Are four treats better than two? Not if you're a crow picking a favorite snack. Crows and ravens hold off on gobbling a tidbit when they can see a better one coming after a short wait.
One question in an animal cognition is whether animals other than humans have the ability to recognise themselves. A classic way of testing this, established in 1970 by Gordon Gallup, is the `mirror test'.
This rare crow can select a tool and manipulate it to pry tasty treats from crevices in under a minute.This video was reproduced with permission and was first published on September 14, 2016. It is a Nature Video production.