What genus includes medium to large, wide-ranging raptors known as buzzards in the Old World?

The genus that includes medium to large, wide-ranging raptors known as buzzards in the Old World is Buteo. This group of birds is characterized by their broad wings and tails, which help them soar and glide efficiently in the skies. Buteos typically inhabit a range of environments, from open fields to forests, and are known for their versatility in hunting and feeding habits.

The term "buzzard" as used in the context of the Old World primarily refers to these species, such as the common buzzard, which is found across Europe and Asia. They exhibit various adaptations that suit their predatory lifestyle, including keen eyesight and the ability to soar for long distances.

Other genera listed do not encompass the wide-ranging raptors typically referred to as buzzards. For example, Falco includes falcons, which are generally smaller and have different hunting techniques and physical characteristics. Accipiter contains hawks that are more adapted to forested environments and often have a different prey-catching strategy than the soaring style of Buteo. Strix refers exclusively to owls, which are nocturnal and have a distinctly separate ecological niche compared to buzzards. Hence, Buteo is the correct choice for this question.