Neuroscientists' opinions about the brains of birdshave changed.
In humans and other mammals,the roof of theforebrain has evolved into the cerebral cortex, astructure responsible for flexiblelearning andreasoning.
人类和其他哺乳动物的前脑顶层已经进化为大脑皮层，这一结构主管弹性学习和推理能力。
Early neuroanatomists thought that the forebrainroof was small and simple in birds, with itsforebraininstead being dominated by structures in its base, called the basal ganglia.
早期的神经系统科学家认为鸟类的前脑顶层在大脑中面积小，构造简单，且并非由大脑基底部名为基底神经节的结构组成。
Without anelaborate forebrain roof, it seemed that birds couldn't be very smart.
因此，鸟类并不拥有复杂精妙的前脑顶层，这似乎决定了鸟类智商有限。
Recent research shows that birds are a lot smarter than scientists once thought.
To give just afew examples, the New Caledonian crow can manufacture and use tools.
The African grey parrotcan learn to classify objects into categories, and the Florida scrub jaystores food in dozens ofcaches and can remember their locations for future use.
非洲灰鹦鹉能学会对东西进行分类，佛罗里达灌丛鸦会将食物存储在不同的地方，并且能记住位置，以备将来之需。
It turns out that neuroanatomists had it all wrong about bird forebrains.
During more than 300 million years of separate evolution, the forebrain roofs of birds and ofmammals each grew largerand more elaborate, but in different ways.
