Book excerpt: This book, while focusing on current preservation challenges posed by the Aga, or Mariana crow, also reflects the larger issues and challenges of biodiversity conservation in all oceanic island ecosystems. It evaluates causes for the continuing decline of the Aga, which exists on only the two southernmost islands in the Mariana archipelago, Guam and Rota, and reviews actions to halt or reverse the decrease. This book reminds us of the importance and challenge of preserving the unique environmental heritage of islands of the Mariana archipelago, the need for increased knowledge to restore and maintain native species and habitats, and the compelling and lasting value of extensive public education to stimulate environmentally informed public policy development.