The population of a black cockatoo species native to WA's South West is in freefall, according to a stocktake that found it could be all but extinct within 20 years.
Birdlife Australia yesterday released the results of its annual great cocky count and claimed there had been a 15 per cent drop in sightings of Carnaby's black cockatoos in the past year.
According to the conservation group, the decline was consistent with the previous four years and suggested the population of the species could halve again in five years.
Longer term, it said, prospects for the bird were grim as encroaching urban development and a drying climate pushed the species out of its habitat.
"By 2029 . . . the population will have collapsed to the brink of extinction," Birdlife spokeswoman Jessica Lee said. "The cockatoo is already recognised as being at high risk of extinction."
Community group Friends of Underwood Avenue, which is fighting to preserve bushland in Floreat used as a "roosting" site by the birds, said the results of the count were unequivocal.
"Unless there are major changes to protect and increase the habitat of Carnaby's cockatoos, these iconic birds of Perth will be extinct within our lifetime," spokeswoman Margaret Owen said.