1. Does captivity alter problem-solving behavior in Goffin’s cockatoos?

   • Irene M. Pepperberg

   Outlook 24 February 2021 Pages: 1 - 2

2. The conscious crow

   • Onur Güntürkün

   Outlook Open access 17 February 2021 Pages: 3 - 4

3. Anybody watching? How others affect helpful actions

   • Manon K. Schweinfurth

   Outlook 03 September 2020 Pages: 5 - 6

4. A special issue in honor of Irene Pepperberg: The chemist of comparative cognition

   • Debbie M. Kelly
   • Lauren M. Guillette

   Editorial 11 February 2021 Pages: 7 - 8

5. Convergent evolution of complex cognition: Insights from the field of avian cognition into the study of self-awareness

   • Luigi Baciadonna
   • Francesca M. Cornero
   • Nicola S. Clayton

   OriginalPaper 13 July 2020 Pages: 9 - 22

   

6. Conspecific presence, but not pilferage, influences pinyon jays’ (Gymnorhinus cyanocephalus) caching behavior

   • Alizée Vernouillet
   • Hera J. M. Casidsid
   • Debbie M. Kelly

   OriginalPaper 02 December 2020 Pages: 23 - 35

   

7. Kea, Nestor notabilis, achieve cooperation in dyads, triads, and tetrads when dominants show restraint

   • R. Schwing
   • E. Meaux
   • R. Noë

   OriginalPaper Open access 02 February 2021 Pages: 36 - 53

   

8. Response of male and female domestic chicks to change in the number (quantity) of imprinting objects

   • Bastien S. Lemaire
   • Rosa Rugani
   • Giorgio Vallortigara

   OriginalPaper Open access 06 October 2020 Pages: 54 - 66

   

9. Estimating on the fly: The approximate number system in rufous hummingbirds (Selasphorus rufus)

   • Mia Corliss
   • Theo Brown
   • Maria C. Tello-Ramos

   OriginalPaper Open access 14 December 2020 Pages: 67 - 75

   

10. Same/different concept learning by primates and birds

    • Anthony A. Wright
    • Debbie M. Kelly
    • Jeffrey S. Katz

    OriginalPaper 09 March 2021 Pages: 76 - 84

    

11. Towards describing scenes by animals: Pigeons’ ordinal discrimination of objects varying in depth

    • Suzanne L. Gray
    • Muhammad A. J. Qadri
    • Robert G. Cook

    OriginalPaper 23 September 2020 Pages: 85 - 98

    

12. The paradoxical performance by different species on the ephemeral reward task

    • Thomas R. Zentall

    OriginalPaper 24 June 2020 Pages: 99 - 105

    

13. Innovative problem solving in macaws

    • Laurie O’Neill
    • Rahman Rasyidi
    • Auguste M. P. von Bayern

    OriginalPaper Open access 07 December 2020 Pages: 106 - 123

    

14. String-pulling in the Goffin’s cockatoo (Cacatua goffiniana)

    • Birgit Wakonig
    • Alice M. I. Auersperg
    • Mark O’Hara

    OriginalPaper Open access 22 January 2021 Pages: 124 - 136

    

15. Social factors in bird-song development: Learning to sing with friends and rivals

    • Michael D. Beecher
    • Çağlar Akçay

    OriginalPaper 20 August 2020 Pages: 137 - 149

    

16. Constraints on vocal production learning in budgerigars (Melopsittacus undulates)

    • Michael S. Osmanski
    • Yoshimasa Seki
    • Robert J. Dooling

    OriginalPaper Open access 02 March 2021 Pages: 150 - 158

    

17. Who is crying wolf? Seasonal effect on antipredator response to age-specific alarm calls in common ravens, Corvus corax

    • Mario Gallego-Abenza
    • Christian R. Blum
    • Thomas Bugnyar

    OriginalPaper Open access 08 January 2021 Pages: 159 - 167