I've found a transcription of the recording in the booklet of the cd Traditional Songs of Ireland (Saydisc), that is based on Folktrax recordings. It seems correct, but in a couple of cases, I stick to what I've written down before: the booklet has "cheerful song", but I still think Margaret sings "mournful song"; the booklet has "as Jack he's waited long", it could be, but I'm not sure; the booklet has "instead three mounted police", I've kept "out stepped".

There was a wild colonial boy, Jack Duggan was his name
He was born and reared in Ireland in a place called Castlemaine
He was his father's only son, his mother's pride and joy
And dearly did his parents love the wild colonial boy

At the youthful age of eighteen years he began his wild carreer
With a heart that knew no danger, with a heart that knew no fear
He robbed the rich to help the poor and stabbed James MacEvoy
An' a terror to Australia was this wild colonial boy

One day he on the prairie as Jack he rode along
He was listenin' to the mocking bird singing a mournful song
Out stepped three mounted police: Kelly, Davis and Fitzroy
And they all set out to capture him, the wild colonial boy

He fired a shot at Kelly, which brought him to the ground
And turning to fist Davis, he received that fatal wound
A bullet pierced his proud young heart, from the pistol of Fitzroy
And that is how they captured him, the wild colonial boy