Denise Margot Callahan

A 52-year-old woman who has converted her back veranda into a koala hospital, bottle-feeding orphaned joeys at 2am and watching them through recovery or death. She's cared for 47 koalas over six years and buried 19. When she reads about an extinct Western Australian koala species, she doesn't see a fossil she sees her current joey's great-great-grandparents, a lineage that could end again.