Remarkable claims are made for some birds:
Perhaps because parrots can carefully mimic human voices (and many other sounds), many claims are made for their intelligence For example, that they understand abstractions like currency:
We are encouraged to think that the parrots have“pretty sophisticated reasoning” …
No one involved hopes that any of us will ask the obvious question: Then why are the birds not using currency themselves? It turns out that a lot of the birds were related (they grew up together), which probably helps us understand why they sought to help each other.
The paper is open access.
News, “Do birds really understand what they are saying?” at Mind Matters News
Nobody makes these claims for chickens or turkeys.
Takehome: To understand what they are saying, birds would need to understand abstractions; it’s not clear that they can.
See also: Do newborn mammals dream? But how DO they? Yale: A new Yale study suggests that, in a sense, mammals dream about the world they are about to experience before they are even born.