A bird that displays head bobbing while hovering is likely which of the following?

The American Kestrel is known for its unique behavior while hovering, which includes head bobbing. This characteristic posture is particularly evident as the bird maintains a stationary position in the air, searching for prey, often small mammals or insects, from a vantage point. The head bobbing allows the kestrel to enhance its vision and focus on movements in the environment below.

In contrast, the other species listed do not exhibit this specific behavior while hovering. For example, the Northern Harrier tends to fly low over grasslands and wetlands with a more fluid motion and does not engage in head bobbing. Cooper's Hawks and Red-tailed Hawks are generally more robust and exhibit different flight patterns and hunting techniques, typically relying on speed and agility rather than stationary hovering with head movements. Thus, the head bobbing behavior is a distinct characteristic of the American Kestrel, making it the correct choice in this scenario.