The State-wide cockatoo census, The Great Cocky Count, will take place next month in an effort to monitor the numbers of the endangered Carnaby's black cockatoo.
Environment Minister Bill Marmion said volunteers were needed to help stake out the black cockatoo's night roost sites from Geraldton to Esperance and the interior to the Wheatbelt on April 7.
Last year, 350 volunteers visited 229 places in search of night roosting sites and in the greater Perth region 6,600 black cockatoos were counted.
Mr Marmion said last year the focus had been on the metropolitan area but this year they were seeking information about bird numbers anywhere the species roosted at night, expanding the census to rural WA.
"The Great Cocky Count was so successful in 2010 that this year we want to expand the survey to include roosting birds from Geraldton all the way to Esperance," he said.
"The strong community support, especially from members of Birds Australia, makes it possible to cover a vast area and visit all roost sites on the same evening, giving a 'snapshot' count of bird numbers.
"It will also help determine whether the population has declined or increased since previous surveys in 2006 and 2010."
Mr Marmion said the Department of Environment and Conservation and Birds Australia are trying to map the critical habitat of Carnaby's black cockatoo in the hope of preventing further decline in the species.
Anyone interested in being involved in the Great Cocky Count should visit greatcockycount@birdsaustralia.com.au