Update to the OP survey:
I have 3 videos of a my 20 year old hand-raised Goffin (Gabby) unthreading a nut from 2.5 inches of bolt. That's a lot of revolutions, and Gabby discovered the most effective method is using his tongue to continuously rotate the nut. The back-story is he and his brothers are the proverbial destructive Houdinis and have either destroyed or learned to bypass every lock on their cages. The nuts/bolts have been retired, and when necessary the cages can be secured with a length of stainless-steel wire. I am in the process of replacing the cages with a *hopefully* more secure locking system!
I have another interesting video of him attempting to problem-solve access to muffins inside a clamshell-type container. The lower half is black plastic contrasting with a clear upper enclosure. Gabby understands lifting along the demarcation of halves is key, yet he lacks the beak-strength to accomplish the task. The video shows him tackling several sides of the container as well as looking at the muffins from the top and testing the material with his beak.
The videos reside on my iPhone and I'm not particularly savvy with media transfer. I can forward them to you from the phone either by email or message. AFAIK as a new member you don't yet have PM privileges on the forum, but I believe one of our moderators can act as intermediary with the relevant communications! Let me know if this will help your research!!
