"Powerful owls can be quite placid [even though] they are killing machines in some respects," Mr Bianchino said of the capture.

Vets found bruising under the wing and they recommended a stint for Bethany at the Higher Ground Raptor Centre, a non-profit group located near Fitzroy Falls in the Southern Highlands.

Hitting the right note

While the owlet recovered its poise and health over five days, the photographer visited the Lane Cove site regularly, playing a recording of the bird's trilling.

"One of [the parents] hooted back," he said. "It was a good sign."

His group, Save Beecroft Cheltenham Alliance, also organised for a professional tree climber to place the discarded bread tray about 20 metres up in the canopy when the bird was deemed ready for release.

Cardboard cage

And so last Wednesday as twilight arrived the owlet was hoisted in her unassuming cardbox into place.

Before long, mum was spotted, flying to a nearby tree. And soon after, dad arrived bearing dinner in the form a dead possum.

Visits on subsequent days would reveal dad only, and then mum and chick together on the same branch "literally touching", Mr Bianchino said, declaring the release a complete success.

There's one more challenge: the alliance is in talks with Ausgrid about possible reimbursement of costs that could total $4000.

Fairfax Media approached Ausgrid for comment.

"You've got to be wary [of what's there] before you go into these areas and start hacking into things," Mr Bianchino said.