FarmI wrote:

And how could I possibly know that? It's a feral, and like all ferals it
takes off like a rocket at the first sight of a human heaving into view.
That is why it's still alive and not dead and buried. I love birds but the
Currawongs do more damage to the bird population that it seems this cat has
done.

You will not know how much damage the cat has done until it disappears
and the years roll bye. OTOH, currawongs do have a natural impact.