Doc has urged the public to keep an eye out after five sick or injured ruru came into its care during May, including one found in Greymouth in mid-May.
Doc Greymouth operations manager Chris Hickford said the injured ruru was found on a roadside and unable to fly.
It was handed in by a member of the public.
Senior technical adviser Cassie Mealey, who rehabilitates native birds in her spare time, initially cared for the injured owl.
A few days later "Usha", as they named it, was flown to the South Island Wildlife Hospital, courtesy of Air NZ and into the care of wildlife vet Pauline Howard.
X-rays showed the bird had a fractured coracoid — a deep chest bone that helps stabilise flight muscles — probably the result of being hit by a vehicle.
"Usha was a model patient, and she had an uncomplicated recovery," Ms Howard said.
On recovery the bird had "rehab flight training" before being returned from Christchurch to Greymouth for release.
It was one of five ruru in Ms Mealey’s care through May.
Most had fractures from suspected vehicle strikes; or suspected secondary poisoning after eating baited rodents.
Mr Hickford said Ms Mealey’s work and that of the South Island Wildlife Hospital was much appreciated.
"Doc can’t look after every bird, so we rely on a network of individuals and organisations nationwide who donate their time to do this work," he said.
Ms Mealey said ruru were being commonly spotted in people’s backyards now.
"It is likely that the cooler weather and mice boom at this time of year that has driven them into urban areas where there is more food such as moths around streetlights and mice around houses and compost bins.
"They commonly fly into the sides of buildings or are hit by cars.
"People can help protect ruru by maintaining old trees, as they like to nest in tree cavities instead of on the ground, where they are more vulnerable.
"You can also build nest boxes and place them in trees." — APL
