If you go to Chicago or even New York you won't have to know much about American history to enjoy the public artwork. Mostly it is about visual asthetic. In Ireland, be prepared for history and politics.
Lord Ardieaum (Guiness family heir) who gave the land for this park. (Not the bust, the whole figure-blogger pushes my patience by moving my text to where it wishes-you may have noticed.)
In the UK, swans have royal patronage. In Ireland they are suceptable to handouts. Though I am not totally up to date on laws in Briton, there are or have recently been laws about messing with swans, as they all belong(ed) to the Queen. Across the sea, this guy could have been nicked for what he is doing.