I am really fascinated by crows and their ilk. This year we have seen entire flocks of crows that were around double their usual size, making them more like the size of ravens.
I remember recently reading a study of crows' use of tools,
In the experiment, the crow was given a stick and food behind a cage wall. The crow used the stick to drag the food within reach.
In another more complex experiment, the crow ended up using a sequence of three tools to get the food, rather ingeniously, I felt.
When I was a teen, I used to breed rats (domestic hooded rats) and thought that they were the most intelligent mammal for their size, but I now have to give the crown to the humble crow.
Interesting how they do seem significantly smarter than many other breeds of bird.