 It has been suggested that the dodo may already have been rare or localised before the arrival of humans on Mauritius , since it would have been unlikely to become extinct so rapidly if it had occupied all the remote areas of the island . A 2005 expedition found subfossil remains of dodos and other animals killed by a flash flood . Such mass mortalities would have further jeopardised a species already in danger of becoming extinct . Yet the fact that the dodo survived hundreds of years of volcanic activity and climactic changes shows the bird was resilient within its ecosystem . 
