Machine derived contents note: Foreword -- 1. The diversity of penguins -- 2. Genus Aptenodytes -- 3. Genus Pygoscelis -- 4. Genus Eudyptes -- 5. Genus Megadyptes -- 6. Genus Eudyptula -- 7. Genus Spheniscus -- 8. Threats, conservation, watching penguins, and the future -- Glossary -- References