While he isn't directly referred to as a poacher in the book, his actions reflect the characteristics of a poacher:
* He hunts illegally: Ewell is known to hunt out of season, specifically for game birds.
* He disregards the law: He's shown to be a man with little respect for the law, as demonstrated by his actions against Tom Robinson and his general disregard for social norms.
* He's motivated by greed: Ewell's poaching is likely driven by a desire to provide for his family, but also by a disregard for the proper management of wildlife.
Although Ewell is the most prominent example, other characters in the book, like Mr. Radley, engage in activities that could be considered poaching, such as hunting without a license. However, Ewell's actions are the most explicitly described and represent the most significant example of poaching in the novel.