What distinguishes a ferruginous hawk from a Red-tailed Hawk?

The reason why the first choice is correct lies in the size difference between the ferruginous hawk and the red-tailed hawk. Ferruginous hawks are indeed generally larger, with a wingspan that can exceed five feet, making them one of the largest hawks in North America. This size distinction is a key identifying factor when differentiating between these two species.

The size aspect allows falconers and bird watchers to quickly recognize the ferruginous hawk in the field compared to the red-tailed hawk, which has a more moderate wingspan typically around four to four and a half feet. Understanding these physical attributes plays a significant role in bird identification and knowledge of raptor species.

While the other options may provide additional context about behaviors or classifications, they do not contribute specifically to the distinction based on size, which is critical in identifying these hawks in practice. For example, the claim regarding the defense of nests or the species classification does not directly tie into the observable size characteristics that make the ferruginous hawk stand out.