Poultry with brains
Some of them use tools, others can recognize themselves in a mirror - birds are capable of amazing mental feats. How do they manage that with their tiny brains?
Gerti was next on the experiment plan. After my collaborators and I removed the magpie (Pica pica) from its cage and covered its head with a cloth in my laboratory at the Ruhr University Bochum, we attached a small yellow paper sticker to its black feathers at the throat. Then we put her in another cage with a big mirror. We left Gerti alone and went into a neighboring room to watch her on a monitor. Gerti looked in the mirror and immediately tried to get rid of the sticker by scratching her neck or rubbing the floor. After successfully eliminating the offending something, she took a final look in the mirror and calmed down. In great apes, such behavior is taken as evidence of self-recognition. This had never been seen before in a bird.
On that day in 2006 we were all electrified, but at the same time the obvious question came to us: What if we were wrong? Couldn't Gerti simply have removed the sticker because she had only felt something disturbing about her feathers? Our team, which included me, Helmut Prior and Ariane Schwarz, tested Gerti again. We exchanged the yellow sticker for a black one, which was barely visible on her dark plumage. In another control experiment, she received the yellow sticker but no mirror. In both cases, Gerti made no move to peel off the paper. It only bothered her when she saw a conspicuous color mark on her plumage in the mirror. Other magpies that we tested similarly behaved similarly. As a result, these birds actually seem to recognize their own reflection.
Apart from humans, the ability for self-recognition was previously only known in a few large-brained mammals such as chimpanzees, orangutans, Indian elephants or dolphins. The fact that magpies also belong to this illustrious circle is just one of many examples of higher cognitive performance that has only been discovered in corvids and parrots in recent years. This finding throws a theory that has been dominant for more than 100 years into question. Thus, such abilities required a well-developed cerebral cortex, such as that found in mammals. But birds lack such a cortex, which is why they shouldn’t actually show outstanding cognitive performance …