Sculptor Marty Beckwith said he studied images of the bird diving and he then had a picture in mind for his artwork.
Beckwith’s work is the latest sculpture to be placed on the Peter Nicholls Memorial Plinth in the church’s public garden area.
A new sculpture appears there about every six months and the diving falcon is the fourth artwork since the initiative began.
Organising committee co-ordinator Stuart Griffiths said public sculpture had become more rare in recent times.
The works in the series in the Knox gardens were self-funded by the sculptors, he said.
A ceremony acknowledging the latest sculpture was held on Friday.
The Department of Conservation has said kārearea are capable of flying at speeds of up to 200kmh.
Beckwith’s version is less dynamic, but it does move.
The bird can be spun into different positions.
Beckwith, of Waikouaiti, said the rusted look - from corten or weathering steel - was a first for him.
Surface rust was a protective layer preventing further rust, he said.
