Some clever magpies can recognize themselves in a mirror, leading researchers to include them among the ranks of self-aware animals—an elite group that is generally thought to include only humans, great apes, bottlenose dolphins, and elephants. This new study suggests that a brain capable of surprisingly sophisticated intelligence developed in a few birds long after they split from the mammalian evolutionary tree, about 300 million years ago. Says lead researcher Helmut Prior:
"It shows that the line leading to humans is not as special as many thought.... After finding this kind of intelligence in apes, many people thought it had developed once in one evolutionary line with humans at the end. The bird studies show it has developed at least twice"[Reuters].
The researchers tested the magpies' abilities by placing a bright yellow or red mark on the feathers just below their beaks, so the dots could only be seen by ...
