Not every state has a state bird and some of the states that had a state bird, have changed them once or even twice. There's no rule that says every state needs to have a state bird, but it seems to be a source of pride and identity for many states.
What's the big deal?
Having a state bird doesn't make one state better than another. It doesn't mean that one state will get more federal funding or more seats in Congress, it just means that the state has declared a bird as a state symbol. States are free to change the name of the state bird just like they're free to not name a bird as the official state bird.
The state bird is kind of a funny concept because some states don't even have an official state bird, yet the state's residents believe one bird or another to be the state bird. Usually the state bird is a bird that is very common in the state. For example, you wouldn’t make a pelican the state bird if you lived in South Dakota because it would be pretty difficult to find numerous flocks of pelicans perusing about the state.
Let's look at a few states
The state bird for Missouri is the bluebird, which is a fairly common well-known bird that lives in many other states besides Missouri. The bluebird loves to eat small insects and is known for its brightly colored blue feathers.
Hawaii has a rather interesting state bird. The Hawaiian state bird is called the nene, which is pronounced nay-nay. Though this bird has a unique name, it's pretty much the equivalent of the feces dropping geese that are found throughout the United States.
New Jersey has the eastern gold finch as its state bird. This bird is a very bright yellow and has a cone shaped beak that it uses for cracking seeds. The eastern gold finch, as the name suggests, is also found in other parts of the eastern United States.
The road runner represents Mexico's state bird. The road runner is a very fast land bird and often runs up to 17 miles an hour. Unlike other birds, the road runner prefers to keep its feet on the ground. It can fly, but it's not a good flier and would rather out run predators and chase prey via foot than via wing. The road runner is Mexico's state bird because the road runner is of great abundance in Mexico.
