Birds from Hopetoun and Munglinup will be examined today to see what caused their deaths.
The Department of Environment and Conservation has not ruled out poison as the cause of death of more than 190 birds on the South Coast.
The birds were discovered in Hopetoun and Munglinup last week after the region experienced extreme temperatures.
Most of the birds are believed to be the endangered Carnaby's Cockatoo.
Other species discovered include regent parrots, galahs, mudlarks, ravens, and yellow throated miners.
The heat is believed to have contributed to the deaths, however, the birds have been transported to Perth and will be examined today to confirm the cause