"Insightful" string-pulling in Grey parrots (Psittacus erithacus) is affected by vocal competence
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Updated: Aug 2, 2026

Targeted Training of Ultrasonic Vocalizations in Aged and Parkinsonian Rats
Published on: August 8, 2011
1MIT School of Architecture and Planning, Bldg 7-231, 77 Massachusetts Ave, MA 02139, Cambridge, USA. impepper@media.mit.edu.
Abstract:
Four Grey parrots (Psittacus erithacus) were tested on their ability to obtain an item suspended from a string such that mutiple, repeated, coordinated beak-foot actions were required for success (e.g., Heinrich 1995). Those birds with little training in referential English requests (e.g. "I want X") succeeded, whereas birds who could request the suspended item failed to obtain the object but engaged in repeated requesting.
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