ratio is a clear 3:1.  That is, Gray's camera would capture an image, from the top down, consisting of 1/4 rear animal, and 3/4's front animal.  See the insert in the lower right corner of the diagram, where I've rotated the whole view slightly to make this more obvious:


This turns out to be extremely consistent with the amount of the further animal that is visible above the back  of the closer animal in the actual Gray Photo.  It's exactly what we'd expect in the photo, given the distance, the height of the observer, and assuming the two animals are of nearly equal size.  (Personally I think the nearest animal is the slightly larger of the two.  The distance between the apexes of the caudal fins is a bit larger than that between the front ends of the animals, which makes the rear one slightly shorter than the other.  But given that these are moving animals with sinusoidally flexing bodies, thrashing tails, and turning heads, it's impossible to be exact about which one may be longest.)

That there have been two animals present all along has an added benefit to us, as it answers not one but two of the unexplained problems previously related to the Gray Photo.  One of the first criticisms of the picture has always been that the body looked too "baloonish" or buoyant, and that a real animal wouldn't float that high in the water.  It only appeared this way because in the high contrast press images, two bodies had been lumped together vertically.  As soon as the second dorsal line is recognized and drawn in for the closest animal, and the viewer becomes aware of looking downwards at side-by-side animals, then Nessie's proportions get a lot sleeker.

Secondly, the parapodia Holiday recognized are no longer too low on the body to be accepted as appendages, because the height of the body above the waterline was never what it seemed.  The appendages are right where they belong, and always have been.


THE MORPHOLOGY REVEALED

Having taken the entire picture apart element by element earlier, it seems only fair to put it back together in the end. The overlay I drew for the Heron-Allen image makes for a good starting point:





One must guess at the features below the waterline.  I have ventured to assume the tail is vertically symmetrical, thus adding a ventral fin.  A laterally flexing, keeled tail makes for a powerful swimming appendage, which seems necessary to account for the great speed (as much as 10 knots) that's been reported for the animals.  Also, or perhaps I should say inevitably, that's the normal tail configuration for aquatic salamanders.




The exact size and shape of the appendages must remain conjectural.   I've gone with webbed feet here, but more flipper-like appendages are certainly possible; the posterior one could be a true flipper even if the front limb is more of a webbed foot.  Also the true girth is conjectural as well, with the body being perhaps a bit thicker than I've shown here.

Having recreated the front-most of the two animals, we now give a copy of that image an open mouth to yield an otherwise identical second animal, and lastly we place them together side by side with the further animal one head's length ahead of the other.  The final result is my recreation of the Gray Photo as we would see the animals if we could take away the water and fountains of spray:




As a bit of a reality check, I made one more rendition with the glare and water sprays manually airbrushed over the final reconstruction, to compare side by side with the original photo.  Not a perfect match, but sufficient I hope to demonstrate that, once the water is removed and precious few blanks filled in, we have two of the same animal present in the original Gray Photo:




Morphologically, the animal captured in the Hugh Gray Photo doesn't look very much like a fish in my opinion, but instead bears an exceedingly similar form to many aquatic salamanders.  But those of similar form and similar size are unknown outside the fossil record.  Within the fossil record though, they are quite well known.  When it comes to living forms, the Chinese Giant Salamander, Andrias davidianus, is recognized as the largest amphibian in the modern world, reaching a length of six feet.  The Loch Ness Giant Salamander seems to have that beaten by a factor of at least three, if not four or five.

This brings us to the taxonomy of the unidentified species in Loch Ness, and the related issue of how it came to populate the Loch in the first place.  I'll address both these items in a subsequent post article.

(If you are outside the posts thread, click here to view Part II of this article.) 

Wednesday, August 8, 2012

The Known Suspects - A Short Answer

While great discussions have been had over the possible candidates for the Loch Ness animal, and I may go into greater detail about some of those theories in later posts, we are going to get the ball rolling with a single, and I hope definitive, statement:

Nessie is not an air-breather, which consequentially rules out everything other than fish or amphibians.

Even if the temperature of Loch Ness was warm enough to support reptiles (which it is not) and even if Plesiosaurs were not thoroughly extinct (which, unfortunately, they are) you couldn't hide a population of them in Loch Ness -- you couldn't even hide one.  As air-breathers, Plesiosaurs would continuously and regularly surface.  Their respiration would rule their behavior, and we'd have had our type specimen in hand long ago.  There are other problems with any form of giant reptile in Loch Ness, but the respiration obstacle alone ends that debate. The theory that the unidentified creatures in Loch Ness represent a relic population of surviving Plesiosaurs has been the romantic favorite for so many decades that many people will be disappointed by this.  But alas, this is rather irrefutable logic.  Nessie never was nor ever could have been a Plesiosaur.

The same logic applies to mammals and birds.  Extinction and known range aside, Hydrodamalis gigas, or Steller's Sea Cow might be a suitable candidate based on size and anatomical appearance, and could tolerate cold water, but runs into the same initial problem as a Plesiosaur: it would constantly be coming up for air, and too hard to overlook.  The same is true of any less exotic aquatic mammals, of which only whales grow large enough to account for the size of our mysterious denizen.  Even granted some form of giant aquatic reptile or mammal came equipped with snorkeling appendages that permitted it to sneak breaths without fully revealing itself at the surface, that would still place it at or near the surface on a constant and regular basis.  Such an animal would still be spotted regularly by fisherman, or any sufficiently patient monster hunters.  It would also have to regularly show up on sonar scans in mid-water, never far from it's source of oxygen.  The infrequency of such sightings tells us: we are not dealing with an air-breathing animal here.

A nod must be paid to the late F.W. Holiday, who espoused for many years his theory that Nessie was a giant aquatic worm.  His book The Great Orm of Loch Ness outlines this theory, as well as delving deep into the dragon mythology of ancient Europe, and remains a great read to this day.  The obstacle to entertaining the possibility of a giant invertebrate again comes down to Nessie's behavior, but in this case the rarest and most mysterious quirk in that observed behavior:  land sightings.  No invertebrate of Nessie's size could voluntarily leave the water, enjoy a stroll, and return to the water.  Like a giant jelly fish it would collapse under it's own weight if removed from the water.  Even Holiday acknowledged this flaw in his otherwise rather good theory.  As infrequent as land sightings may be, they have been a constant part of the historical tradition, and an irregular but definite portion of modern, recorded sightings (perhaps as many as two dozen instances since the 19th century).

Ultimately, it all comes down to behavior.  Nessie is a bottom dwelling, water breathing animal that spends very little time on the surface or in mid-water, although just enough to be spotted visually or by sonar on very rare occasions.  Its forays up from the the depths are most likely made along the sides of the Loch, to feed on the fish which are predominantly found along the sides, in shallower water above the underwater cliffs that precipitously drop off into the 750 foot abyss.  Such behavior is only consistent with a fish, or aquatic amphibian, which can extract all of it's needed oxygen directly from the water.

Yet as seldom as it happens, and for reasons known only to the animal itself, Nessie also leaves the water for apparently brief stretches, as observed most famously in the Spicer and Grant sightings of 1933 and 1934 respectively.  It may be said that this is nothing new:  it's a centuries old tradition among the Highlanders that the kelpie or water horse of Loch Ness comes ashore.  That's a key behavioral trait to take into account if we are distinguishing fish from amphibians.

My next post will be a picture essay which will on the one hand "deconstruct" one of the more famous photographs ever taken at Loch Ness, while further demonstrating why we should be thinking in terms of the Loch Ness Giant Salamander.