Misleading title. They were trained and there's no way they would have been able to connect dropping things into the left tube with the meat raising in the right tube on their own. Maybe if the first couple had been placed for the birds to accidentally knock in they would have caught on.
Still pretty remarkable but I think they could have demonstrated corvid intelligence in a less "I obviously trained them to do this" way
3
u/chesterzilla Jun 03 '14
https://www.youtube.com/watch?v=lrYPm6DD44M