What does the blue jay represent in To Kill A Mockingbird?

a mockingbird sings for people and it does not make nests in their crops. i think bluejays are otherwise. thus, its okay to kill blue jays but you shouldn't kill mockingbirds as its a sin. because they did not do anything to harm you. a representation of a mockingbird in the book could be tom Robinson or boo radley. or even the roly poly bug in one of the chapters near the ending, when jem tell scout not to step on it cos it did not do anything to her.