Wildlife officers have urged motorists to avoid endangered Carnaby's black cockatoos which are in the Perth area after their breeding season in the Wheatbelt.
Department of Parks and Wildlife senior wildlife officer Rick Dawson said many Carnaby's had returned from the Wheatbelt with their fledglings and were moving along the Swan Coastal Plain in search of food and water.
There was usually an increase in the number of black cockatoo deaths from vehicle strikes during February and March, and there had already been 34 needing treatment at Perth Zoo after being injured in the metropolitan area, he said.
"We know that many more are hit by vehicles and never reported to the department," Mr Dawson said.
"As a large-winged bird, black cockatoos usually take off into the wind, often putting them in the path of vehicles, so we ask that motorists slow down safely when they see a black cockatoo and approach with caution."
Mr Dawson asked people to report injured cockatoos to the department and also advise of any deaths because their DNA could aid further research into the species.
He's warned people to use a towel when picking up injured cockatoos to avoid being bitten.
The birds should be put in a dark box and taken to a wildlife rehabilitation centre or to a local vet who will arrange for it to be collected.
According to the federal Department of the Environment, Carnaby's populations have declined by more than 50 per cent in the past 45 years, and they are no longer breeding a third of their former breeding sites in the Wheatbelt.
The cockatoos are specially protected fauna in WA.