Date of Award

Spring 5-15-2020

Document Type


Degree Name

Master of Arts (MA)



First Advisor

Dr. Irene Pepperberg

Second Advisor

Dr. Diana Reiss

Academic Program Adviser

Dr. Diana Reiss


This study examined contrafreeloading—choosing a physical task to access food over free food—in two Grey parrots (Psittacus erithacus). Both birds contrafreeloaded for food of equal or higher value, but differed in which contrafreeloading task they preferred. Differences between the parrots are considered as individual preferences for self-reinforcing tasks.



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