The precise text given in the published work of Sigerson Clifford differs from the usual lyrics. Unsurprisingly they have mutated over the years. But some of the Clifford original touches are very interesting. Amongst many other changes, the place names which are in their anglicised form in the original have become Irish and the original name of one of the 'boys', 'Dawly', has become 'Daly'. Most interestingly Clifford referred to the bird as 'wran' rather than 'wren'. Whilst the change from 'wran' to 'wren' is entirely understandable, some of the other changes aren't. I'm about to learn the song and am going to try the original Clifford words.
The published text reads:

THE BOYS OF BARR NA SRAIDE

O the town it climbs the mountain and looks upon the sea,
At sleeping time or waking time, 'tis there I long to be,
To walk again that kindly street, the place I grew a man,
And the Boys of Barr na Sraide went hunting for the wran.

With cudgels stout we roamed about to hunt the droileen
We looked for birds in every furze from Letter to Dooneen:
We danced for joy beneath the sky, life held no print or plan
And we Boys in Barr na Sraide, hunting for the wran.

And when the hills were bleeding and the rifles were aflame,
To 'the rebel homes of Kerry the Saxon stranger came,
But the men who dared the Auxies and fought the Black and Tan
Were the Boys of Barr na Sraide hunting for the wran.

And here's a toast to them tonight, the lads who laughed with me,
By the groves of Carhan river or the slope of Beenatee
John Dawly and Batt Andy, and the Sheehans Con and Dan,
And the Boys of Barr na Sraide who hunted for the wran.

And now they toil in foreign soil, where they have gone their way
Deep in the heart of London or over in Broadway,
And I am left to sing their deeds, and praise them while I can
Those Boys of Barr na Sraide who hunted for the wran.

When the wheel of life runs down and peace come over me,
O lay me down in that old town between the hills and sea,
I'll take my sleep in those green fields the place my life began,
Where the Boys of Barr na Sraide went hunting for the wran.

Source: Sigerson Clifford. Ballads of a Bogman. p84-85. Mercier Press, Cork: 1986.
ISBN 1 85635010 X