鸟类大脑奥秘，智力惊人。青蛇外传

　　It’s used as an insult – “bird brain” – not very clever. But in the last few years research has shown that this idea is out of date. This film follows scientists discovering that bird intelligence is so advanced that birds can be compared to the great apes. Some of the most sophisticated research has involved birds from the crow family, including ravens and New Caledonian crows... (展开全部)