Contrafreeloading in umbrella cockatoos (Cacatua alba): Further evaluation of the play hypothesis.

Contrafreeloading is defined as choosing to perform work to obtain a reward, despite the presence of an identical, freely available alternative. According to standard learning and optimal foraging theories, it should not exist. Thus, any evidence of such behavior is noteworthy. We briefly review the recently introduced play hypothesis, which proposes that contrafreeloading is more likely if the action involved is viewed as play rather than work (i.e., agreeable rather than aversive). One might consequently expect species that are relatively more playful to be more likely to engage in contrafreeloading. We evaluated this possibility by testing purportedly playful umbrella cockatoos ); we studied four residents of a bird sanctuary in upstate New York (Dudley, JJ, Poly, and Teddy Bear). The task involved choosing between shelled and deshelled almonds; the former choice constituting evidence of contrafreeloading. We documented contrafreeloading in a novel species and then compared our results with previously published data on the reportedly less playful Grey parrots (). Individually, a higher percentage of cockatoos engaged in contrafreeloading on more than half the trials than did the Greys, with statistically similar levels of individual variation, but the overall amount of contrafreeloading was not statistically significantly different between the species at a group level. We discuss possible reasons for these findings. Additionally, we examine similarities in the behavioral expression of play and contrafreeloading. (PsycInfo Database Record (c) 2025 APA, all rights reserved).