Parrots join apes and Aristotle in the club of reason

African grey parrots are capable of logical reasoning

source: New Scientist vol 210 no 2818, June 25 2011 p16

African grey parrots are capable of logical reasoning to calculate where they might find food. Sandra Mikolasch and team from the Konrad Lorenz Research Station, Vienna University, Austria, studied seven African greys. They liked both walnuts and seeds. The researchers hid a walnut under one cup, and seeds under another, while the parrots were watching. They then hid the cups and removed a treat, and showed the treat to the parrots. One parrot achieved a 75% success rate in guessing which treat must remain, and where it was, inferring through excluding. The other parrots fared better when they could always see the treats.
BI,BT