WA Museum curator of ornithology Dr Ron Johnstone is warning that the iconic black cockatoo could be extinct within 50 years.
He is calling for a cull of corellas in Mandurah and for councils to plant more cockatoo-friendly plants and trees.
“European honeybees and corellas take the cockatoos’ hollows,” he said.
“The corellas need to be culled to keep the hollows available.”
Dr Johnstone said the region was an important breeding area for the cockatoos.
“There are sites used at Lake Clifton, Baldivis, Stake Hill and Lake McLarty for breeding,” he said.
“There are other pockets of forest red-tail hanging on despite urban development, but it doesn’t take a lot to tip the balance.”
The bird was once prolific in the Peel region, but locals say bird numbers have been steadily declining.
Peel Preservation Group secretary Shirley Joiner said the region would lose one of its most iconic birds if they became extinct.
She said there are not enough trees and due to the time it takes for them to grow, simply replacing them is inadequate.
“Every time a building is approved, they knock down a few trees – it has a cumulative effect,” she said.
Lightning struck a tree used for nesting and food on Manjoogoordup Road last Friday and the tree was removed.
This tree was one of many on the road with cockatoo tubes installed for nesting.
If land at Point Grey is developed, land at Gingin will be provided as an alternate cockatoo habitat, but Ms Joiner said this was not appropriate as male cockatoos will not venture far from the nest to forage for food.