THE Department of Environment and Conservation is investigating the death of seven corellas at a Greenwood park late last week.
Local residents suspect poison may have killed the birds found at Blackall Park, early on Thursday morning.
City of Joondalup staff removed the birds, which the DEC is examining.
The cause of the bird deaths may not be known for several days.
A surviving bird, which local resident Pam Cockroft took to Balcatta Veterinary Hospital, was put down after its condition deteriorated.
Ms Cockroft, who was at the park to walk her dog, said the sight of so many dead corellas was upsetting.
“I wrapped one that was still alive in a towel and took it to the vet hospital and then went back to the park and took some photos,” she said.
“I am really concerned these birds could have been poisoned by pecking at the ground.
“The birds were mainly in one area of the park.
“I feel someone has done this, otherwise the (dead) birds would have been around the streets (as well).
“There is some lovely wildlife in this area, including magpies.”