Strade, a roughly one-year-old male falcon, was released by the charity Avian Rescue Otago following an eight-month recovery in captivity.
Avian Rescue Otago director and avian veterinary nurse specialist Alan Parker said it had been "touch and go" for the falcon in the early stages, as he had suffered significant head injuries following a collision with a glass balustrade two storeys above ground.
"He probably wouldn’t have made it more than a few more hours if he hadn’t had intervention," he said.
Strade had been delivered to a Wānaka vet by a member of the public, before being transferred to Avian Rescue Otago for urgent treatment.
Once stabilised, the bird of prey spent the better part of eight months recovering at Kārearea Falcon Trust in Marlborough.
Mr Parker said Strade’s recovery was "significant", as it had been against almost all odds.
"Most birds that come in with window strikes don’t survive."
"Hopefully he will be ready for breeding season, and will hopefully pair up and help the population a bit."
Strade had been tagged with a silver leg band, allowing conservationists and amateur bird-watchers to report sightings of him in future.
Mr Parker said he hoped Strade’s recovery would show people the importance of urgently seeking professional care when finding an injured bird.
"When it comes to the likes of these endangered species, if they come across them, it’s really important to get them into care in a timely manner."
The Department of Conservation website lists the New Zealand falcon as threatened.
The bird of prey is endemic to New Zealand. Between 5000 and 8000 are believed to exist in the wild.
