How do they decide which bird is for state bird?

I would imagine it's something that each state votes on in their congress. Some state congressman was probably like, oh cardinals are red and pretty, I propose we make that the state bird.

We're not short on birds at all, we're just short on imagination, or more likely, about knowledge of wild birds.

I'm guessing it started with John James Audubon, who went out across the continental US and drew pics of the birds he saw most abundantly in the regions. Probably when state lines were established and gov'ts were formed, they looked at the collection of bird pics Audubon did to designate the bird. Since birds migrate, it's not impossible for several states to have the same bird, depending on what time of year Audubon was in that region and saw the birds.

Don't take it on me i had to say something

Great Question