In a logic test, Eurasian jays quickly learned that adding stones to a cylinder half-filled with water would bring a tasty treat floating on the surface within reach of their beaks. In a second task the jays realised it was better to use pebbles, which sink, than corks, which float.
Great spotted woodpecker. About blackbird-sized and striking black-and-white. It has a very distinctive bouncing flight and spends most of its time clinging to tree trunks and branches, often trying to hide on the side away from the observer. Its presence is often announced by its loud call or by its distinctive spring 'drumming' display. The male has a distinctive red patch on the back of the head and young birds have a red crown.
Guinea fowl - not the brightest of our feathered friends but characterful and very attractive. Just don't try raising large flocks of them; they will take to the nearest roof at dusk and make noises akin to multiple car alarms all going off at once.