Preface Carel ten Cate and Susan D. Healy; 1. Introduction: avian cognition - why and what? Carel ten Cate and Susan D. Healy; 2. Spatial cognition in birds James F. Reichert, Sebastian Schwarz and Debbie M. Kelly; 3. Spatial cognition and ecology: hummingbirds as a case study Susan D. Healy and T. Andrew Hurly; 4. Food storing and memory David F. Sherry; 5. Avian cognition and the evolution of warning signals Candy Rowe, John Skelhorn, Christina G. Halpin; 6. Social learning and innovation Louis Lefebvre and Lucy M. Aplin; 7. Solving foraging problems: top-down and bottom-up perspectives on the role of cognition Andrea S. Griffin and David Guez; 8. Objects and space in an avian brain Giorgio Vallortigara and Cinzia Chiandetti; 9. Physical cognition and tool use in birds Alice Auersperg, Irmgard Teschke and Sabine Tebbich; 10. Avian numerical cognition: a review and brief comparisons to non-avian species Irene M. Pepperberg; 11. Mechanisms of perceptual categorization in birds Ludwig Huber and Ulrike Aust; 12. Relational concept learning in birds Leyre Castro and Edward A. Wasserman; 13. The linguistic abilities of birds Carel ten Cate; 14. Avian vocal perception: bioacoustics and perceptual mechanisms Neil McMillan, Marc T. Avey, Laurie L. Bloomfield, Lauren M. Guillette, Allison H. Hahn, Marisa Hoeschele and Christopher B. Sturdy; 15. Sing me something: does song signal cognition? Neeltje J. Boogert; 16. Avian social relations, social cognition and cooperation Thomas Bugnyar and Jorg J. M. Massen.