Roy is the protagonist in Hoot -- that is, he is the main character. However, it is important to note that this novel also tells the stories of Curly Branitt and Officer Delinko. But the story begins and ends with Roy.
Roy plays an important role in the action of the novel. Although some of the story would have progressed without Roy, the owls probably would not have been saved and the pancake house probably would have been built if Roy wasn't involved. Because Roy showed an interest in Mullet Fingers, even giving him a pair of his own shoes, Beatrice knows she can trust Roy to help her step-brother when he needs it. Without Roy's help in getting Mullet Fingers to the emergency room for his infected arm, the running boy may have died. When Roy learns about Mullet Fingers' crusade to save the owls, he decides to join him. Roy is the one who researches the owls to discover they are a protected species. His father picks up on Roy's interest and does some investigating himself, discovering that the Environmental Impact Statement is missing from the company's official file at city hall. Thus, the Mother Paula's company is embroiled in scandal and scraps its plans to build a pancake house in Coconut Cove, even going so far as to donate $50,000 to a wildlife charity. Another improvement Roy makes to his community is in standing up to the bully Dana Matherson and setting him up to be arrested.
Roy is crucial to the development of the story's theme. He is the one who chooses to get involved rather than ignore issues that most people don't take notice of. His persistence and passion for justice show that an everyday citizen, even a young person, can bring positive change to his community by getting involved and standing up for what's right.