What environmental factor unifies the Harris's Hawk's vast geographic separation?

Answer

Association with dry, open, or semi-open country

The key unifying factor across its range is its selection of dry, open, or semi-open country, specifically arid and semi-arid regions, deserts, scrublands, and grasslands.

What environmental factor unifies the Harris's Hawk's vast geographic separation?
birdOriginhawkharris hawk