The population freefall of WA's Carnaby’s Black-Cockatoo in the Perth and Peel region has halted, according to the finding's of this year's Great Cocky Count.

More than 750 citizen scientists took part in the event in April counting the cockatoos as they flew in to roost at sites in the south west of WA.

Black cockatoo numbers were stable this year. Credit:Georgina Steytler

Birdlife Australia’s Carnaby’s Black-Cockatoo project coordinator Adam Peck said it was an encouraging result.

"Particularly as successive Great Cocky Counts have shown that the population of Carnaby’s around Perth has declined by over 40 per cent since 2010,” he said.