The WA Museum is currently studying the distribution and movements of both species of white-tailed cockatoos (Baudin's Cockatoo and Carnaby's Cockatoo) and the Forest Red-tailed Black Cockatoo. All three species occur in Roleystone.
Information on identifying these species is given in Bush Topics - Black Cockatoos http://www.roleybushcare.com/bush-topics/92-forest-red-tailed-black-cockatoo.html.
A lot more detailed information on the Baudin's Cockatoo is given in the paper by RE Johnstone and T Kirby entitled 'Distribution, status, social organisation, movements and conservation of Baudin's Cockatoo (Calyptorhynchus baudinii) in South-west Western Australia' in Records of the West Australian Museum 25: 107-118 (2008). This report describes how hundreds of Baudin's Cockatoos roost overnight in trees on Lady McNess drive near Araluen during the winter months and fan out during the day in family groups.
The more observations that people send in to the museum recording the numbers of cockatoos, the direction they are flying or what the cockatoos are feeding on the better the picture that can be drawn about where the cockatoos go during the day and what their habitat requirements are.
Instructions for sending in records are given at the end of the Black Cockatoos Bush Topics.
I have kept a record of Cockatoo sightings starting in 1991 until 2009. The following file contains information based on observations on my property in Rodgers Court, Roleystone. (This is off Simons Drive)
whitecockatoos_lee.pdf