What is the range of the mockingbird?

There are a number of species of mockingbird and most are tropical, but the one you are probably referring to, the northern mockingbird (referred to in Nelle Harper Lee's book), can be found from the northern part of South America, through the US to southern Canada. It is the bird that immitates many other birds and animals, and can even immitate mechanical sounds such as saws and fireworks. At the time of Ms. Lee's writing, this bird was mainly indiginous to the southern US states.