The 'Save the Cassowary' campaign aims to protect the remaining cassowary populations in Daintree and Mission Beach by securing their rainforest habitat from residential development. Led by the Rainforest Information Centre and supported by various groups, the campaign seeks immediate government funding and actions to preserve the habitat, including a $30 million buyback for at-risk properties. Advocacy efforts include public pressure through online submissions, media outreach, and meetings with politicians to promote the campaign's goals.