Which types of hawks have completely feathered tarsi?

The correct answer indicates that the ferruginous hawk, rough-legged hawk, and golden eagle all have completely feathered tarsi. This characteristic is important in identifying these birds and understanding their adaptation to their environments.

Feathered tarsi provide insulation against cold temperatures, which is advantageous for these raptors as they often inhabit colder regions and during winter months. The ferruginous hawk and rough-legged hawk, for instance, are adapted to open grasslands and tundra where they can encounter harsh weather conditions. Similarly, the golden eagle, known for its vast range across northern hemispheres, benefits from feathered legs in maintaining body warmth during cold flights in search of prey.

In contrast, the other options include birds that do not have fully feathered tarsi. For example, the red-tailed hawk and Cooper's hawk typically exhibit unfeathered or partially feathered tarsi, which suits their hunting styles and habitats but does not provide the same insulation as those with completely feathered legs. This specific anatomical feature plays a significant role in the bird's lifestyle and survival in varying climates.