Q – What did the grape say when an elephant stepped on him?
A – Nothing. He just let out a little wine.
The first alcohol I ever drank was home brewed. I was twelve when the evil liquor – orange and raison wine – was served up by my refreshingly enlightened policeman uncle of all people. We’d visit the house and find these wort-filled vessels in the bathroom, glug-glug-glugging as bubbles of carbon dioxide chugged through little glass airlocks.
Not that I was swilling the stuff in quantity you understand, but what better introduction to the practical application of biochemistry and chemical engineering. Who knows what influence these little episodes have on later life decisions?
Six years later, as an impoverished student at Birmingham University, I was brewing my own 40 pints of barely drinkable delicious Mild Ale (pronounced ‘m + oiled’ in the local dialect). And while I never got into the brewing habit big time, I still on occasion reach for the demijohn and yeast – like recently, prompted by the promise of summer blackberries and the pungent whiff of Thames-side hops.
It’s obvious booze is an educational resource we ignore at our peril; but to consolidate, consider what’s going on in that murky ochre, as it sits in my hall, infusing the carpets and curtains with its fruity ambience. I hope it’s this:
The contents of the bottle are yellow because the blackberries haven’t actually appeared yet, so for now I’m using Chardonnay grape concentrate out of a can. And as that contains fructose from the grapes plus added glucose syrup, and I’m adding sucrose on top of that, both reactions should have kicked off immediately – the whole thing enabled by one of my favourite eukaryotic micro-organisms – Saccharomyces cerevisiae: a wine yeast.
There’s nothing to do now until it ferments out, but I managed to kill 20 minutes using the chemistry and bubble rate data to figure out how things are ticking along. I reckon I’ll produce 511g of alcohol and 488g (273 litres) of CO2, which at the current bubble rate means the fermentation will take 6 days (workings in the end-notes for those interested and assuming I’ve remembered my O-level chem.).
We covered production of ethanol from fermentation at school, but I don’t remember doing any distillation (which is illegal without a license in the UK). Certainly nothing to compare with the alcohol education afforded 1960s American youth courtesy of the fabulous Golden Book of Chemistry Experiments (excerpts below), which covers fermentation with yeast plus the distillation/synthesis of ethanol, methanol, and a bunch of other fun compounds from the ethanol ‘Family Tree’:
I love the helpful precautionary note on chloroform:’THEN SNIFF CAREFULLY’. A complete home schooling if ever there was one:
That’s all really. I’ll update with a report on the finished product, assuming the wrong types of bug and oxygen don’t intervene and vinegarate the show.
One last item though. Yeast is of course also used in baking; the carbon dioxide from fermentation causes dough to rise. So here’s a particularly rigorous explanation of the process from Alton Browne. It’s over my head, but I’m sure the trained biochemists out there will relate. (Quality isn’t up to much either – sorry about that.)
Guessing there’s about 300g of glucose in the concentrate, and I know I’ve added 450g sucrose to 5.5 litres of water. As 1 Mole sucrose (242g) yields 2 Moles glucose/fructose (360g), 450g sucrose will make 669g glucose/fructose. With the 300g in the syrup that rounds up to about 1000g total C6H12O6. 1 Mole of C6H12O6 (180g) makes 2 Moles ethanol (92g) plus 2 Moles carbon dioxide (88), so 1000g should make 511g of alcohol and 488g carbon dioxide. That’s roughly half a kilo of alcohol in 5.5kg water, or, ignoring the density difference, about 10% by volume . These kits supposedly deliver 12%, so the 300g estimate was probably low. The volume of gas produced can be calculated given 1 Mole CO2 (44g) has a volume of 22.4 litres at STP (24.6 at current 25deg C room temp), so our 488g equates to 273 litres of gas having to bubble through the airlock. It’s bubbling at about 1 per second with an estimated bubble volume of half a cm3 ; so I figure at that rate it will take 6 days to ferment out. All of which seems to hang together with what it says on the tin.
On a winding stretch of the A5 road from North Wales to London – around Betys-y-coed and Llangollen – mountain scenery combined with the challenge of balancing speed, driver satisfaction, and passenger nausea makes the journey almost enjoyable. On the other hand, the interminably boring alternations of dual-carriageway and roundabouts that follow – between Oswestry and Shrewsbury – are a recipe for brain death.
Except, that is, one day last week, returning prematurely from a weather-killed ‘Welsh Break’, my mind buzzed over two critical questions the whole trip: What would our broken tent cost to fix? And why did the grooves on that boulder point to the North East?
Well spotted that woman at the back; this is a post where I obsess about a rock.
Boulder and SnowdonLocation in WalesLocation relative to Llanberis
The boulder in question sits about a half mile down the old Rhyd Ddu road outside Llanberis in Snowdonia. Its top surface is covered with North East-facing parallel grooves.
And that’s puzzling, because it looks like a moraine boulder dropped by a glacier, in an area where – having walked these valleys for years – I always assumed the ice had flowed towards the North West, away from Snowdon. Seeing as though the scrape marks left by glaciers – which is almost certainly what these are – align with the direction of glacial flow, something is amiss.
At this point, lest I raise galactic doubt and uncertainty beyond already dangerous levels, as Douglas Adams might say, rest assured this is all sorted – after a fashion but in a reasonably scientific way – by the end of the post. I also got a new tent pole: £15 – thanks for asking.
South Sea Wales
The relevant history starts around 400 million years ago with successive phases of volcanism, weathering, and glaciation (plus some folding and other geological processes). When the oceanic plate of Iapetus undercut the adjacent tectonic plate of Avalonian – all in the Southern Hemisphere back then – the resulting subduction generated enough heat for volcanoes to punch through Avalonia and form the upland region we now call Snowdonia1.
Source: WikicommonsSubduction Zone (Source:IAN Symbol Libraries)
The ensuing millenia saw wind, rain, and rivers transform the resulting mountain range from Himalayan grandeur to the more modest heights we see today; yet some of the most dramatic re-modelling was reserved for only the last 20,000 years or so. And it was caused by ice.
20,000 years ago we were at the peak of a major ice-age that buried the whole region under 1.4 km of ice, with just the tops of the highest mountains poking out. Moving under gravity, glaciers of rock-bearing ice flowed down the river valleys, gouging out the Llanberis, Nant Ffrancon, and other steep-walled passes, cutting through hard volcanic rock in a series of breaches, and scooping out rounded recesses, or cwms (known as corries in Scotland).
Llanberis Pass on the right, Cwm Brwynog to the leftView down Llanberis Pass from Llanberis
Chunks of rock, liberated by repeated melting and expansion of ice, or plucked out by other rocks, joined the glacier and travelled as an abrasive slurry beneath the ice – scoring anything in their path, before being released as ‘moraine’ when the glacier descended to a warmer altitude or the general climate warmed up sufficiently for the ice to melt.
Boulders falling on the surface of the glacier were likewise dumped, sometimes in incongruous isolation, their angular forms undamaged – like this one just off the Snowdon Ranger Path:
Moraine boulder east of Snowdon near Snowdon Ranger Path / Llyn Ffynnon-y-gwas
A Popular Destination
Did Darwin or Huxley pause at this one?
No shortage of historical figures are associated with glaciation and its geographical consequences, including: Louis Agassiz, Charles Lyell, Charles Darwin, Alfred Russel-Wallace, John Tyndall and Thomas Henry Huxley. Agassiz observed glaciers in Switzerland, and in 1840 was the first to suggest similar processes had operated in the upland areas of Britain (an assertion on which he was closely supported by William Buckland and Charles Lyell.)
Charles Darwin knew the region well2:
“I cannot imagine a more instructive and interesting lesson for any one who wishes (as I did) to learn the effects produced by the passage of glaciers, than to ascend a mountain like one of those south of the upper lake of Llanberis, constituted of the same kind of rock and similarly stratified, from top to bottom. The lower portions consist entirely of convex domes or bosses of naked rock generally smoothed, but with their steep faces often deeply scored in nearly horizontal lines, and with their summits occasionally crowned by perched boulders of foreign rock.”
The glacial boulders of North Wales, with their strange grooving, made a particular impression on Alfred Russel Wallace, the co-discover with Charles Darwin of evolution; commenting in his paper Ice Marks in North Wales3:
“..it frequently happens that grooves or scratches are made upon the rocks by the hard materials imbedded in the bottom or sides of the glacier. Owing to the enormous weight and slow motion of glaciers, they move with great steadiness, and thus the markings on rock-surfaces are almost straight lines parallel to each other, and show the direction in which the glacier moved.”
and:
“Nothing is more striking than to trace for the first time over miles of country these mysterious lines, ruled upon the hardest rocks, and always pointing in the same direction.”
Suddenly I feel less alone in my fascination.
In his hugely popular textbook on physical geography – Physiography4 – Thomas Huxley describes how glaciers flow over exposed bedrock to produce characteristic Roches Moutonnees formations (sheep-backs), complete with parallel striations:
But back now to the North West / North East question; a closer look at the Ordnance Survey and Google 3D map projections suggests an answer.
For directly to the South West of our boulder is a more local gouging of the hills in the form of Cwm Dwythwch and its attendant lake – Llyn Dwythwch, suggesting the area was subject to local glaciation running perpendicular to the main ice-flow from Snowdon. Indeed, the feature is discussed in a paper from the 1950s describing the glaciation as a distinct event, separated from the main ice-flows by 10,000 years in the last period of UK glaciation – the ‘Loch Lomond Advance’. The cwm certainly aligns with our boulder (pink X marks the spot):
Things are even clearer in glorious Google 3D, North at top:
or looking toward Snowdon:
In Late Glacial Cwm Glaciers in Wales5, Brian Seddon references Cwm Dwythwch and 32 other cwms or cirques in the region arguing they developed from snow and ice preferentially deposited on the sun-sheltered North and North Eastern faces of hillsides, assisted by snow-drifting induced by South Westerly prevailing winds (like we have today). Seddon recorded the moraine fields of 33 such cirques, plotting their altitude(circles) and aspect(radii) to illustrate the dominance of North/North East facing cwms. He placed the lowest extent of moraines in the Snowdon Group, containing Cwm Dwythwch, at 275 metres, which is above, but not far off, our boulder’s height at 240 metres. Maybe he didn’t count every individual boulder at the boundary? That Snowdonia was formed by a mix of ice-cap and localised glaciation is now widely accepted6,7.
Moraine altitude, aspect, direction in Seddon's Snowdon Group' After Seddon (Ref.5)
All of which, in conclusion, suggests our boulder most likely started life as a volcanic outcrop at the top of Cwm Dwthwch, was carried to its present position by a glacier in a secondary period of low temperatures and glaciation around 10,000 years ago, and picked up abrasions as it was overrun or carried in the North Easterly underflow.
All that with three qualifiers: (a) it’s not 100% certain the boulder is not actually an outcrop of bedrock (need to take a closer look next visit!); in which case it’s fair to assume it was simply overrun by the glacier; and (b) it’s possible the boulder was carried down from Snowdon in the first glacial episode and subsequently overrun by the secondary glacier (again, more research); or even (c) the boulder was scarred in the first episode and somehow got spun around 90 degrees just to fool us.
Clearly no rest for the rigorous – or obsessive weekend geographers – it would seem.
p.s. If any seasoned geologists out there want to put me right / out of my misery, please feel free :-).
Basecamp with pre-broken tent
References / Sources
1. Rock Trails, Snowdonia: A Hillwalker’s Guide to the Geology and Scenery. Gannon, Paul. Pesda Press, 2008
2. Notes on the Effects produced by the Ancient Glaciers of Caernarvonshire, and on the Boulders transported by Floating Ice, Charles Darwin, The Edinburgh New Philosophical Journal, 1842, p.362.
4. Physiography: An Introduction to the Study of Nature. T.H.Huxley, Macmillan, 1878, p.162.
5. Late Glacial Cwm Glaciers in Wales. Brian Seddon, Journal of Glaciology, 1957. In International Glaciological Journal, Volume 3, Issue 22 pp.94-96
6. The last glaciers (Loch Lomond Advance) in Snowdonia, North Wales. Gray JM 1982. Geological. Journal 17: 111-133.
7. Allometric development of glacial cirque form: Geological, relief and regional effects on the cirques of Wales, Ian S. Evans, Geomorphology Issues 3-4, 1986
8. The Early History of Glacial Theory in British Geology. Bert Hansen, Journal of Glaciology, Vol 9, No.55, 1970.
Galileo Galilei’s scrape with the Roman Catholic Church is well known.
His suggestion that the Earth spins on its axis and orbits around the Sun was an afront to scripture that got him branded as a heretic and almost burnt at the stake. How he first became aware of the full peril of his situation is less well known: on a rooftop in Rome, eavesdropping whilst taking a pee behind a bush.
Maybe that’s how it happened, maybe not – either way, the Earth won’t stop turning.
But it’s through these touches of imaginative license: sometimes humorous, sometimes tragic, on occasion disturbingly vivid, that Stuart Clark breathes life into the characters of his first novel, The Sky’s Dark Labyrinth.
The title comes from an episode in the book, where Galileo explains the hopelessness of trying to understand the universe without the correct language – mathematics; to do so is to “wander about lost in the dark labyrinth of the sky.” But don’t panic, it’s an equationless drama.
In this first part of a trilogy that reaches from the sixteenth to the twentieth century, we follow the lives of the astronomers Tycho Brahe (1546-1601), Johannes Kepler (1571-1630) and Galileo Galilei (1564-1642) as they challenge the religiously inspired orthodoxy of the times: an Earth-centered universe with the Sun and planets orbiting around in perfect circles – just as God intended.
Each astronomer has special skills and his own ideas about the cosmos:
Tycho, the meticulous naked-eye observer, happy for the Sun to orbit the Earth, yet convinced the other planets revolve around the Sun.
Galileo, arguably the father of evidence-based thinking, points his telescope skyward to see mountains on the moon, satellites around Jupiter, moon-like phases on Venus and Mercury, and spots on the Sun (Clark reminds us Galileo didn’t actually invent the telescope) – each observation a blow to the accepted model of the universe and Aristotle’s concept of a perfect heaven.
And Kepler, obsessed with geometry, turns a rigorous mathematical eye to his compatriots’ data to derive a model of eliptical planetary motion that, relativistic effects aside, is valid to this day.
On the journey, we share starry rooftop nights with Tycho and his armillary spheres and sextants; and with Galileo and his telescope. We encounter scientific concepts, painlessly embedded in the story, from stellar parallax to Kepler’s defining relationship for a planet’s distance and period round the Sun.
We meet the landmark publications that captured these ideas: Kepler’s discussion of perfect polygons Mysterium cosmographicum, his treatise on Mars: the Astronomia nova, and the Rudolphine Tables of star positions; Galileo’s telescope observations in Sidereus Nuncius and his more troublesome endorsement of Copernican ideas in Dialogue Concerning the Two Chief World Systems.
The whole is delivered through a pacey narrative that switches back and forth through time and space. One moment we’re in Rome, then Prague, then Florence, then Rome again. Thus Clark weaves his factually-based interplay of lives and ideas.
As in any drama, characters are developed in contexts that resonate with our personal experience: relationships, families, squabbles, births, marriages and deaths – as far as that’s possible 400 years on. Is that illusory? Can we ever really see from behind 16th century eyes? No, we can’t. But how else to share Kepler’s wonder as he steps out onto the observatory roof, or taste Tycho’s not-so-scientific bon vivre lifestyle and lordly pride, or feel Galileo’s chill dread as he anticipates what a rabid Inquisition has in store?
And that, in a nutshell, is Clark’s proposition.
It’s one where he’s shown due respect for the underlying history, reflected perhaps in a favouring of credible human vignettes over elaborate manufactured sub-plots. So, lots of expansion on the meetings, schemes, and conflicts that must have taken place but would never be recorded – scenes that can be directed and embellished to divert and entertain without compromising the main account.
In this regard, it’s a very different book to, say, Edward Rutherfurd’s London, where the main story lines are totally fictional. Clark’s work comes over as based on historical record and scientific fact. It’s important, as historians of science in particular can, understandably, take issue with inaccurate or controversial portrayals; I’m thinking of a recent defence of Nevil Maskelyne, the 18th century Astronomer Royal, demonised in the film version of Dava Sobel’s Longitude.
The Sky’s Dark Labyrinth begins in Rome, where a defiant Giordano Bruno, comfortable only with his conscience, waits in a cell to be burnt at the stake for heresy.
Johannes Kepler, an outcast Lutheran, arrives in Bohemian Prague to join the service of Tycho Brahe, and get a first sniff of the observational data he’ll one day build into a planetary model. He also hears about one Galileo Galilei of Padua, and the wonderful discoveries he’s made with his telescope (before long Kepler will have one of his own).
And all the time the Roman Catholic Church is watching, keeping tabs on these dangerous individuals, their troubling independence and inconvenient appeal to evidence. Kepler is spyed on – his mail intercepted. Galileo, at first encouraged by the Pope, is told in no uncertain terms to leave theological interpretation to the Church; but his thoughts are already committed to print. Thus the slippery slide to persecution, recantation, and repression is joined.
The plot moves between the bloody war-torn streets of Prague and the red robed intrigue of Vatican corridors. Current events in Reformation Europe are dominated by the struggle between an increasingly Jesuit-influenced Catholic Church and a rising tide of Lutherism. And our astronomers are in the thick of it.
Far from being godless atheists, they aim to explain God’s works – not undo them. Yet a Catholic Galileo and a Lutheran Kepler still each grapple to rationalise their ideas to themselves and to a world of dogmatic orthodoxy. A world where political, theological, and philosophical considerations hold sway over rationalism; where solidarity of belief and allegiance to the group is prized over individual will, conscience, or even physical proof; where mathematical descriptions are acceptable as professional tricks, but will never define truth; where witchcraft is a burning issue, and astronomy is inseparably tied up with the superstition of astrology.
Indeed, Kepler makes a good living drawing up horoscopes for wealthy patrons and courtly sponsors – a trade he revisits as the need arises (Clark actually credit’s him with a rather modern pragmatism on these issues).
Reformation Europe is also a great background for some of Clark’s more vivid visualisations, reminiscent of a Terry Gilliam movie in their medievalism. I love the “gobs of some thick unguent” Kepler spies clinging at the margins of Tycho’s prosthetic nose when they first meet, and the mood-setting ‘unpleasant tang of tallow’ in Kepler’s study.
Life is dirty, smelly, and not a little dangerous.
On the downside, I occasionally lose track in the switching interplay of events and locations, feeling the need to draw little timeline diagrams – lest I get totally lost in the labyrinth. And oblivious to any description or other literary signposting, I only ever thought of our heros as bearded old men. I’ll call it William Shakespeare syndrome- there just aren’t enough ‘before they were famous’ portraits out there.
But none of that detracted from The Sky’s Dark Labyrinth as a thoroughly entertaining and recommended read.
In capturing that essential excitement of the night sky, unchanged over the centuries, Clark has created a work accessible to all comers, and one that astronomers and history fans in particular will doubtless lap up.
I look forward to meeting Isaac Newton, Albert Einstein and Edwin Hubble in future installments.
Like re-animated sea creatures from the Darwin Wing of the Natural History Museum, these animals look strangely alive, bubbling in their specimen bottles.
Steffen Dam’s glass sculptures are inspired by nature. (Photo: Tim Jones. Items displayed by Joanna Bird Pottery at Collect 2011, Saatchi Gallery, London)
In fact, this is the work of Danish glass sculptor Steffen Dam, one of the more nature-inspired craftsmen who grabbed my attention yesterday at Collect 2011– the Crafts Council-organised exhibition hosted by London’s Saatchi Gallery.
I say inspired, as Dam doesn’t claim his works are perfect scientific reproductions. But they’re technically and aesthetically fascinating all the same, and piqued my interest for a closer look.
Steffen Dam was represented at the exhibition by Joanna Bird.
Last week’s Public Attitudes to Science report from Ipsos MORI and BIS says a lot about how the public feel about and engage with science.
The Summary is worth five minutes of anyone’s time.
But what came unbidden to my mind, as I pondered how informed or uninformed people are about science, was a visit from a neighbour last week, and a reminder that we don’t need to appear on the telly or be called Brian Cox to do our own bit for science communication.
Basically, the guy spots me over the fence messing around with my telescopes, and invites himself over for a look-see. And, yes, he has been ‘Wonderised’ by Brian.
So I drop plans to photograph the ISS – I’ve got enough of those anyhow – and instead show him Saturn through the little ETX-90. For a first view through a telescope we could hardly do better.
We talk about the earth’s rotation and why the telescope’s axis points at the pole – watching Saturn scoot across the view with the drive turned off. We talk about the cost of kit, magnification, aperture, and what can be achieved with a pair of binoculars.
The forgotten ISS appears. Ultra-bright. Fantastic stuff.
The truth is that astronomy could have been designed for engagement, with other areas of science and engineering not lending themselves to a hands-on demo in quite the same way. I’ve worked with everything from fluid mechanics, to ultrasonics, to high-power lasers and the thermodynamics of steelmaking slags. It’s all fascinating stuff (believe me :-P); and while earthbound, still somehow less accessible than the stars.
This is where good science writing steps in; but TO MY POINT: if you know something cool – don’t wait for an invite to the Royal Society or the BBC to share it. And have a peep over your neighbours fence; you might see something interesting. (But don’t get arrested either.)
I’ve just started playing with Dipity timelines, and as it’s Thomas ‘Darwin’s Bulldog’ Huxley’s birthday today, 4th May, here’s a work-in-progress showing some of the events in his life.
Three views from a pass of the International Space Station last night.
(a) From the West rising under Cancer, through Serpens on the way to Leo. (M44 Beehive cluster is just visible in Cancer if you click to enlarge)(b) Continuing under Leo(c) Into Virgo (heading towards Saturn on this occasion).
Taken in sequence, 22.20 GMT, 27 April 2011. Exposure 20 seconds at f.4, ISO500, 17mm on Canon 7D.
The trail is starting to dim in the last picture, and disappeared completely over the next five seconds.
To find out when the ISS is next coming over, I get Twitter alerts from Twisst.
With a diameter of 120,000 kilometres and a bright reflective surface, Saturn is an unmissable object in the night sky right now. But at 1.3 billion kilometres away from us, it looks only a hundreth the size of the full moon. Which means the screen width of my Saturn video below represents one third of a lunar diameter across (for best view, click to full screen):
[jwplayer mediaid=”9786″]
I recorded the movie through my old but capable 1978-vintage 6″ Fullerscopes reflector – specially resurrected for Easter after 30 years in storage. (See my efforts with the moon and the smaller ETX-90 telescope in Armchair Astronomy.)
Fullerscopes 6″ at left, after the clean-up, ETX-90 at right
Getting the telescope up and running really required nothing more than (literally) brushing away some cobwebs and giving the mirrors a wash – something I’d be more hesitant of doing had I not just read a step-by-step ‘how to’ in Sky at Night magazine.
Dirty mirrorDiagonal
Although thick with dust and grime, I’d reason to believe the mirrors’ coatings beneath were o.k., as I remember having them vacuum re-aluminised and silica coated just before I abandoned the instrument and disappeared off to university. Some gentle soaking, swabbing, and rinsing down with distilled water, and all was shiny once again.
CobwebsBefore
Fullerscopes’ german equatorial mountings were all built like tanks – this ‘Mark II’, rated to carry a 10″ reflector, is still in good order save for some rust on the exposed steel shafts.
The RA drive, that ordinarily would drive the telescope counter-rotational to the Earth’s axis, wasn’t operational for a variety of reasons; but the fine adjustment on the declination axis was working.
Fullerscopes Mk II Equatorial Mount
All of which goes to explain why on the clip Saturn appears to fly across the screen.
Soaking
I’d forgotten how stunning to the eye Saturn is through this telescope. In better seeing conditions I’ve seen the gap in the rings – the Cassini Division – quite clearly. Now, Saturn’s moon Titan was unmistakable.
Filming what you see with your eye is a little more challenging, although the ‘live view’ on the Canon 7D makes life a lot easier. Rather than watch the live feed through a computer, on this occasion I used the camera’s LCD display directly to focus with the help of a magnifying glass. The clip was made by projecting the image onto the camera’s CCD sensor via a 12.5mm orthoscopic eyepiece; the main mirror’s focal length is about 1250mm. The scene could have stood higher magnification, but I was limited by the eyepiece focal length and size of the projection tube.
Good as new
All in all, considering the state of the equipment at the start of the day, I’m happy with the end result. The gap between the disk of Saturn and the rings is clear enough; but no Cassini division – so still some work to do! All the same, a fun day messing around with telescopes and engineering – no better way to spend the Easter hols.
2. To be exact: the angular size of Saturn on 25/4/2011 was 19 seconds (“) of arc, approximately a third of a minute. There are 60 seconds in a minute, and the moon is typically 30 minutes across; so Saturn appears one ninetieth of the moons diameter.
Eurasian Green Woodpecker, Picus viridis, female. (Photo: Tim Jones)
Through a combination of photography and a creeping fascination with avian behaviour and taxonomy (thanks to my wife giving me Colin Tudge’s The Secret Life of Birds for my birthday) I think I’m turning into some sort of accidental ornithologist. Point being, you can expect the occasional photo-flavoured birdy post; and today – it’s woodpeckers!
The female Eurasian Green Woodpecker (Picus viridis) above is one of the three most common woodpeckers found in the UK.
Photographically, woodpeckers are a challenge. The whole family is jumpy, taking off as a matter of principle at the sniff of a threat. So, considering I was sneaking up with no hide, I’m pleased how these turned out. Here are a few more of the male/female pair and a juvenile. You can tell the male by the red flash under his eye (click thumbnail to open slideshow):
And this male Great Spotted Woodpecker (Dendrocopos major)was snapped only a few days ago (click thumbnail to open slideshow):
Globally, there are 218 species4 in the Picidae family to which woodpeckers belong, living in every country with trees except for Australia and New Zealand.
Here are two more I snapped in California. The first set shows an Acorn Woodpecker Melanenpes formicivorus and the Ladder-backed Woodpecker Picoides scalaris (click thumbnail to open slideshow):
Here’s a video of a female Ladder-back hunting for bugs:
Acorn Woodpeckers are expert at turning trees into communal larders or caches. Pecking thousands of small pits in a single tree, they’ll place an acorn in each one – ready for harder times.
This set, again taken in California, is of a female Williamson’s Sapsucker – a member of the family specialising in eating the sap out of small wells drilled into the bark of pine trees:
Woodpeckers are a wonderful showcase for evolutionary adaptation.
Bird foot types (WikiCommons)
Sharp claws set on toes laid out in the zygodactylous pattern – two toes facing forward, two back – are ideal for tree climbing. (Parrots and cuckoos are set up similarly, and elsewhere in the animal kingdom – Chameleons.)
Then there’s the way they hold themselves on the tree trunk.
Like rock climbers and photographers favour three points of contact for security and stability, woodpeckers have evolved a stiff tail to brace against the tree trunk and make a sturdy triangle with their splayed legs. The Sapsucker below demonstrates nicely; you can see her two tail quills bending under the pressure.
Williamson’s Sapsucker – three points of contact
Having formed this miniaturised drilling platform, woodpeckers set-to doing their thing, which for a Ladder-backed woodpecker is banging its beak into bark and wood at up to 28 times a second, repeating the act several hundred times a day1.
Williamson’s Sapsucker, Sphyrapicus thyroideus, Los Angeles area, USA (Photo:Tim Jones)Great Spotted Woodpecker pecking for termites
The aim is to locate and consume insects and sap from under tree bark, a task for which their long, barbed tongue is well suited. But as this Great Spotted demonstrates, the birds are not above pecking the ground if there are bugs and termites to be had.
As hole-dwellers, woodpeckers also peck to hollow out a nest – a process that can take up to a month and involve the removal of tens of thousands of wood chips4.
For me, the woodpeckers’ most impressive adaptation is the multi-element shock absorber system that’s developed in and around its skull to prevent brain damage from all that bashing.
Shock absorption in woodpecker skull (Picture credit:IOP and Digital Morphology.)
The full complexity of the system has only recently come to light. X-rays of a woodpecker’s head showed that the massive deceleration occuring at beak strike is cushioned and spread out thanks to elasticity in the beak, a spongy area of bone at the front of the skull, and a further special structure – the Hyoid – that directs pressure from the rear of the birds tongue around the back of its head1.
Well that’s a wrap on woodpeckers for the moment. Next phase is to try and catch these guys on HD video; they’re doing some great little courting dances this time of year. Reaches for camouflage gear….
References and further reading
1) A mechanical analysis of woodpecker drumming and its application to shock-absorbing systems. Sang-Hee Yoon and Sungmin Park 2011 Bioinspir. Biomim.6 016003 IOP Publishing doi: 10.1088/1748-3182/6/1/016003
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