Chough project (online)

from the exhibition guide:

The chough appears black on the blog, and will appear white in the cathedral. Through this device, the chough as a symbol of Cornwall, also comes to symbolise good/evil and life/death.

Black is the colour of mourning: white is worn at weddings and christenings.

A black/white dichotomy appears in literature and in the Bible: most obviously in the story of Noah, when Noah sends out both a raven and dove.

It also occurs in Tristan and Isolde, a myth set in Cornwall, where white and black boat-sails are used as symbols of life and death.

from sacred-texts.com

THE CORNISH CHOUGH.
THE tradition relative to King Arthur and his transformation into a raven, is fixed very decidedly on the Cornish Chough, from the colour of its beak and talons. The --
"Talons and beak all red with blood"
are said to mark the violent end to which this celebrated chieftain came.

courtesy of the CBWPS website:

Three Choughs arrived on the Lizard peninsula in south-west Cornwall early in 2001. Two of the birds paired up, the third leaving the area. The pair nested successfully in 2002, the first breeding in England for fifty years.
They have bred annually since, raising a total of 20 young. In 2006 a second pair bred. They are made up of a male from the 2004 Lizard brood and an unringed female. Three young fledged, making a total of eight young this year. A third pair built a nest but the female was found dead.
In north-west Europe, Choughs still breed in Scotland, Ireland, Wales, the Isle of Man and Brittany. In 1992 there were 342 pairs in Britain and the Isle of Man. Elsewhere in Europe, the birds breed in mountains from Iberia, through the Alps to Greece and Turkey.

from the exhibition guide:

...projecting a white chough onto the roof of the cathedral suggests that the building is haunted by a ghost or spirit. At some level the image and the building become one.

courtesy of www.bryccancarey.com:

THE CORNISH CHOUGH
by John Harris

WHERE not a sound is heard
But the white waves, O bird,
And slippery rocks fling back the vanquish'd sea,
Thou soarest in thy pride,
Not heeding storm or tide;
In Freedom's temple nothing is more free.

'T is pleasant by this stone,
Sea-wash'd and weed-o'ergrown,
With Solitude and Silence at my side,
To list the solemn roar
Of ocean on the shore,
And up the beetling cliff to see thee glide.

Though harsh thy earnest cry.
On crag, or shooting high
Above the tumult of this dusty sphere,
Thou tellest of the steep
Where Peace and Quiet sleep,
And noisy man but rarely visits here.

For this I love thee, bird.
And feel my pulses stirr'd
To see thee grandly on the high air ride,
Or float along the land,
Or drop upon the sand,
Or perch within the gully's frowning side.

Thou bringest the sweet thought
Of some straw-cover'd cot,
On the lone moor beside the bubbling well,
Where cluster wife and child,
And bees hum o'er the wild:
In this seclusion it were joy to dwell.

Will such a quiet bower
Be ever more my dower
In this rough region of perpetual strife?
I like a bird from home
Forward and backward roam;
But there is rest beneath the Tree of Life.

In this dark world of din,
Of selfishness and sin,
Help me, dear Saviour, on Thy love to rest;
That, having cross'd life's sea,
My shatter'd bark may be
Moor'd safely in the haven of the blest.

The Muse at this sweet hour
Hies with me to my bower
Among the heather of my native hill;
The rude rock-hedges here
And mossy turf, how dear!
What gushing song! how fresh the moors and still!

No spot of earth like thee,
So full of heaven to me,
O hill of rock, piled to the passing cloud!
Good spirits in their flight
Upon thy crags alight,
And leave a glory where they brightly bow'd.

I well remember now,
In boy-days on thy brow,
When first my lyre among thy larks I found,
Stealing from mother's side
Out on the common wide,
Strange Druid footfalls seem'd to echo round.

Dark Cornish chough, for thee
My shred of minstrelsy
I carol at this meditative hour,
Linking thee with my reed,
Grey moor and grassy mead,
Dear carn and cottage, heathy bank and bower.