Your American Kestrel is best suited to hunt...

The American Kestrel is a small falcon known for its agility and versatility in hunting. It primarily preys on a variety of small birds and insects, adapting well to urban environments and open fields. Among the choices, starlings and English sparrows represent common prey for the Kestrel, as they are relatively small, abundant, and match the Kestrel's hunting style.

Starlings are often found in larger flocks, making them a prime target, and English sparrows are frequently present in many habitats, providing the kestrel with ample opportunities for hunting.

This is why the selection that includes both starlings and English sparrows is the most suitable answer, as it accurately reflects the Kestrel's natural behaviors and hunting preferences. Quail, while a game bird, are generally larger and present a greater challenge for a bird of the Kestrel's size and hunting style, making them less suitable as primary prey. Therefore, recognizing the Kestrel's main targets helps clarify why the inclusion of both starlings and English sparrows is the best match for this question.