It is feared there may have been a mass poisoning of birds at a reserve on Auckland's North Shore.
Up to 100 pigeons, ducks, sparrows and pūkeko were found in varying stages of paralysis at Sherwood Reserve on Monday and Thursday evenings last week.
Auckland Council is working with the Ministry of Primary Industries and Department of Conservation to find out what happened.
North Shore resident Virginia Nichol, who has been rescuing birds for the past decade, took 67 of the sick birds into her home to treat them.
She told Checkpoint she believed they were poisoned.
"Several of the birds were upside down, feet in the air ... the birds are still very much alive, but just in a state of probably hypothermia, where they were just not responsive to what was going on around them," Nichol said.
"My view - it's not proven, there's been no confirmation of what's happened - is that it may have been a poison that was given to the birds," she said.
"They were all in a very small location, they were all in the same sort of state at the time, and just given some of the observations from people in the community, it just appeared to be something that had progressed quite quickly for the birds.
"The birds were in the kids' playground. I had a young child come up to me and go 'excuse me, there's a bird over in the corner there'. So this was impacting young families, this was impacting people in the shops that came out to find these birds like that. So it's very distressing for people, very confronting for people."
She found them when it was early evening, so a lot of the animal facilities were not open and she had to take the birds in as an interim measure.
"With some poisoning, you can find that the birds will turn around quite quickly within 24 to 48 hours and that's thankfully what had happened with these birds, most of them recovered within 24 hours, and all of them had really recovered with the two days ready for the release," Nichol said.
"There were 10 birds that didn't make it unfortunately, and they were pretty much close to death at the time of them being collected."
Samples were delivered to laboratories to do some testing to rule out is avian influenza obviously or other diseases that may be circulating.