Is
this what a luminous or glowing owl would look like?
Sceptics notwithstanding, the phenomenon of
luminous birds whose lengthy history I surveyed recently on ShukerNature in
Part 1 of this two-part review (click here to read Part 1) is assuredly genuine, but how
can it be explained? Five principal potential solutions have been suggested by
amateur naturalists and professional scientists alike down through the ages,
and these are as follows:
1) It is due to the
bird having made physical external contact with phosphorescent organisms living
on decayed wood in tree holes
The idea behind this suggested solution –
the most familiar and extensively documented of the five under consideration
here – is that such contact would cause phosphorescent bacteria, plants, and
fungi growing on the wood to become attached to the bird's feathers, thereby yielding
an area of luminescence upon its plumage.
How
a glowing barn owl with a particularly luminous breast might look
However, whereas the parts of a bird's
body most likely to make contact with wood when entering or exiting a tree hole
would be its wings and head (brushing against the rim of the hole), the body
region actually exhibiting most (or all) of its perceived luminescence in those
specimens that have been reported has tended to be the breast, with the wings and
head sometimes giving off little (if any) light.
Also, it must be remembered that glowing
examples of extremely large birds, such as North America's great blue heron Ardea herodias, standing 45-54 inches
tall, have been recorded – and it seems highly unlikely that birds of this
stature would (or could) inhabit tree holes.
A
great blue heron (© Mike Baird/Wikipedia – CC BY 2.0 licence)
In addition, and as its common name
suggests, the barn owl, the most popular identity for luminous owls, prefers to
roost in barns or deserted out-houses rather than in tree holes (though it will
roost in them if need be).
Yet if this option is nonetheless a viable
one in relation to certain bird species, a common phosphorescent fungus likely
to be involved is the honey fungus Armillaria
mellea – a very abundant, widespread, edible species (or species complex,
as is nowadays deemed to be the case) that lives on trees and woody shrubs, and
sports bioluminescent mycelia yielding an ethereal greenish-blue glow commonly
referred to as foxfire.
The
honey fungus Armillaria mellea (©
Stu's Images/Wikipedia – CC BY-SA 3.0 licence)
Indeed, I remember reading long ago a
fascinating snippet of information demonstrating just how powerful the foxfire glow
of this fungal species can be. Edited by Dilys Breese, and published by the BBC
in 1981, the multi-contributor book Wildlife
Questions and Answers included the snippet in question, provided by
correspondent R. Watling, and which reads as follows:
I have often seen the eerie
light of the honey fungus in a tropical rain forest. You see all the leaves and
stems and trunks, twenty-five feet tall maybe in an old tree, with this
beautiful glow, just like a silver lady among the trees. And these fungi can
even take their own photographs! If you set up a camera next to one of them, given
enough exposure time, you will get a picture of the fungus all bright and
shiny, taken by its own luminescence.
Schistostega luminous moss inside a Japanese cave (© Dr TerraKhan/Wikipedia –
CC BY-SA 3.0 licence)
Another species likely to play a part in
this particular proffered solution is a phosphorescent plant officially called
the luminous moss Schistostega pennata,
but also known by such charming colloquial names as goblin gold and rabbit's
candle. As noted by bryologist Sean Edwards in a letter published by BBC Wildlife Magazine in April 1994, its
luminous portions are the first cells produced by germinating spores, which act
like thousands of pear-shaped microscopic cat's eyes, collecting and
concentrating even the faintest light. It is often found growing inside (and
illuminating) rabbit holes, hence its 'rabbit candle' moniker, yielding a
greenish-gold glow.
2) It is due to the
bird having ingested phosphorescent microbes
As the luminescence of birds is external,
and has actually disappeared in some cases following moulting, one would assume
this to be a phenomenon associated exclusively with the bird's external covering,
i.e. its plumage, rather than due to any digestive or other metabolic process
(but see also Solution #4 for some ostensible exceptions to this statement).
Of course, we could speculate that if any
phosphorescent microbes were inadvertently ingested with food, they could pass
out of the bird's body within its faeces, which might then in some way become
smeared upon its plumage, perhaps during preening, rendering it phosphorescent
in turn.
Also, it should be borne in mind that not
all phosphorescent bioluminescent fungi are harmless. One such species that is
poisonous is Omphalotus olearius, the
so-called jack-o'-lantern mushroom. This orange-gilled European fungus grows
around the bases, stumps, and buried roots of hardwood trees (a related
species, O. illudens, occurs in North
America). A bird perching upon it may conceivably find itself with fragments of
this fungus attached to its plumage, especially upon its breast feathers,
rendering them phosphorescent, but if the bird then attempts to remove such
fragments by preening, it could inadvertently swallow some of them and thereby
become ill from the toxic nature of this fungus.
Jack-o'-lantern
mushrooms (public domain)
Perhaps this is why some luminous birds
that have been physically examined have been found to be in poor health, such
as Rolfe's barn owl, and the specimen documented later here that was captured
by a Norfolk engineer in his back garden.
Nevertheless, although such a scenario is
not impossible, it is certainly not very plausible as an all-embracing
solution.
3) It is due to the
growth of feather-specific phosphorescent microbes upon the bird's breast
plumage
In some ways paralleling the previous two
proffered solutions, this third one proposes that phosphorescent bacteria or
fungi may grow upon a bird's breast feathers if they have become damp or dirty.
Propounded by British zoologist William P. Pycraft (1868-1942) among others
during and beyond the Norfolk luminous owl 'flap', it derives support from the
fact that breast feathers are often particularly dense (as with those of
pigeons, for instance), thereby encouraging microbial proliferation upon them.
Also, the breast is a difficult region for many birds, especially short-billed
ones, to reach satisfactorily when preening. How
an owl with plumage infested with green-glowing phosphorescent fungi may look
Furthermore, in his article, de Sibour
noted that avian luminescence is particularly powerful during flight. He sought
to explain this occurrence as an effect of superoxygenation, pointing out that
if a medium containing phosphorescent particles is agitated, that medium's
luminescence does increase.
Consequently, this third suggested solution
to the enigma of luminous birds would seem to be the most tenable of the three
considered by me here so far. Even so, in view of the comparative rarity of
glowing birds while concomitantly bearing in mind that a very great many birds
must at some time or another possess damp and/or dirty breast feathers, this
solution still falls some way short of providing a wholly satisfactory
explanation.
4) It is due to
some internal light-generating metabolic process
There are certain especially mystifying
cases in the luminous bird files that if accurate seem to indicate that those
individual birds' luminosity was directly linked not to any externally-sited
phenomenon but instead to their own internal metabolism. For in each case, its
external luminosity vanished once the bird itself had died. The earlier-mentioned
gamekeeper Fred Rolfe who in 1897 had shot down a luminous sphere in Norfolk
and found it to have been a barn owl in very poor condition made no mention of
any such occurrence, but it was a notable feature of the two incidents now
documented by me here.
The
July 1911 issue of The Irish Naturalist
contained several reports and reviews by different writers appertaining to
luminous birds, especially luminous owls, but the report of especial interest
here concerned a luminous specimen of North America's afore-mentioned great
blue heron, as I'll be documenting below shortly.
How a luminous specimen of a great white heron, the white
colour phase of the great blue heron, might look
In
his own Irish Naturalist survey of
reports, C.B. Moffat referred to a very interesting rural belief apparently prevalent
in both Europe and North America that I hadn't previously encountered but which
is very pertinent to the luminous great blue heron specimen. Here is what
Moffat revealed:
A belief has long
prevailed ascribing similar luminosity [to that of owls] to several of the
herons and bitterns, which are supposed to be assisted in their nocturnal
fishing operations by a phosphorescent light emitted from the "powder-down
patches" of the breast-feathers, a light that is thought to serve,
perhaps, the double purpose of attracting fish to the vicinity and helping the
watchful bird to see them.
Powder-down
feathers are specialized down feathers that grow continuously, in specific
tracts, but are only produced by four taxonomically-unrelated bird groups (parrots,
herons, bustards, and tinamous). In some such species, the tips of these
feathers' barbules disintegrate, yielding fine powdery grains resembling dust
or talc but composed of keratin; in others, the powder grains originate from
cells surrounding the barbules of growing powder-down feathers. When a bird
spreads these grains over its body during preening, they assist in protecting, ridding
of parasites, and waterproofing the bird's plumage and skin, but well worth noting
here is that they also confer upon its feathers a noticeable sheen.
James E. Harting
(public domain)
Moffat
then stated that wildlife observer James E. Harting had presented a resume of
the principal evidence relating to this belief within a chapter entitled 'The
Fascination of Light' contained in his book Recreations
of a Naturalist (1906). In particular, Harting had referred to a detailed
account by Philadelphia-based hunter W.J. Worrall of how he had shot a luminous
specimen of the great blue heron. According to Worrall, the heron had possessed three phosphorescent spots – "one in
front, and one on each side of the hips between the hips and the tail". The
description went on to state that as the fatally-wounded bird expired, so too
did its luminescence, its lustre "disappearing entirely with death".
Of interest, the location of
this heron's three phosphorescent spots matches the location of some of the paired,
dense patches of powder-down feathers in herons, which occur on their breast,
flanks, and rump. So, might those phosphorescent spots simply have been
extra-powdery (thence unusually pale and shiny) patches of powder-down
feathers? Worth noting here is that in a Forest
& Stream article written by American naturalist Charles S. Westcott and
published in 1874, Westcott stated that he had experimented in a dark room with
the powder from the powder-down feathers of least bitterns Botaurus exillis, the New World's smallest species of heron,
"and found it to be of the same nature as 'fox-fire'". Moreover, J.P.
Giraud, Jr., author of The Birds of Long
Island (1844), affirmed that the powder-down of dead herons "gives out
a pale glow, not unlike that produced by decayed timber, familiarly termed
'light wood,' or 'fox fire'".
A least bittern (public domain)
How, then, can we not only reconcile
the above evidence provided independently by Westcott and Giraud that powder-down
luminescence is not linked to a bird's life or death with Worrall's
contradictory claim that the luminescence of the glowing heron that he had shot
faded away once the bird itself died, but also (assuming its veracity) explain
his latter claim?
The fundamental biological problem
that Worrall's claim poses was highlighted by none other than Charles Fort – America's
premier collector and chronicler of newspaper cuttings reporting anomalies
across the entire spectrum of "damned" (i.e. scientifically-rejected
or ignored) phenomena – when reporting in his book Lo! (1931) a second case in which this same luminescence-themed
incongruity featured.
Charles Fort (public domain)
Fort referred to a report
published on 7 February 1908 in Norwich's Eastern
Daily Press newspaper (Norwich being a major city in Norfolk), in which engineer
Edward S. Cannell of Lower Hellesdon, Norwich, claimed that on the early morning
of 5 February when still dark he had seen something shining on a grass bank in
his back garden, and that when it fluttered down a path there he discovered
that it was a "bright and luminous" owl. He was able to capture the
owl, which seemed to him to be ailing, and took it indoors, where it soon died.
According to Cannell: "It was still luminous, but perhaps the glow was not
as strong as when I saw it first" – i.e. its luminescence began fading
following the owl's death. Moreover, in a sequel report, published by the same
newspaper on 8 February, it was revealed that Cannell had taken the dead bird
to a Mr Roberts, of Norwich-based taxidermists Roberts & Son, who claimed
in an interview: "I have seen nothing luminous about it".
Needless to say, if both
Cannell and Roberts were telling the truth, i.e. regarding the former's claim
concerning the owl's brighter luminocity when alive than when newly dead and
the latter's claim that when he later examined its corpse there was no
luminosity at all, this is a most unexpected turn of events. For as Fort
astutely pointed out:
Of course a
phosphorescence of a bird, whether from decayed wood, or feather fungi, would
be independent of life or death of the bird.
Indeed it would.
Consequently, the only plausible explanation for any cases like Worrall's heron
and Cannell's owl that feature synchronicity between a luminous bird's death
and the disappearance of its luminescence would seem to be that the latter
characteristic was caused by some intrinsic physiological, bioluminescent
process – whereby the living bird was actively generating its luminescence via
a specialised metabolic process, which obviously would therefore cease once the
bird died.
Might a glowing owl's luminescence in reality be
bioluminescence?
Yet although bioluminescence
is well-documented from a wide range of organisms, it is currently unknown from
any birds. (What has been confirmed,
meanwhile, is that many bird species possess plumage that glows in the
ultraviolet section of the electromagnetic radiation spectrum; but as human
eyes cannot detect ultraviolet light, this particular type of plumage glow
remains invisible to us.) Nor has this physiological condition been confirmed from any other tetrapod vertebrate (but click here for my investigation of a highly-controversial Trinidad lizard claimed by some researchers to be bioluminescent).
Of significance,
furthermore, as revealed in his earlier-cited American Midland Naturalist article from 1947, is that during his
researches into glowing birds, McAtee requested fellow American scientist Edwin
R. Kalmbach to send him some specimens of the powder-down tracts from American
black-crowned night herons Nycticorax
nycticorax, a nocturnal species often claimed by eyewitnesses to be
luminescent. He duly tested these tract specimens for the presence of luciferin
and luciferase, the compounds inducing bioluminescence in known bioluminescent
species, but he found no traces of them.
Black-crowned night heron (© ramidos/Wikipedia – CC BY-SA 4.9 licence)
Consequently, even if
certain bird species are indeed somehow bioluminescent, they nonetheless must
also be externally luminescent if like herons they possess powder-downs,
judging not only from McAtee's failure to link these feathers to
metabolically-induced bioluminescence, but also to the above-reported findings
of Westcott and Giraud that samples of these feathers' powder derived from dead
birds continue to be luminescent. To my mind, however, this seems a superfluous
and therefore impractical, implausible duplication of glowing ability.
5) It is due not
to birds at all but features non-living BOLs instead
Investigators of the unexplained will be
well aware that all manner of anomalous non-living phenomena involving
mysterious glowing balls of light (frequently abbreviated to BOLs or BoLs) have
been reported from many parts of the world, and include spooklights, foo fighters,
ball lightning, and min-min lights, as well as more familiar, scientifically-resolved
examples like the will-o'-the-wisp or ignis fatuus (resulting from the
oxidation of phosphine, diphosphane, and methane, compounds produced via
organic decay in marshes, bogs, and swamps). So might reports of luminous birds
in reality involve BOL phenomena and not feature birds at all? Whereas it is
certainly possible that some may have done, examples of such entities being
shot down and found to be birds obviously cannot be explained away like this.
Moreover, whereas it is true that the Haddiscoe sightings took place in
marshes, where will-o'-the-wisp activity would not be surprising, others have
occurred far from such terrain.
Coloured
wood engraving of a will-o'-the-wisp in a marsh, by Charles H Whymper (©
wellcomeimages.org/Wikipedia – CC BY 4.0 licence)
Equally problematic for a BOL explanation
regarding luminous birds are those examples in which the luminous entities have
been observed moving in an evidently conscious, self-aware manner. Relevant
here is that in an exact reversal of the above-mentioned suggestion that
luminous birds may be BOLs, many investigators of Australia's most famous
unexplained BOL phenomenon, the mysterious min-min lights long encountered in
Queensland, nowadays deem it more likely that these glowing enigmas are not of
any meteorological or chemical-based origin but are actually living creatures,
specifically barn owls, precisely because of the ostensible curiosity and
inquisitiveness that min-mins demonstrate towards their human observers. Here
is a prime example, as documented by me in my book The Unexplained (1996):In the days of Australia's early European settlers, the Min-Min Hotel was a staging post between Boulia and Winton in western Queensland, whose best-known feature for the people living nearby were the ghostly balls of light that regularly flitted through the air, often white but sometimes changing colour. Still seen today and referred to as min-min lights, these are reminiscent of American spooklights and English will-o'-the-wisps, and display a marked if disconcerting tendency to follow and even taunt their perplexed observers. For example: You Kids Count Your Shadows, a collection of Wiradjuri aboriginal lore and beliefs from New South Wales compiled by Frank Povah [and published in 1990], contains an account of a sheep drover who was checking his flock on horseback one evening when a blue min-min light appeared over his shoulder, and persistently followed him during his work. In exasperation, he chased after it, still on horseback, but was unable to catch up with it – until he gave up, and began riding home, whereupon the min-min cheekily appeared over his shoulder again! Man vs Min-Min – envisaging a rider in Australia's outback being trailed one evening by a min-min light (image created by me using Grok)An alternative 'living entity' explanation for such sightings may be luminous insect swarms, which have also been suggested as explanations for certain UFO reports (click here for my ShukerNature article documenting this possibility), but a curious, inquisitive barn owl, especially if encountered while out hunting at night, could surely explain at least some min-min reports. Reading back through my analysis of the five suggested solutions presented here, I think it most likely that as with so many other mysterious phenomena, luminous birds may not involve just a single solution but instead features a combination of different ones, with some cases resolved by one solution, certain others by a second, and so on. For it is abundantly clear that none of the solutions individually provides a comprehensive explanation for all of the cases documented here.
It is sad that such a captivating
phenomenon as luminous birds has fallen out of scientific favour in modern
times, especially as science is now equipped with so much readily-available
sophisticated technology with which to investigate it thoroughly. Of course,
this is due in no small way to the equally sad scarcity of reports nowadays.
Saddest of all, however, as noted by David Clarke in his Fortean Studies article chronicling the luminous owls 'flap'
reported in Norfolk during the early 1900s (referenced by me in Part 1 of this
review), is that this scarcity may well be due in turn to how much rarer, as a
result of habitat destruction and poisoning by pesticides, the barn owl has
become in Britain and elsewhere during the century or more that has passed since
the Norfolk 'flap'. Then again, if the numbers of this species, now extensively
protected, do eventually re-attain their former level, perhaps this most
delightful and whimsical of wildlife anomalies may once again attract the
attention of professional and amateur enthusiasts and eyewitnesses all over
again, back in fashion at long last.
Close
encounter of the glowing kind!
Finally: worth noting here is that
phosphorescent bacteria were declared the official answer to the anomaly of a leg
of lamb that glowed in the dark and which had recently been purchased in the Worcestershire
town of Kidderminster, England, during spring 1988. As reported by the Sandwell Express & Star newspaper on
12 March 1988, when the discovery was first announced there were fears of
Chernobyl-derived radioactive fall-out from its nuclear power station's
explosion two years earlier. However, Hereford-Worcester's county analyst and
scientific advisor Geoffrey Keen rightly rejected this melodramatic notion in
favour of phosphorescent bacteria being responsible, thereby solving with
Sherlockian skills of deduction the curious case of the luminous leg of lamb.
If you haven't already done so, be sure
to check out Part 1 of my luminous birds review article here on ShukerNature.
NB – All images of luminous owls included
here were created by me using Grok X1.
More
close encounters of the glowing kind!