1. Chicks prefer to peck at insect-like elongated stimuli moving in a direction orthogonal to their longer axis

   • Elena Clara
   • Lucia Regolin
   • Lesley J. Rogers

   Original Paper 23 May 2009 Pages: 755 - 765

   

2. Memory for what, where, and when in the black-capped chickadee (Poecile atricapillus)

   • Miranda C. Feeney
   • William A. Roberts
   • David F. Sherry

   Original Paper 23 May 2009 Pages: 767 - 777

   

3. Visual and response-based navigation in the tortoise (Geochelone carbonaria)

   • Anna Wilkinson
   • Sacha Coward
   • Geoffrey Hall

   Original Paper 23 May 2009 Pages: 779 - 787

   

4. Comparing dogs and great apes in their ability to visually track object transpositions

   • Eveline F. Rooijakkers
   • Juliane Kaminski
   • Josep Call

   Original Paper Open access 27 May 2009 Pages: 789 - 796

   

5. Forest chimpanzees (Pan troglodytes verus) remember the location of numerous fruit trees

   • Emmanuelle Normand
   • Simone Dagui Ban
   • Christophe Boesch

   Original Paper Open access 31 May 2009 Pages: 797 - 807

   

6. The comparative psychophysics of complex shape perception

   • J. David Smith
   • Joshua S. Redford
   • Sarah M. Haas

   Original Paper 03 June 2009 Pages: 809 - 821

   

7. Influence of social conditions in song sharing in the adult canary

   • Katia Lehongre
   • Thierry Aubin
   • Catherine Del Negro

   Original Paper 04 June 2009 Pages: 823 - 832

   

8. Do dogs (Canis familiaris) show contagious yawning?

   • Aimee L. Harr
   • Valerie R. Gilbert
   • Kimberley A. Phillips

   Short Communication 19 May 2009 Pages: 833 - 837