It seems many people see birds not as smart as many other "higher" animals. Perhaps judged by the size of their brains. The term "bird brain" or "birdbrain" is used to describe someone who is not so smart.
Are birds really dumb?
I remember watching a video where a species of bird require the male to build a nest on the ground level. Then whoever builds the best nest will be able to attract the female in the area. So in the video, two male birds were competing with each other in the same area. Both birds had completed their nests. Then one of the two male left his nest for a while. During that time, the other male bird came to his competitor's nest to make a mess of it. He was pulling stuff out of the nest, and gave a finishing blow by repeat jumping on it. Could you believe it? A bird thinks the best way to win the competition is to destroy the competitor! He saw an opportunity and he executed the plan.
That takes more intelligent than a "birdbrain" to do it.
Could you believe it? A bird thinks the best way to win the competition is to destroy the competitor! He saw an opportunity and he executed the plan. 
